Good first amp to build?
CLAS...@brick.net
input, assuming that's OK. I've been lurking here for a while (only
occasionally posting) and have spent many, many hours searching and
reading old posts.
http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
Would it also be acceptable to substitute a Weber Copper Cap 5R4 for
the 5U4 tube in the original?
Thanks in advance.
--Bryan
Tony Hwang
Hi,
Are you planning on using all octal socket tubes per schematics?
Then you may have little better(roomier) working space on the chassis.
Copper cap can be used OK.
If you want to dig into Marshall, Fender amsp from background up, there
is a book called "Inside Fender & Marshall Tube Amps" by JC Maillet.
I got a copy and found it very useful/informative. Another little thin
book is "The guitar amp lab book" by Acoustic Analysis Inc.
Good luck,
Tony
PMG
>Does this seem pretty straightforward? I would leave off the second
>input, assuming that's OK. I've been lurking here for a while (only
>occasionally posting) and have spent many, many hours searching and
>reading old posts.
>
>http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
Push/Pull amps aren't the normal first build amps. Lead dressing and
chassis layout issues are going to be more of a handful.
I'd start with a Champ clone, even if you're not crazy about SE amps.
I'm sure I'd go with something more common like a Deluxe clone if I
started with a push/pull amp.
That Twin seems to have unusual tubes anyhow, so take a look at
whether they're available, or if there're acceptable substitutes
available. I'm not clear what a 6SC7 is, but TDSL doesn't list any
12**7 tubes as substitutes.
Pete
>Would it also be acceptable to substitute a Weber Copper Cap 5R4 for
>the 5U4 tube in the original?
>
>Thanks in advance.
>
>--Bryan
--
Can I borrow a bucket of worms
and a keg of gunpowder? --Froggo
Phil S
<CLAS...@BRICK.NET> wrote in message
news:1118972043....@g14g2000cwa.googlegroups.com...
appears. Look into a Gilmore Jr, or a 5F1 or a AA764 Champ. Cathode bias
is good for first build. You should work your way up. Look for something
with one input jack, no more than 3 tubes (preferably with ss rectifier) and
no more than 2 pots (vol and tone). There is a great deal you will learn
along the way that just isn't obvious.
Remember, read up on safety. Safety first.
Just my 2 cents. It's based on recent personal experience. Not knowing
your background, I can't be sure, but if you can do this as a first build
with no gaffs and it doesn't hum like an Esso Bee, I'd be surprised. Too
many opportunities in this one to err.
I'd like to know how you make out. Everyone starts somewhere.
Good luck.
Phil
Phil S
"PMG" <xxxx...@comcast.net> wrote in message
news:hfb4b155c2pli61ij...@4ax.com...
> On 16 Jun 2005 18:34:03 -0700, CLAS...@BRICK.NET wrote:
>
>>Does this seem pretty straightforward? I would leave off the second
>>input, assuming that's OK. I've been lurking here for a while (only
>>occasionally posting) and have spent many, many hours searching and
>>reading old posts.
>>
>>http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
>
> Push/Pull amps aren't the normal first build amps. Lead dressing and
> chassis layout issues are going to be more of a handful.
>
> I'd start with a Champ clone, even if you're not crazy about SE amps.
>
> I'm sure I'd go with something more common like a Deluxe clone if I
> started with a push/pull amp.
>
> That Twin seems to have unusual tubes anyhow, so take a look at
> whether they're available, or if there're acceptable substitutes
> available. I'm not clear what a 6SC7 is, but TDSL doesn't list any
> 12**7 tubes as substitutes.
6SC7 roughly resembles 5751. 12AT7 might work also - similar gain, but
other values are different. But mostly your comments are the same as mine.
I think even a 5E3 (or 5C3) would be tough for a first amp. Too many parts.
Too many potential ground and lead dress issues. And the Deluxe is about as
simple as a PP amp gets, next to a Gilmore Jr.
CLAS...@brick.net
PMG wrote:
> On 16 Jun 2005 18:34:03 -0700, CLAS...@BRICK.NET wrote:
>
> >Does this seem pretty straightforward? I would leave off the second
> >input, assuming that's OK. I've been lurking here for a while (only
> >occasionally posting) and have spent many, many hours searching and
> >reading old posts.
> >
> >http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
>
> Push/Pull amps aren't the normal first build amps. Lead dressing and
> chassis layout issues are going to be more of a handful.
>
> I'd start with a Champ clone, even if you're not crazy about SE amps.
I already own two of those, an Epiphone Galaxie (SS rectifier) and a
homemade jobbie (from the 40s?)
>
> I'm sure I'd go with something more common like a Deluxe clone if I
> started with a push/pull amp.
I agree, after looking at the schematic. Thanks.
>
> That Twin seems to have unusual tubes anyhow, so take a look at
> whether they're available, or if there're acceptable substitutes
> available. I'm not clear what a 6SC7 is, but TDSL doesn't list any
> 12**7 tubes as substitutes.
Plenty of NOS 6SC7s left out there, and the Deluxe (5C3) uses them too.
>
> Pete
>
> >Would it also be acceptable to substitute a Weber Copper Cap 5R4 for
> >the 5U4 tube in the original?
> >
> >Thanks in advance.
> >
> >--Bryan
--Bryan
CLAS...@brick.net
Phil S wrote:
> <CLAS...@BRICK.NET> wrote in message
> news:1118972043....@g14g2000cwa.googlegroups.com...
> > Does this seem pretty straightforward? I would leave off the second
> > input, assuming that's OK. I've been lurking here for a while (only
> > occasionally posting) and have spent many, many hours searching and
> > reading old posts.
> >
> > http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
> >
> > Would it also be acceptable to substitute a Weber Copper Cap 5R4 for
> > the 5U4 tube in the original?
> >
> > Thanks in advance.
> >
> > --Bryan
> >
> Four pots, five tubes, four input jacks. It's more complicated than it
> appears. Look into a Gilmore Jr, or a 5F1 or a AA764 Champ. Cathode bias
> is good for first build. You should work your way up. Look for something
> with one input jack, no more than 3 tubes (preferably with ss rectifier)
If the ONLY purpose was to learn, maybe, but I want to build something
with the potential to be really nice. Not just another little thing
that's practically indistinguishable from my Epiphone Galaxie.
> and no more than 2 pots (vol and tone). There is a great deal you will
> learn along the way that just isn't obvious.
>
> Remember, read up on safety. Safety first.
I am a fraidy cat, bigtime.
>
> Just my 2 cents. It's based on recent personal experience. Not knowing
> your background, I can't be sure, but if you can do this as a first build
> with no gaffs and it doesn't hum like an Esso Bee, I'd be surprised. Too
> many opportunities in this one to err.
If it were a little SS project, no big deal at all. I'm 44 YO, so I've
soldered a few transistor circuits in my youth. Where would you figure
hum would come from? Just curious. If I do it, I'll overbuild it as
far as shielded wire, nice transformers, etc.
>
> I'd like to know how you make out. Everyone starts somewhere.
Oh, you can bet I'll post here if I do this. The suggestion from
another poster about the Deluxe being a better choice seems right.
>
> Good luck.
Thank You.
> Phil
--Bryan
John Wheaton
<CLAS...@BRICK.NET> wrote in message Not just another little thing
> that's practically indistinguishable from my Epiphone Galaxie.
>
The amp that I use the most is a Tweed Princeton Clone in a SF Champ box,
with a Weber speaker. Saying that is my favorite amp is something since I
have a BF Super Reverb, BF Deluxe Reverb, BF Princeton, and a BF Champ.
See ya,
John
Ether
Phil S wrote:
> "PMG" <xxxx...@comcast.net> wrote in message
> news:hfb4b155c2pli61ij...@4ax.com...
> > On 16 Jun 2005 18:34:03 -0700, CLAS...@BRICK.NET wrote:
> >
> >>Does this seem pretty straightforward? I would leave off the second
> >>input, assuming that's OK. I've been lurking here for a while (only
> >>occasionally posting) and have spent many, many hours searching and
> >>reading old posts.
> >>
> >>http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
> >
> > Push/Pull amps aren't the normal first build amps. Lead dressing and
> > chassis layout issues are going to be more of a handful.
> >
> > I'd start with a Champ clone, even if you're not crazy about SE amps.
> >
> > I'm sure I'd go with something more common like a Deluxe clone if I
> > started with a push/pull amp.
> >
> > That Twin seems to have unusual tubes anyhow, so take a look at
> > whether they're available, or if there're acceptable substitutes
> > available. I'm not clear what a 6SC7 is, but TDSL doesn't list any
> > 12**7 tubes as substitutes.
>
> 6SC7 roughly resembles 5751. 12AT7 might work also - similar gain, but
> other values are different. But mostly your comments are the same as mine.
> I think even a 5E3 (or 5C3) would be tough for a first amp. Too many parts.
> Too many potential ground and lead dress issues. And the Deluxe is about as
> simple as a PP amp gets, next to a Gilmore Jr.
A 5E3 Deluxe was my first build. Took a lot of time, but if you can
solder, it's easy. (I should add: If you can follow a schematic, and
you're careful about details. Best if you use a repro chassis--to avoid
potential layout-induced headaches.) Rockin' amp, too.
Regards,
--E
Ether
Hello, Bryan--
It strikes me that a "C" series Fender tweed amp is a pretty funky one
for a first-time build. A lot of them sounded great, though. I loved
the tone of a 5C5 Tweed Pro I played last year.
But Fender made changes in their circuits for a reason--to overcome
problems & limitations, and also to simplify the circuit. That's why
most people build "E" or "F" series tweed amps. They're the ones at the
end of the tweed line, and many of them became classics.
Octal preamp tubes are harder to find, too. But if that's your cup of
tea, then fine. Octal preamp tubes do have a somewhat fatter tone than
9-pin miniatures, at least in my experience.
If you're going to build this in a scavenged chassis, you may run into
oscillation & hum issues from lead dress & layout problems if you're
not careful (and even maybe if you are). If you're going to put this
much effort into a project, I'd use a repro Fender chassis.
And if I were going to put this much effort in to a Tweed Twin build,
I'd probably do the later 5E8-A ("low-power" Twin) circuit.
As for a 5V4--yes, you can most likely use it without any trouble. A
5V4 has about 19 volts less forward drop, so the B+ voltage will be a
little bit higher.
Good luck!
--E
Phil S
"Ether" <et...@x-mail.net> wrote in message
news:1118981145.5...@f14g2000cwb.googlegroups.com...
Agreed. Patience will be a necessary ingredient, in addition to willingness
to pay for a proper chassis and board that were made for it. I think Weber
has one for a decent price.
Phil S
<CLAS...@BRICK.NET> wrote in message
news:1118978978.5...@g44g2000cwa.googlegroups.com...
of your bench to drill them in. Stuff like rubber sole shoes, hand in
pocket, remember to bleed caps, etc.
>>
>> Just my 2 cents. It's based on recent personal experience. Not knowing
>> your background, I can't be sure, but if you can do this as a first build
>> with no gaffs and it doesn't hum like an Esso Bee, I'd be surprised. Too
>> many opportunities in this one to err.
>
> If it were a little SS project, no big deal at all. I'm 44 YO, so I've
> soldered a few transistor circuits in my youth. Where would you figure
> hum would come from? Just curious. If I do it, I'll overbuild it as
> far as shielded wire, nice transformers, etc.
Careful about "overbuild". Good trannies are a nice touch, but I'd keep it
to a dull roar and save my money for a later project. This one is partly
just for the experience (even if you think it might not be so). MM trannies
are for when you have more experience, IMO. I use sheilded cable to
compensate for layout mistakes. Since I like to build from recycled junk, I
sometimes have some long runs of wire that are problemmatic. You shouldn't
need sheilded cable. I'd avoid it, and it really shouldn't be necessary.
My run-in's with hum have typically been from my lack of understanding of
how to apply a proper ground scheme. Once you get the hang of that, things
go much better. Then, there was the amp with no bottom plate...I cut down a
Beware of Dog sign ($1.29, Home Depot), and it worked wonders (thanks, LV)!
You can also induce both hum and oscillation from poor wire placement. I've
been surprised what I can do with a chopstick on a live chassis. Sometimes,
the slightest nudge is enough to make a big difference.
We haven't taken a census, but I'll guess you're actually on the younger end
of those who hang out here, though not by much. ;~}
>>
>> I'd like to know how you make out. Everyone starts somewhere.
>
> Oh, you can bet I'll post here if I do this. The suggestion from
> another poster about the Deluxe being a better choice seems right.
Look at Weber's 5E3 kit. Resonably priced. Decent but not top of the line
quality. I think you'll be happy with that.
PMG
>
>
>PMG wrote:
>> On 16 Jun 2005 18:34:03 -0700, CLAS...@BRICK.NET wrote:
>>
>> >Does this seem pretty straightforward? I would leave off the second
>> >input, assuming that's OK. I've been lurking here for a while (only
>> >occasionally posting) and have spent many, many hours searching and
>> >reading old posts.
>> >
>> >http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
>>
>> Push/Pull amps aren't the normal first build amps. Lead dressing and
>> chassis layout issues are going to be more of a handful.
>>
>> I'd start with a Champ clone, even if you're not crazy about SE amps.
>
>I already own two of those, an Epiphone Galaxie (SS rectifier) and a
>homemade jobbie (from the 40s?)
>>
>> I'm sure I'd go with something more common like a Deluxe clone if I
>> started with a push/pull amp.
>
>I agree, after looking at the schematic. Thanks.
>>
>> That Twin seems to have unusual tubes anyhow, so take a look at
>> whether they're available, or if there're acceptable substitutes
>> available. I'm not clear what a 6SC7 is, but TDSL doesn't list any
>> 12**7 tubes as substitutes.
>
>Plenty of NOS 6SC7s left out there, and the Deluxe (5C3) uses them too.
I wasn't sharp enough to notice that those 6SC7s are octal tubes!
Oops.
I guess I'd probably want to build a BF era Deluxe then if the Tweed
ones use that too.
Pete
Jim Anable
> <CLAS...@BRICK.NET> wrote in message
> news:1118972043....@g14g2000cwa.googlegroups.com...
>
>>Does this seem pretty straightforward? I would leave off the second
>>input, assuming that's OK. I've been lurking here for a while (only
>>occasionally posting) and have spent many, many hours searching and
>>reading old posts.
>>
>>http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
>>
>>Would it also be acceptable to substitute a Weber Copper Cap 5R4 for
>>the 5U4 tube in the original?
>>
>>Thanks in advance.
>>
>>--Bryan
>>
>
> Four pots, five tubes, four input jacks. It's more complicated than it
> appears.
I agree. However, I happen to have an old amp with the right start for
this type of thing. If you can find a similar starting point, it would
be MUCH, MUCH easier.
Here's mine:
http://www.seattle-attorney.com/sc1.jpg
http://www.seattle-attorney.com/sc2.jpg
http://www.seattle-attorney.com/sc3.jpg
lbrt...@aol.com
has more worth & desireability as the vintage PA it is, if gone
through. I'd restore it. But if you're intent on hacking it up, great
copperplated chassis with everything already in the right place & no
extra garbage to rip off or leave gaping fugly holes. NOTE: one does
well to check the iron on old PA's prior to any decision to devalue
them into a fun guitar amp, because most (not all) of them have
higher-ratio OPT's that don't sound great nor deliver good guitar-type
power performance. Guitar amps tend to run the tubes down on a heavier
loadline using lower load impedance, while PA's & vintage hifi's run
higher impedance loadlines for less power at less distortion. Often,
but not always, the PT is marginal current-wise or at a less ideal B+
secondary voltage, too, for guitar service, not to mention many (not
all) old PT's tend to be a little deteriorated past the point where one
wants to push them even harder than their original equipment for
guitar-type loads. Frequently, when the iron is taken into
consideration, one finds it wiser to preserve the piece - particularly
a nice little S-C like this. OTOH when one does have favorable PT
specs and the (uncommon) good OPT ratio for guitar use, then the OPT
will handle about 2x its orginally rated RMS pwr in a typical guitar
amp design (because nothing below 88hz is needed).
You can get the details on the iron by obtaining a Sam's schematic
folder for it - Sam's always lists transformer details in their parts
list, unlike most Rider's (Rider & Sam's overlap for this period). I
cannot verify the model # in your pic but if you have it, I may have
the folder for it & could double-check the info, or if not you may
order a copy of the folder from online providers for abt $20.
Lacking that, it is definitely an AU-32 type or its nearly-idential
successor and I can tell you for certain that:
- it originally used 6L6G's (not GC's, GB's or 5881's), for a rated
"audio output" of 32 watts, meaning a real RMS of around half that;
- it has a pair of JAN/MIL fat-based 6L6 variants stuck in the holes
which are not known for sounding great, but rather were made for high
shock/vibration resistance;
- it's OPT has a 4.5k pri (great!) but isn't rated (wound) for the
current that 6L6GC's typically require (not so great), and 6V6's are
out of the question;
- it's PT is rated at 680VCT (great!) but only 120ma (not so great &
also inadequate for even light PP 6L6 guitar amp service unless pushed
well beyond its current rating).
IOW iron-wise, your piece is sort of half-good for a guitar amp, which
is better than many of that era, but still cause for reflection.
For example, this could make a decent Deluxe-type with its PT & 6V6's,
if you bought a new Deluxe OPT (cheap), and you'd have to chuck all the
rest of its guts (caps & res) & could reuse the boards, and you prolly
want to chuck its big funky nice case, too, to stuff it in a more
suitable cab (which also must be made or bought).
So, you can weigh that against having a rather cool vintage PA that
sounds pretty good restored, won't be overworked even if it's cranked
open, and holds value. I have done dozens of these, and they are not
very expensive to do. They can sound good for harp, or for modern
flat/clean uses like separate FX or piezo, as long as the noise
threshold isn't very important (the hum of old tube gear vs modern SS).
HTH,
-f.
Phil S
<lbrt...@aol.com> wrote in message
news:1119054985.4...@g49g2000cwa.googlegroups.com...
Save the $20 on the Sams by getting it for free at your local municipal free
public library. Well, it will cost you under a buck to photocopy it. Most
either have them or will get them for you on inter-library loan. Others
have a subscription to the Sams database.
Phil
Ether
PMG wrote:
> On 16 Jun 2005 20:19:50 -0700, CLAS...@BRICK.NET wrote:
>
> >
> >
> >PMG wrote:
> >> On 16 Jun 2005 18:34:03 -0700, CLAS...@BRICK.NET wrote:
> >>
> >> >Does this seem pretty straightforward? I would leave off the second
> >> >input, assuming that's OK. I've been lurking here for a while (only
> >> >occasionally posting) and have spent many, many hours searching and
> >> >reading old posts.
> >> >
> >> >http://www.kbapps.com/audio/schematics/tubeamps/fender/twin5c8.html
> >>
> >> Push/Pull amps aren't the normal first build amps. Lead dressing and
> >> chassis layout issues are going to be more of a handful.
> >>
> >> I'd start with a Champ clone, even if you're not crazy about SE amps.
> >
> >I already own two of those, an Epiphone Galaxie (SS rectifier) and a
> >homemade jobbie (from the 40s?)
> >>
> >> I'm sure I'd go with something more common like a Deluxe clone if I
> >> started with a push/pull amp.
> >
> >I agree, after looking at the schematic. Thanks.
> >>
> >> That Twin seems to have unusual tubes anyhow, so take a look at
> >> whether they're available, or if there're acceptable substitutes
> >> available. I'm not clear what a 6SC7 is, but TDSL doesn't list any
> >> 12**7 tubes as substitutes.
> >
> >Plenty of NOS 6SC7s left out there, and the Deluxe (5C3) uses them too.
>
> I wasn't sharp enough to notice that those 6SC7s are octal tubes!
>
That's why I get paid the big bucks! ;)
>
> Oops.
Hey--it happens. (At least you didn't proclaim that all Pro Reverbs
have two speakers.)
>
> I guess I'd probably want to build a BF era Deluxe then if the Tweed
> ones use that too.
Eh? The later Tweed Deluxes (5D3, 5E3) use the typical 9-pin preamp
tubes: 12AY7 & 12AX7. So does the Brown Deluxe (6G3). So you don't
have to leap *all* the way into the future like that!
Regards,
--E
Ether
Lbrty, I'm impressed--a good post with a lot of useful information, and
nigh all of it correct! No pontificating, either. Did somebody steal
your computer? ;)
--E
lbrt...@aol.com
differ from some other views:
1) I strongly suggest you at least play an original version of any amp
ckt to be copied before committing or even investigating very far into
building it. If you cannot, then build one you have played. (And not
"heard someone else sound great playing" instead.)
2) Take aboard what another said about the C-series. This was still
the crude, uninformed and experimental era of trying to mass-produce an
amp that was cheap to build with cheap Mexican immigrant labor and
adequate in performance & tone during a postwar recovery when a
linoleum kitchen floor was still a luxury to many. Amps still had a
long way to go with all mfg'rs of this era. There are good reasons why
we traded our tweeds off in rapid succession as soon as improved models
came out (and as soon as we had the $$ & gigs enough to contemplate
it).
3) Do not be intimidated by "a complex circuit." When I was 9 years
old I built a whole AA5 radio from scratch on an ugly long piece of
Masonite with fake bathroom tile on its underside for a science fair
entry (so I could point out how it works signal-wise in a linear,
easy-to-show-and-tell layout), just by copying a PTP wired radio I
dissected. This included aligning it using the local oscillator of
another radio and no test gear, which is actually pretty simple. After
my crappy solder joints were touched up it worked perfectly for the
next 2 years of being dragged around to buddies' houses and dropped a
few times, including once from a treehouse (yes we had power up there).
IMCO there is no such thing as a complex traditional tube guitar amp
circuit or project, if you have made it past the 4th grade on your own
intellectual abilites. There is no RF in a guitar amp (intentionally,
at least), so you are already better off than I was at 9 in terms of
challenge, complexity, wiring considerations and the like. Please
don't buy into the dumb-down. It will cost you.
4) I'd forget any tube rectifier or any "substitute" for one at any
price. There simply is no need nor musical excuse for having one, and
as soon as SS diodes became cheap & reliable, all the better amps
started getting rid of tube rect's too. 1N007's are $0.10 apiece
retail, and if for some perverse reason, myth or peer pressure you HAVE
TO have more drop, put a resistor on it & be done with it. Save
yourself time, money, another hole in the chassis, more heat to
dissipate, more energy wasted, more load on the PT, another firebottle
to buy & maintain, lousier bottom end response & less punch. Don't you
know that the "dual rectfier" idea is straight from the failed interim
tweed Bassman that resorted to 2x5U4 to try to get something solid out
of itself? Don't you know they even resorted to a mercury rectifier
for its lower drop as another half-assed interim solution? We had to
live & gig with this shit, and f&#k with them when they failed (which
was often), and we knew it was shit then and called it that! Rect
tubes were cheap, HV seleniums were expensive & problematic, and SS
diodes were flaky and costly for the ratings & number required. All
this changed 45 years ago. Come out of the past, all the myths about
tonal superiority that never was, and the silly notion that an already
very saggy supply needs even more "sag" from a now-expensive double
resistor that glows in the dark. The only remaining justification used
for a tube rect is in small amps with no STBY switch for the
newly-supposed horror of cathode-stripping, which is insignificant in
these amps vis-a-vis their practical tube life and they, too, need all
the help they can get with superior SS diodes. Frankly, you'd think
that the over-praised fools who sell books and magazines with these
dumbassed ideas as "truths" had just discovered the finer points of a
technology & gear that were more well-known 50 years ago by most
everyone who was weaned from the nipple, but they are still sucking
hind teat while passing it off as the finest Scotch.
5) Do not waste time researching, reading, "designing", inquiring, and
otherwise contemplating this "complex project" (NOT) anymore. Grab
some shit and make something out of it. It is very hard to screw up a
plain, traditional-type guitar amp build from a hobbyist standpoint.
You have possibly been taken in & snookered by all the hoo-haa "all
about amps." You could die without notice in 10 seconds at any age -
as most people tend to die without notice - having "researched" forever
something you never got to experience or play. In true value terms,
you have probably already spent over $2,000 worth of resources
"researching what to build" in mere time alone. It is easy to overlook
this because the guitar scene deals in evaluating images rather than
logic and results.
6) Stop looking for more ways to spend more money and get rooked by
vendors who want to gratify your emotional fantasy at an attractive
margin. If you REALLY think some particular part is going to make some
huge difference, then change to it LATER after you know for real and
firsthand what an ORDINARY part does for you. If you don't believe me
about rectumfriers, then put a rectumfrier socket in it, smash a dead
tube for its pin plug, put your nice little SS diodes in that, and you
can try out toob rectumfriers to your heart's content LATER. When you
finally prove you don't need a tube rect, you can yank the socket, wire
in the SS diodes under the chassis where they belong and put an
accessory outlet or maybe a trem or 'verb tube in its place (something
useful to you).
7) Forget completely about the notion of "my first amp project", it is
a fun thought but mostly a waste of time, money and effort. ONLY BUILD
THE AMP YOU WANT TO KEEP AND PLAY FOR A LONG TIME - even if it is a
400 watt class AB2 monster with 8 power tubes and an opamp based FX
loop with built-in digital delay, 2 chassis, 6 boards and 537 solder
joints or whatever. Or, if it happens to be a one-tube headphone amp.
Anything less than what you really want to play through will quickly
become a near-unsaleable piece of junk and a dust collector, no matter
how perfect it may look or even work, nor if it has the most expensive
nice "vintage" cab from Vibratorchronic, or parts from Groove Boobs and
Venus Dragnetics, or whomever. The alternative is exactly what kit
marketers hope you will do: study about, buy & build every one of
their costly assortments of well marked-up parts in succession "as you
progress and move up", until your house is half full of what looks like
1940's low-end luggage. :-) If you just want something to learn how
to assemble & solder with, get an old non-colletible tube radio for $15
that works somewhat, disassemble it, and reassemble it with all the
same parts, without wrecking any of them. You will learn more about
soldering, unsoldering, component wiring and assembly than building six
amp kits and it will cost you almost nothing.
8) A prepunched guitar amp chassis is about the most wasteful, high
markup sales idea yet devised by mere men. You can buy a set of real
chassis punches for what such a chassis costs, and they will last you &
your heirs several lifetimes unless you do something really stupid with
them. You can also make a superior layout, even as a beginner, with a
little thought. Aluminum chassis are reasonably inexpensive (if still
overpriced), electrically superior to steel and very easy to lay out &
work with ordinary tools. Making your own chassis is also simple and
very cheap if you have access to a small, simple sheetmetal brake - or
even without one if you are skilled with a hammer and block. Unless
you envision the possibility of your amp being dropped off a loading
dock or an airport luggage tug (i.e., you are a working player and
going on tour where this sh*t really happens), avoid steel entirely.
It is noisier, heavier, harder to work, rusts and is a waste of money.
If you were a working player going on tour, you wouldn't be building
your first amp, or at least you surely wouldn't be wondering what is
best for you and asking others who are strangers.
9) Consider getting rid of other "traditional" but useless, expensive
or dumb construction features "just because most amps look that way."
These include Grilled Cloth, Numb(ered) Knobs, Chassis Mounting Scraps,
little ball-bearing rolling Castrators, Fall-on-its-Back Legs,
Scrap-Type Handles, Toilettex Covering, TweetyBird covering, Glass Door
& Knee Smashing Steel Coroner Protectors, flimsy back panels, and other
stupid, expensive, worthless things that have long proven their vanity
and futility. If you really want something that looks like the F-word,
M-word, V-word or G-word, go buy a real one instead (and live with all
these dumb things for the sole advantage of being able to trade it in
when you get bored with it). It will be far cheaper in the end. If
you are going to build, build something that is easy to use, carry,
load & transport without wrecking a nice car or truck or destroying
your playing fingers, that is robust and attractive, actually projects
sound, is hard to damage, doesn't collect dirt, and is made for someone
who knows how to play guitar (hopefully yourself). Think outside the
box and practically instead of trying to match commercial marketing
ideas that do absolutely nothing for tone, performance or utility or
even lasting appearance, and often inhibit them all.
10) Don't buy any parts from "guitar amp" vendors that you don't HAVE
TO. It is like buying stainless steel screws for your sailboat from
all the marinas you tie up to, or buying new sneakers from the golf pro
shop at the country club. You need excellent speaker(s) and tubes from
wise and fair guitar amp vendors, and you may (or may not!) need an OPT
for your particular design from one of them, too. Everything else you
can buy from regular parts suppliers, just as I and other custom
builders do.
11) Kit, schmidt!! EVERY build by everyone, even in a factory, is a
kit! Kit up your own job completely before you start, like any other
project, using drawings and a B/M, however simple or informal. Actual
assembly is the fastest, easiest and cheapest part of it all. All you
are really buying in a kit, is thinly disguised emotional and
intellectual support at a high financial price. If you need either one
that badly from some vendor, you're going to have a helluva time trying
to play decent music.
12) Take your new aluminum chassis and DO NOT remove, loosen nor
damage its wrapping paper! - or, cover the one you made tightly &
neatly with brown kraft paper taut all over, same. Place your
mountable parts on the chassis and move them around, measuring & etc,
until you are happy with their layout. Mark them and lay out all other
fab work to be done right on the paper, using normal layout tools.
Centerpunch right through it as necessary. Do all drilling, including
arbor holes for socket punches & such, before you remove the paper.
Not only will this save you a lot of time and scribing, but it is much
easier and most of the chips will stay inside the wrapped-up chassis,
saving a mess. It is also much easier to erase wrong pencilmarks or
changes from paper, than dealing with mis-scribed lines in metal (you
will ALWAYS cut the wrongly-scribed line, trust me). If you want a
nice satin finish on your finished-fabbed aluminum chassis, degrease it
and soak it in lye. The most stupid thing novices do is unwrap the new
chassis on arrival "to look at it."
13) Forget about using a board for anything, unless you have a
particular modular section (like a SS subassembly, for example) to
incorporate, or perhaps for your bias supply if it is a strange or
freaky complex affair of its own (highly unlikely). Instead, plan
where your component leads will attach to tubesockets, pots and other
chassis-mount parts, and provide a minimum but well-placed number of
terminal strips to accommodate (1) any "flying" connections and (2) any
multiple-lead connections that exceed in number of leads the terminals
on your sockets & pots can accommodate (and they will accommodate more
leads than you think they will if you attach them right - did you
disect & reassemble that radio yet?).
14) Mechanically wire all the component leads securely and trim them -
every one, meaning build the whole chassis - before you plug in the
soldering iron. Work carefully with proper tools so as not to
over-stress nor destroy any terminals. If the amp survives your
mechanical assembly of connections, it will survive anything that
follows for many years. Then after checking all your work and
connections against your plans and schematic, solder them all at once.
This will give you the most uniform results with the least chance for
errors or missed or cold solder joints. Do NOT rely upon solder for
the integrity of any connection! If any connection looks shitty or is
loose or funky before soldering, DO IT AGAIN FIRST. It is the novice
or boob who assembles or solders up a chassis one part at a time, as
most kits instruct for such boobs to do, and much error and low quality
comes thereof. The very same goes for board (ugh) construction -
solder up a whole board at once, never part-by-part. The only
exception to this is when there is more than one layer of components
with one layer obstructing the joints of another. In such a case (it
won't be yours), assemble & solder a whole layer, then the next.
15) Repairing and building get mixed together in online discussion
groups and such. But both are different skills that involve different
methods, thinking, mindset & priorites. Few repairmen or techs are
builders, though they may casually build something now & then that is
quite nice, and some expert builders are not very skilled at repair and
can screw around forever. There is nothing wrong, and everything
right, with this. As in the automotive world, there are also both
mechanics and builders who are idiots or geniusses at either or both,
yet somehow they are still around & busy, and despite this no one
expects an expert mechanic to be a car builder or vice versa. Don't
expect a lot of building insight from amp techs, even some of the aces
- it isn't their thing, though there are a few here expert at both.
The same goes for houses that primarily sell repair or restoration
parts, but offer supplies and "info" for builders. None of this is
meant as a diss. Building isn't tech-ing. Certainly a competent tech
who becomes a builder becomes an excellent one, by knowing 300 repair
issues to try to avoid up-front. Learn some of it firsthand yourself,
rather than relying upon a lot of newgroup advice (and much of it from
very smart people). The best easily-accessed source of tube building
construction practices is literature (offline) from the hands-on ham
radio era prior to 1970, and personal mentoring of those who were
steeped in it when most people of average means built their own gear to
high standards because the alternative was not affordable, and without
high quality construction the gear was unreliable, deadly or unuseable.
The guitar amp scene is a poor place to learn about good building with
a technology that is long dead & surpassed except for its musical
interests & value.
To sum up, if you approach it with logic and linear, factual reasoning
& skills-building instead of images and their image-oriented packaged
or populist solutions, even the simplest amp can be a very rewarding
experience and a long-treasured piece of gear - and a financially
sensible undertaking for a change.
- f.
lbrt...@aol.com
PMG
I don't get paid squat.
That's my excuse, and I'm sticking to it.
>> Oops.
>
>Hey--it happens. (At least you didn't proclaim that all Pro Reverbs
>have two speakers.)
I wasn't following the discursion, but I'm sure that he meant that all
the ones worth owning have two speakers.
>> I guess I'd probably want to build a BF era Deluxe then if the Tweed
>> ones use that too.
>
>Eh? The later Tweed Deluxes (5D3, 5E3) use the typical 9-pin preamp
>tubes: 12AY7 & 12AX7. So does the Brown Deluxe (6G3). So you don't
>have to leap *all* the way into the future like that!
>
>Regards,
>
> --E
"The future's so bright... I gotta wear shades..."
I'd rather build an amp in a SF or BF chassis anyhow personally. I
appreciate how quickly you can open up a Tweed amp. Much easier than
pulling the chassis out in BF & SF amps, but I'd rather have
everything laid out all flat, and in the open, instead of the cramped
space of a Tweed chassis. I guess you could build a Tweed amp into a
SF chassis. I'm sure that would work out.
John Wheaton
> appreciate how quickly you can open up a Tweed amp. Much easier than
> pulling the chassis out in BF & SF amps, but I'd rather have
> everything laid out all flat, and in the open, instead of the cramped
> space of a Tweed chassis. I guess you could build a Tweed amp into a
> SF chassis. I'm sure that would work out.
>
I have a SF Champ that was gutted and rebuilt with new inerds, and a push,
pull volume knob. With the volume knob in, it`s a BF Champ, with the volume
knob pulled out, it`s a Tweed. I love the amp! I have a BF Super Reverb, BF
Deluxe Reverb, BF Princeton, and a BF Champ, but the amp that I use around
the house is the Tweed Clone in the SF chassis.
See ya,
John
lbrt...@aol.com
> "PMG" <xxxx...@comcast.net> wrote in message >
> > I'd rather build an amp in a SF or BF chassis anyhow personally. I
> > appreciate how quickly you can open up a Tweed amp. Much easier than
> > pulling the chassis out in BF & SF amps, but I'd rather have
> > everything laid out all flat, and in the open, instead of the cramped
> > space of a Tweed chassis.
Why? What difference does it make?
> I have a SF Champ that was gutted and rebuilt with new inerds, and a push,
> pull volume knob. With the volume knob in, it`s a BF Champ, with the volume
> knob pulled out, it`s a Tweed. I love the amp!
That is a very cool and easy idea for the Champ enthusiast who plays at
home.
One of my builds I use most when not using my BFPR/Roland biamp working
setup is a PR-derived ckt (but in 35w territory) with a second whole
tweed 12AY7 front end. Either front end (and their separate controls)
is switched simply by plugging into one jack or another. It is very
versatile and like having two nice wives with you at once - one a
classy model, the other a church-going nympho. But it's not a design
I'd marry, just take to interesting short dates where I need the most
tube-type variety out of one piece of gear that is compact.
This happens to be the last amp I fitted with push-pull fixed
bias/cathode bias option, before finally admitting that cathode bias is
an utterly useless option in a PP AB1 guitar amp for serious playing.
It was just an excuse to use up the high quality push-pull 25k pots I
had around. This is a disease which can infect even expert builders,
from individuals to big factories: "I'll design/use/add goodie XYZ to
the thing just because I have it...it will be cool..." without a sound
mission & purpose to justify it.
If I ever do another build for MYSELF again for a present-day working
combo, it will have no control pots or knobs at all, because I never
use nor need them; for me they are a waste of parts, space, clutter,
maintenance, fabrication & installation labor, and money. Not to
mention that it is getting harder to find or buy new pots that are not
trash in one way or another at any price. Set/forget trimmers
accessible with an alignment tool will suffice. A pilot light is
equally useless to me. But I suppose some will come up and say:
"Amazing kickass speaker, where's your amp?". Maybe I will BS them &
tell them it's inside the guitar. ;-)
gtski
I LIKE that idea..! ! ! The whole thing could be about 3 inches
wide... little tiny holes to access the trim pots, keep the alignment
tool in your pocket. I'd have to have a volume control though...
maybe make it a real BIG knob... ;-)
gtski
CLAS...@brick.net
Then people'd say, "That guy hasn't got much of an amp, but he sure
does have a big knob!"
>
> gtski
--Bryan
Phil S
<lbrt...@aol.com> wrote in message
news:1119071896.8...@g43g2000cwa.googlegroups.com...
> After almost 50 yrs of building crap to gold & in-between, I'm going to
> differ from some other views:
>
<snip excellent content for brevity>
> To sum up, if you approach it with logic and linear, factual reasoning
> & skills-building instead of images and their image-oriented packaged
> or populist solutions, even the simplest amp can be a very rewarding
> experience and a long-treasured piece of gear - and a financially
> sensible undertaking for a change.
>
> - f.
>
Frank,
I'd like to offer my compliments and thanks for a well written, thoughtful,
and informative article on guitar amp building. I think we should all
recognize the editorial nature of the article -- these are your well
reasoned and clearly articulated opinions. So, there will be some other
thoughts, and I feel like putting in my well-intentioned 2 cents.
You and I are far apart on the continuum of expertise. I am a rank ameteur
who builds low cost random projects from junk for the entertainment value
and the hope that just maybe I'll like what I build well enough to use it.
I'm one for two on that score (as so-so Frankenchamp, and a window-shaking
Franken-5e3) and soon to try a third project. This is no digression from
the topic, rather to set the stage for a slightly different point of view
from someone who is not very far ahead of the OP. I know this approach is
180 degrees from your recommendation to play the amp before building and to
select the project you really want. It's excellent advice and difficult to
argue for something else. Unfortunately, to really evaluate an amp, I think
you've got to find it and then take it home -- do more than just noodle
around with it at a music store -- or if you are so fortunate, in someone
else's "studio". This may not be a realistic option for some people, and
so a test drive and a leap of faith may be the best they can do. Besides,
the thing that gets built, particularly if a complex circuit by an
inexperienced builder, is likely to have some unintentional and unnoticed
variation introduced and never identified.
I particularly enjoyed your chassis discussion. Building from junk, and not
having access to any sophisticated tools (and too cheap to buy them), I
found a few things that, while not as elegant as a break and set of punches,
get the job done. Somehow, in my mind, the cost of a set of punches isn't
"justifiable" for me. Instead, it is probably easy enough for the casual
builder to employ a pair of step-drills. These are very easy to use and
make nice clean round holes that typically need little or no deburring. One
is needed for 1/4" to ~1" and another for larger sizes, maybe 3/4" to 1.5"
or there abouts. (As an amateur, time is something that is on my side. I
was able to buy decent name-brand step drills, new in package, on eBay for
very reasonable prices. If paying retail for these, you might as well just
get the punches.)
I've found that I can use the drill, a file, and hand-held hack saw blade to
cut the various square or rectangle holes. Yes, it takes some patience and
decent manual skills. Drill the hole, file one side flat and tangent to the
circle, carefully cut with the saw, then a lotta filing to get it just
right. I hear it comming...this is too much work. Yes, it is a PITA, but
OK if all you need is a hole for the IEC connector and another for a PT.
I own one of those silly Black and Decker Workmate benches. I've had it for
maybe 20 years or more. It's the crummy little one. It's long jaws happen
to make a decent place to bend metal. Not nearly as nice as a break, but
size-wise, with the benefit of hammer and blocks it works very well. If I
can do a decent bend on this thing, anyone can. I'm all for rolling your
own whenever possible. And it's my sense the aluminum will be much easier
to bend than steel.
I really like your recommendation to cover the amp with paper. Somehow, I
didn't think of doing that. But, I think there is an easy alternative.
Rather than scribe the chassis, mark it with a fine point Sharpie. Mistakes
are easily removed with a rag and alchohol. It's tidy, quick and
convenient. Oh, yeah, always drill into a wood block underneath the metal.
Regarding building on a board, I'd differ with you here just a bit. I've
done it PTP with terminal strips and the like. This is a huge challenge for
a beginer. For a basic circuit like a Champ, I'd say, well, OK. On
something more complicated, the untrained eye and brain will be very
challenged to get through it. An eyelet or turret board offers an easy way
of organizing the components and will probably cut down on the frustration
factor and the possibility of error. There is a guy selling decent turret
boards for "popular models" on eBay for ~$20. I just bought one and the
quality appears to be excellent. No, I wouldn't pay $50 for one, and
probably woundn't pay $30. (Remember my mantra, "I'm cheap. I build from
junk!" I woudn't want to stray too far ;~})
I like what you say about buying parts vs. kits. I found a fellow somewhere
in the midwest (name escapes me, but I can look it up if asked) who recycles
good name brand transformers (Stancor, Thordarson, etc.) for very reasonable
prices. Some are NOS and some are perfectly good pulls. And I've twice
filled my bill of materials from Weber for small parts (caps, pots,
resistors, switches, etc.) as his prices for the "one-off" are decent and
the parts appear to be more than adequate, as long as you're not a
cork-sniffer. Kits are an excuse for someone to take a mark-up for doing
all the thinking for you. What's the fun in that? This is the difference
between buying a restored classic car for your collection and buying a
classic car to restore. YMMV.
I also think your advice about making it look like the f-brand or m-brand
(with cloth, tolex, corner hardware, etc.) is right there. I'd go sideways
from your advice. Build the amp as a head. Leave it in the open or fashion
an enclosure of some sort if you like or if you are going to be moving it
around often. Then build or buy one or more speaker cabinet(s) of your
choice. Also, use a multi-tapped output transformer. This will give you
options and choices down the road to mix and match. And, as an aside, don't
be so wedded to having your amp sound exactly like [famous name player] amp.
It won't. Well it might if [famous name player] was playing it.
So, maybe this is more than 2 cents worth. Thanks for sparking the
discussion to a good place.
Phil
PMG
<wheat...@comcast.net> wrote:
>
>"PMG" <xxxx...@comcast.net> wrote in message >
>> I'd rather build an amp in a SF or BF chassis anyhow personally. I
>> appreciate how quickly you can open up a Tweed amp. Much easier than
>> pulling the chassis out in BF & SF amps, but I'd rather have
>> everything laid out all flat, and in the open, instead of the cramped
>> space of a Tweed chassis. I guess you could build a Tweed amp into a
>> SF chassis. I'm sure that would work out.
>>
>
>I have a SF Champ that was gutted and rebuilt with new inerds, and a push,
>pull volume knob. With the volume knob in, it`s a BF Champ, with the volume
>knob pulled out, it`s a Tweed. I love the amp!
I like that idea.
The push/pull knob selects tone stacks?
>I have a BF Super Reverb, BF
>Deluxe Reverb, BF Princeton, and a BF Champ, but the amp that I use around
>the house is the Tweed Clone in the SF chassis.
>
>See ya,
>John
I've been using my BF Bassman a lot these day. A '65. I consider it
a very good era, and this one's got a good sound. Scott seems to love
the sound of his Tweed Champ.
You know, I have enough parts to put together a Tweed Champ clone,
maybe minus a few parts. I don't feel very motivated to build one
though because I don't exactly have a shortage of amps.
PMG
>> "PMG" <xxxx...@comcast.net> wrote in message >
>
>> > I'd rather build an amp in a SF or BF chassis anyhow personally. I
>> > appreciate how quickly you can open up a Tweed amp. Much easier than
>> > pulling the chassis out in BF & SF amps, but I'd rather have
>> > everything laid out all flat, and in the open, instead of the cramped
>> > space of a Tweed chassis.
>
>Why? What difference does it make?
Look at any SF or BF chassis.
Now look at any narrow face Tweed chassis.
The SF/BF chassis is very open, and easy to work in, while the Tweed
chassis is much more closed, which isn't good when you don't see very
well.
In a Tweed chassis, I'd have to find a way to wire almost everything
flat, and then set it into the chassis. I'm sure there's a whole
procedure for dealing with building amps in Tweed chassis, but I'd
rather just build something in a chassis where everything's laid out
flat.
I have a Tweed style Deluxe chassis, but haven't felt like dealing
with building in it.
lbrt...@aol.com
> I LIKE that idea..! ! ! The whole thing could be about 3 inches
> wide... little tiny holes to access the trim pots, keep the alignment
> tool in your pocket. I'd have to have a volume control though...
> maybe make it a real BIG knob... ;-)
You nasty man.
I'd be inclined to stick 'em along a small shielded area at the inside
rear apron of the chassis with small holes for access & provide a
secure clip nearby but out of the way to hold the alignment tool.
Maybe I'd get sexy & slap a HD velcro strip along the holes to cover
'em off with a vinyl-backed little toneau cover to keep shit out of the
chassis (eeek, a piece of Tolex-like material on my amp?). Volume?
Depends. For the last 30 yrs or so I've always kept my amp at what
corresponds to around 7 1/2 on a BF Fender-type front end (i.e., where
it is just getting into breakup on the small & midsize combos), and run
the rest from the axe or even with no control fiddling with just my
fingers. I muffle the amp in smaller situ's, and crank the axe back
for any quieter noodling around. This has worked for me with
everything from the ancient ('52) Tele to my unpotted '59 MM screamer
to my 'bucker Alleykat with a custom jazz wind in one hole & a '57
classic type in the other, but remember I'm a barefoot player relying
on strong hand technique to carry the day and careful touch to keep me
out of trouble. Okay, I still get in trouble once in awhile for a few
measures. :-)
The only other part of this simple system that's important to me, such
as in the case of the 'Kat, is to reduce the axe to having only one Vol
pot that runs it all & is well-placed enough. I have never understood
double (or in the case of Gretsch layouts like the stock Kat, tripple)
Vol's on an axe, I feel it is useless and stupid. I have never
understood the point of using a Vol pot on a 'bucker axe of less than
500k, either (and guys talk about teeny parasitic caps on SF Fender
screens "killing highs"??). The little MM is a special case - its
unpotted p/u has enough highs to shave your eyebrows or empty a club's
front tables with its 250k pot. I have never seen the point in having
linear taper pots on a magnetic p/u guitar, either, I find them useless
& uncontrollable too. My working axe (Kat) is also wired for deep
rhythm (improved from the unpopular pre-'54 Fender attempt and very
useful), and runs piezo mixed onboard. Somehow, all this seems to work
perfectly for me at the same amp control settings in 4 different styles
of music. Maybe I'd better not think about it much, or it won't
anymore, yes? Or maybe I am getting deaf & those people & players
praising me are just feeling sorry for my pitiful efforts to sound
great. I'd better not think about that, either. :-)
The biamped Roland on the floor in my present setup is just set to fill
& fatten up the bottom. I don't think that needs knobs, either. All
they do is give me something to have to screw with for a minute when
they get moved astray in transport. All the CH-60's FX suck and they
stay off.
On the tube amps with springs, I don't think I've moved a 'verb knob
from 2 1/2 since the surf went down in 1965, and my rarely-used trem
has been at the same speed & intensity for almost as long. Maybe I'd
make the trem controls teeny weenie knobs on the rear apron just to be
cute.
I don't need a STBY switch, either. Cathode stripping on a small to
midpower working combo running 450v or less is a joke, a decent quality
power tube will shit the bed or go sour before it makes a significant
difference, necessitating r/r of both, and if someone really HAD to
have protection, a simple internal controlled warmup provision is a
better way. Axes get turned off during breaks.
I don't need a power switch, either, but it's Code-required and
dumb/unsafe to eliminate.
I sure as shit don't need a 'verb footswitch, almost no one does 'verb
on/off in tunes anymore. But a trem switch, however rarely used, is
stupid not to have if there is trem.
So now I am down to one 1/2" & one 3/8" (nominal, they are reamed 1/32
larger) apron hole in the whole chassis, plus maybe those 2 teeny 1/4"
trem pots for the benefit of those who have no emotional security
unless they can control *something*, even if they don't but just know
that it's there. Since there is only one full size and meaningful
control left - the power switch - maybe we should make its hole bigger
and use a keyed switch. How cool would that be? No clutter, just turn
the key to start 'er up & drive 'er, and it looks like you can lock up
something important, with the key only dangling from it when it's on.
Yes, there'd have to be a hidden spare key somewhere, but consider
those jam nights when you go get a cold one before leaving & someone
says: "Ahh, just use Harry's amp, it's right here..." and they proceed
to flail it for an hour and a half while you are waiting to leave.
Anything else we can get rid of?
lbrt...@aol.com
> On 18 Jun 2005 01:37:14 -0700, lbrt...@aol.com wrote:
>
> >> "PMG" <xxxx...@comcast.net> wrote in message >
> >
> >> > I'd rather build an amp in a SF or BF chassis anyhow personally. I
> >> > appreciate how quickly you can open up a Tweed amp. Much easier than
> >> > pulling the chassis out in BF & SF amps, but I'd rather have
> >> > everything laid out all flat, and in the open, instead of the cramped
> >> > space of a Tweed chassis.
> >
> >Why? What difference does it make?
>
> Look at any SF or BF chassis.
Dozens, years. I suppose I should've been clearer & typed that it
doesn't make much difference to me.
> Now look at any narrow face Tweed chassis.
>
> The SF/BF chassis is very open, and easy to work in, while the Tweed
> chassis is much more closed, which isn't good when you don't see very
> well.
Ahh. Good light, good tools, chassis vice... (a chassis vice is not a
bad moral habit, BTW<g>)
> In a Tweed chassis, I'd have to find a way to wire almost everything
> flat, and then set it into the chassis. I'm sure there's a whole
> procedure for dealing with building amps in Tweed chassis, but I'd
> rather just build something in a chassis where everything's laid out
> flat.
Plenty sensible for the casual builder trying to enjoy the experience.
I like a filled-up chassis that has the least practical amount of
wasted real estate that I paid for or fabricated metal to enclose
(within necessary layout & electrical/signal constraints, of course).
It's rarely anything like either of the above. I don't like either one
of 'em & never did, though I have no complaint with either. I like a
chassis that is elegant (i.e., most from the least
materials/parts/space, robust, simple but not simplistic, resonably
merciful for a tech, not owner, to work on). I think both Fender
chassis types you speak of were quite elegant in a different way in
their own time (well-integrated with the whole amp's structure & style
of the day, cheap/easy to make (esp tweed), multifunctional
> I have a Tweed style Deluxe chassis, but haven't felt like dealing
> with building in it.
Makes sense. You'll tear into it one day.
PMG
I love the way on a Tweed amp, you just remove the back panel, any you
have instant access to the insides of the chassis. I have a great
deal of admiration for that.
Just not sure if I'd want to build an amp into one.
Seems to me that Fender's new fake Tweed amps, like the HRD and the
Blues Jr. have a very wide open chassis. If you could find a HRD
chassis or hopelessly damaged amp on Ebay, that it'd be a great
chassis to build an amp into. Never heard of anyone who's done that
though, so maybe there's something I'm missing.
But I'd think there'd be a lot of HRD and Blues Juniors that have had
major meltdowns, so...
>> I have a Tweed style Deluxe chassis, but haven't felt like dealing
>> with building in it.
>
>Makes sense. You'll tear into it one day.
It might become a Champ clone, with a 12" speaker. If I ever get
around to it.
John Wheaton
>
Exactly! If I want to use some toys, I push in the Volume Knob, and I have a
BF Champ, pull it out, and it`s a screaming Tweed!
>
> You know, I have enough parts to put together a Tweed Champ clone,
> maybe minus a few parts. I don't feel very motivated to build one
> though because I don't exactly have a shortage of amps.
>
I have a BF Super Reverb, BF Deluxe Reverb, BF Princeton, and a BF Champ,
but the amp that I use around the house is the Tweed Clone in the SF
chassis, so I can relate to having a few amps kicking around!
See ya,
John
lbrt...@aol.com
yourself. :-)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7331267228&sspagename=ADME%3AB%3ARECO%3AMT%3A2
Phil S
<lbrt...@aol.com> wrote in message
news:1119147418.8...@o13g2000cwo.googlegroups.com...
> Phil, buy this cheap & tell the wife you built it, you'll redeem
> yourself. :-)
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7331267228&sspagename=ADME%3AB%3ARECO%3AMT%3A2
>
LOL! Thanks! Nice clean piece. No copper plating; I dunno.
lbrt...@aol.com
> You and I are far apart on the continuum of expertise. I am a rank ameteur
> who builds low cost random projects from junk for the entertainment value
> and the hope that just maybe I'll like what I build well enough to use it.
> I'm one for two on that score (as so-so Frankenchamp, and a window-shaking
> Franken-5e3) and soon to try a third project. This is no digression from
> the topic, rather to set the stage for a slightly different point of view
> from someone who is not very far ahead of the OP. I know this approach is
> 180 degrees from your recommendation to play the amp before building and to
> select the project you really want.
I well understand all of that and where you're at, Phil. Consider that
you're in a 3rd category entirely, that of salvage-building, fun & also
actually on a rather good & traditional starting path of gaining
increasing building skills. OTOH, the thread and most of the build
inquiries or posts we get here are about folks who are wanting to
create more of a long-desired & more formalized playing tool involving
a more singular and more costly committment. IOW, a convincing
substitute for an expensive new or vintage store-bought amp that will
be treated and used in the same way. These are the people I've sought
to address, because they represent the largest number of those being
courted or inspired by the current building fad. They come in with
doubts, some insecurities, often little or no assembly skills at all,
and preconditioned notions often not in their own best interests. You
know what you can/can't and are/aren't doing, well within the
reasonable limits of what you do/don't know, and your priorities,
dedication and expected results are likewise different. One might say
you are sort of apprenticing yourself via the bootstrap mode, and enjoy
doing so, while most of these folks are somewhat anxious to correctly
choose & construct their dream amp - or if not, at least one that is a
breif dress rehearsal for doing so soon thereafter.
> Kits are an excuse for someone to take a mark-up for doing
> all the thinking for you.
Sure, it's almost like paying someone to rob you (of satisfaction,
decisionmaking and control even moreso than funds). But we do well to
remember that today people have been heavily conditioned to believe
they can't - or maybe shouldn't - act independently nor take control of
anything, let alone take risks on unfamiliar ground.
> Build the amp as a head. Leave it in the open or fashion
> an enclosure of some sort if you like or if you are going to be moving it
> around often. Then build or buy one or more speaker cabinet(s) of your
> choice.
An enclosure is a necessity with safety heading the reasons, but IMO
you have the picture, and for more reasons than you've cited.
PMG
<wheat...@comcast.net> wrote:
>
>"PMG" <xxxx...@comcast.net> wrote in message >
>> The push/pull knob selects tone stacks?
>>
>
>Exactly! If I want to use some toys, I push in the Volume Knob, and I have a
>BF Champ, pull it out, and it`s a screaming Tweed!
A channel switcher Champ!
>> You know, I have enough parts to put together a Tweed Champ clone,
>> maybe minus a few parts. I don't feel very motivated to build one
>> though because I don't exactly have a shortage of amps.
>>
>
>I have a BF Super Reverb, BF Deluxe Reverb, BF Princeton, and a BF Champ,
>but the amp that I use around the house is the Tweed Clone in the SF
>chassis, so I can relate to having a few amps kicking around!
>
>See ya,
>John
They're spares! I could lose a few without it having an effect my day
to day life.
I no longer have any single ended amps though. Put together anyhow.
Ether
<snip>
So...what do you have against cathode-bias? A lot of *very* serious
players use cathode-bias amps. Elvis Costello used either a wide-panel
Deluxe or Pro on his most recent tour. I noticed that The Edge has a
pair of Tweed Deluxes in his current rig (though God knows what's
inside them).
ZZ Top were also plenty serious on their first album. So are loads and
loads of cathode-bias-loving blues players.
--E
Dave Curtis
Dave Curtis
<psymonds...@comcast.net> wrote:
>Frank,
>I'd like to offer my compliments and thanks for a well written, thoughtful,
>and informative article on guitar amp building.
And I'd like to nominate that for "Builder's
Advice Post of the Year"
Good one, Frank. You still interested in those
1620s?
-Dave
lbrt...@aol.com
> So...what do you have against cathode-bias? A lot of *very* serious
> players use cathode-bias amps.
Nothing at all - I spoke against making it an *option*, and opined that
*that* is useless; kindly distinquish, for I know you enjoy remedial
reading. :-)
That said, I'm not alone in having found from a playing standpoint that
when it is provided as a switchable *option*, and thus one is able to
instantly compare it back/forth with fixed operation with all else
identical, it fails to produce a *beneficial* difference and in fact
most often yields a negative one, in the low-to-midpower PP AB category
most often imagined to benefit from it. This is really a separate
subject from any debate (and if you'll recall one raged for quite
awhile in recent years) over the merits of cathode bias (or lack of
same), because using the same load R & other identical ckt parameters
for both schemes in a selectable bias arrg't isn't a fair
representation of how both schemes sound & perform when each is
designed/built for what it is.
Beyond this, it is my *opinion* that cathode bias has been over-hyped
and partially mythologicized in sonic terms as well, but that, too, is
a separate subject and more of a players' discussion than a builders'
one.
Returning to our original one, I'm confident that if you add switchable
c/b to one of your fixed bias PP amps you'll be unimpressed with it.
You can easily prove/disprove it in 1/2 hour with a DPDT & R/C
temporarily slapped in.
Trust clearer, HTH
- f.
Phil S
<lbrt...@aol.com> wrote in message
news:1119153116.0...@g43g2000cwa.googlegroups.com...
Hmmm....I guess I'll have to dig out the router and make some cabinets for
those heads I built. It's a good excuse to buy that dovetail jig I've
always wanted! (Phil's Rule: tool purchases don't count towards the cost of
the project ;~})
And thanks for your comments. I suppose I hadn't really considered what
motivates many people in this kind of endeavor, but surely you are right
there with your thinking.
I also think it is uncanny the way you describe me as engaging in
self-apprenticeship. I really got into it by accident and found it was
interesting stuff. It probably won't surprise you... in 1974-75, I helped a
friend rebuilt his 1951 Ford F-1 engine using the factory service manual and
some occasional advice from a friend. Neither of us had done that kind of
thing before. I recall that I broke the first piston ring as we were
putting it on the piston. I got lucky and found someone to sell us just
that one ring instead of buying another whole set (who had that kind of
$$?). That flathead six is the automotive equivalent of a Fender Champ.
I'm a natural born tinkerer.
Congrats, I think your post is headed for the AGA FAQ, maybe even get it's
own page!
Phil
lbrt...@aol.com
nasties, or invite him to do so in trust<guilty look>. :-)
lbrt...@aol.com
of other things & my primary summer gig got trashed to make things a
little more "interesting", thx ur long patience, lemme know what I may
give you for 'em.
Dave Curtis
wrote:
>If he's going to do this, I'd like to edit out the NG-context salty
>nasties, or invite him to do so in trust<guilty look>. :-)
I didn't see any nasties (glasses probably dirty).
At any rate, good post, Frank.
-Dave
Dave Curtis
wrote:
I've got $16 into the pair, so that would do it.
Got any gigs coming up?
-Dave
lbrt...@aol.com
> I've got $16 into the pair, so that would do it.
I'll email & add a few bucks if you'll USPS 'em, hectic this month,
other stuff I'll tell ya therein.
> Got any gigs coming up?
Down to spotty stuff in NH & functions at the moment; singer decided
with an $80k job didn't want/need $$ for a few hrs of weekend time away
from family anymore. Not unusual these daze. Every gig is temporary,
even if you have it all your life, yes? Next time there's anything
close by I'd be happy to let you know. :-)
Ether
> Ether wrote:
>
> > So...what do you have against cathode-bias? A lot of *very* serious
> > players use cathode-bias amps.
>
> Nothing at all - I spoke against making it an *option*, and opined that
> *that* is useless; kindly distinquish, for I know you enjoy remedial
> reading. :-)
You said:
"cathode bias is an utterly useless option in a PP AB1 guitar amp for
serious playing."
>From what you said, I inferred that you don't care for cathode-bias,
option or stock standard. My question flowed logically from that.
Maybe you should join my class--though if the enrollment gets going up,
I'm going to start charging. (Remedial writing might help, too.)
> That said, I'm not alone in having found from a playing standpoint that
> when it is provided as a switchable *option*, and thus one is able to
> instantly compare it back/forth with fixed operation with all else
> identical, it fails to produce a *beneficial* difference and in fact
> most often yields a negative one, in the low-to-midpower PP AB category
> most often imagined to benefit from it.
Ok--that's a little clearer. (Though I *still* gather that you have
something against cathode-bias.)
> This is really a separate
> subject from any debate (and if you'll recall one raged for quite
> awhile in recent years) over the merits of cathode bias (or lack of
> same), because using the same load R & other identical ckt parameters
> for both schemes in a selectable bias arrg't isn't a fair
> representation of how both schemes sound & perform when each is
> designed/built for what it is.
>
> Beyond this, it is my *opinion* that cathode bias has been over-hyped
> and partially mythologicized in sonic terms as well,
Certain amps were designed around cathode-biased finals, and they sound
great that way--like the Tweed Deluxe. (In fact, I keep reading that
most who install a cathode/fixed-bias switch in a 5E3 finally decide to
keep it stock.)
Both have their merits, and obviously there are great amps in both
categories.
> but that, too, is a separate subject and more of a players'
> discussion than a builders' one.
Amps are useless unless played! It's the sound that matters, not the
way the schematic looks.
> Returning to our original one, I'm confident that if you add switchable
> c/b to one of your fixed bias PP amps you'll be unimpressed with it.
> You can easily prove/disprove it in 1/2 hour with a DPDT & R/C
> temporarily slapped in.
Yeah, but it's the design of the *whole* amp that matters. As you
imply, a BF Deluxe Reverb may not sound better with cathode bias. By
the same token, a Tweed Deluxe may not sound any better with fixed
bias. The two amps don't sound that much alike, and each is great for a
different purpose.
Great musicans use amps of both types.
> Trust clearer, HTH
> - f.
Yep. Just don't go dissin' those cathodes!
By the way--have you ever played a 5E3 or 5E5?
--E
lbrt...@aol.com
> You said:
>
> "cathode bias is an utterly useless option in a PP AB1 guitar amp for
> serious playing."
...ahhh...he can read...
> >From what you said, I inferred that you don't care for cathode-bias,
> option or stock standard. My question flowed logically from that.
...no, he can't...
> Maybe you should join my class--though if the enrollment gets going up,
> I'm going to start charging. (Remedial writing might help, too.)
...projection...where's the DSM-IV when we need it...
> > That said, I'm not alone in having found from a playing standpoint that
> > when it is provided as a switchable *option*, and thus one is able to
> > instantly compare it back/forth with fixed operation with all else
> > identical, it fails to produce a *beneficial* difference and in fact
> > most often yields a negative one, in the low-to-midpower PP AB category
> > most often imagined to benefit from it.
>
> Ok--that's a little clearer. (Though I *still* gather that you have
> something against cathode-bias.)
...he's not gonna give up trying to instigate yet another cathode bias
debate...resist de bait...put de lime in de coconut...
> Certain amps were designed around cathode-biased finals, and they sound
> great that way--like the Tweed Deluxe.
...designed "around"...how imaginative...lower Eo ckt straight out of
de toob manual...
> (In fact, I keep reading that
> most who install a cathode/fixed-bias switch in a 5E3 finally decide to
> keep it stock.)
...we wonder why old crude low Eo amp and matching iron not sound so
good with bias ckt that sound good on much higher operating curve, beeg
misterie...put de lime in de coconut....
> Both have their merits, and obviously there are great amps in both
> categories.
...when nothing to say, make plattitude...pass de lime...
> Amps are useless unless played! It's the sound that matters, not the
> way the schematic looks.
...novel idea, me never know this...more cocomut...
> <pen knife> As you
> imply, a BF Deluxe Reverb may not sound better with cathode bias. By
> the same token, a Tweed Deluxe may not sound any better with fixed
> bias. The two amps don't sound that much alike, and each is great for a
> different purpose.
...me say this in beeginneeng, whatdafuk happen to de lime...
> Great musicans use amps of both types.
...maybe he mean they bisexual...most great musician I know only use
one amp at time...coconut...
> Yep. Just don't go dissin' those cathodes!
...no taka de bait...passa de lime agin...
> By the way--have you ever played a 5E3 or 5E5?
... no, mice not like cheese, cat not have ass, wild bear never shit in
woods...only played thru empty carboard boxes with line cords in
fifties, all make-believe...very Etherial...put de lime in de
coconut...
...take two...and call me in the morning...
Ether
lbrt...@aol.com blabbed endlessly, as usual:
> Ether bifurcated passionately:
>
> > You said:
> >
> > "cathode bias is an utterly useless option in a PP AB1 guitar amp for
> > serious playing."
>
> ...ahhh...he can read...
Better than you, apparently.
>
> > >From what you said, I inferred that you don't care for cathode-bias,
> > option or stock standard. My question flowed logically from that.
>
> ...no, he can't...
Frank, you have no grasp of communication. Or logic. (Now that we've
covered that, the impetus behind a lot of your rambling, saying-nothing
posts becomes clear!)
> > Maybe you should join my class--though if the enrollment gets going up,
> > I'm going to start charging. (Remedial writing might help, too.)
>
> ...projection...where's the DSM-IV when we need it...
I'm sure your psychologist has one. Ask him during your next office
visit.
<snippage o'drivel, classic Frankie style>
> > > Beyond this, it is my *opinion* that cathode bias has been
> > > over-hyped and partially mythologicized in sonic terms as well,
> > > but that, too, is a separate subject and more of a players'
> > > discussion than a builders' one.
> >
> > Amps are useless unless played! It's the sound that matters, not the
> > way the schematic looks.
>
> ...novel idea, me never know this...more cocomut...
Apparently, you didn't. (See your comment above.)
>
> > <pen knife> As you
> > imply, a BF Deluxe Reverb may not sound better with cathode bias. By
> > the same token, a Tweed Deluxe may not sound any better with fixed
> > bias. The two amps don't sound that much alike, and each is great for a
> > different purpose.
>
> ...me say this in beeginneeng, whatdafuk happen to de lime...
>
> > Great musicans use amps of both types.
>
> ...maybe he mean they bisexual...most great musician I know only use
> one amp at time...coconut...
Some great players use only one amp at a time. LOTS of other great
players use one amp for clean, and another for lead tones. Ever see
Eric Johnson play? (You should get out more--maybe you'd have something
more informed to say on the subject.)
> > > Trust clearer, HTH
> > > - f.
> >
> > Yep. Just don't go dissin' those cathodes!
>
> ...no taka de bait...passa de lime agin...
>
> > By the way--have you ever played a 5E3 or 5E5?
>
> ... no, mice not like cheese, cat not have ass, wild bear never shit in
> woods...only played thru empty carboard boxes with line cords in
> fifties, all make-believe...very Etherial...put de lime in de
> coconut...
Ah--that explains it. You don't know what the fuck you're talking
about.
> ...take two...and call me in the morning...
Get back to me when you've actually been in the same room with a Tweed
Deluxe (5E3) and/or Tweed Pro (5E5)--and have maybe played an actual
guitar through one or both.
Then we'll talk.
In the meantime, Frankie--more thought, less coconut!
--E
Stephen Cowell
hanging around here, let me translate...
Designing an amp to do both cathode
and fixed bias results in two different
and mutually exclusive optimizations
that don't overlap. Neither is optimum.
Easy enough?
__
Steve
.
Walter Campbell
"Stephen Cowell" <sco...@sbcglobal.net> wrote:
> Steve
> .
And therefore will sound terrible, like the Carr Slant 6, eh...
<G>
BTW the Slant 6 does both (at the same time if you want) and is a great
sounding amp in any mode....
Walt Campbell
Campbell Sound
http://www.campbellsound.com/
Stephen Cowell
"Walter Campbell" <wa...@campbellsound.com> wrote in message news:waltc-1A6D74....@corp.supernews.com...
It is not optimum.
__
Steve
.
lbrt...@aol.com
Ya think he'll get it???
(adjusts loincloth & featherband, decides not to grab tomahawk over
being characterized as never playing amps I grew up gigging with)
Ether
In what way?
Have you ever tried a Carr Slant 6? (I haven't; but with enough
ingenuity, I'm sure you could make a banana-biased amp sound good.
Maybe coconut, too, Frank.) It looks to be a fairly nice combination:
http://www.carramps.com/carrslant.html
--E
Ether
> Since Frank's gone native so bad from
> hanging around here, let me translate...
"Mistah Kurtz...he dead."
>
> Designing an amp to do both cathode
> and fixed bias results in two different
> and mutually exclusive optimizations
> that don't overlap. Neither is optimum.
>
> Easy enough?
> __
> Steve
>.
That may have been what he meant; it's not what he said. (Or not all of
it.)
To wit: (Lbrty4Us wrote...)
>>> Beyond this, it is my *opinion* that cathode bias has
>>> been over-hyped and partially mythologicized in sonic
>>> terms as well, but that, too, is a separate subject and
>>> more of a players' discussion than a builders' one.
Maybe the sound of cathode-bias has been "mythologized" (though I did
enjoy Frank's inventive native spelling). Still, there are a lot of
cathode-biased amps that sound absolutely kick-ass. Partially because
of the way they are biased,too--and as Frank apparently admits,
switching an amp like a 5E3 to fixed-bias yields no improvement in
tone.
Anyway, the dual-biased Carr Slant 6V might just prove Frank dead
wrong, regardless of what he meant. Guess that's why he doesn't have
his own amp company!
Regards,
--E
Stephen Cowell
"Ether" <et...@x-mail.net> wrote in message news:1119493445.4...@o13g2000cwo.googlegroups.com...
I'd love to try one... my point is, after you've already
got the higher voltage and bias setup going, the iron
will have to be compromised for either cathode bias
(pulls DC like classA) or fixed (doesn't have to carry
constant DC magnetizing current). The OT's are two
different designs... at different places on the load line
the design impedance changes as well. Compromises
are compromises... fully tweaked designs aren't
compromised.
__
Steve
.
lbrt...@aol.com
> I'd love to try one... my point is, after you've already
> got the higher voltage and bias setup going, the iron
> will have to be compromised for either cathode bias
> (pulls DC like classA) or fixed (doesn't have to carry
> constant DC magnetizing current). The OT's are two
> different designs... at different places on the load line
> the design impedance changes as well. Compromises
> are compromises... fully tweaked designs aren't
> compromised.
Why bother, Steve? May as well let the boy & his marbles alone, he's
number than a hake & has more emotional & projection problems than a
menopausal woman in a lifeboat...probably hasn't had a gig since the
last band he was kicked out of 10 years ago...not a happy camper.
Stephen Cowell
<lbrt...@aol.com> wrote in message news:1119499837....@f14g2000cwb.googlegroups.com...
Frank, Frank.... you *have* gone native. Enough with
the ad hominem... we've all been stung at one point or
another. Save it for the political threads!
__
Steve
.
Ether
lbrt...@aol.com wrote:
> Stephen Cowell wrote:
>
> > I'd love to try one... my point is, after you've already
> > got the higher voltage and bias setup going, the iron
> > will have to be compromised for either cathode bias
> > (pulls DC like classA) or fixed (doesn't have to carry
> > constant DC magnetizing current). The OT's are two
> > different designs... at different places on the load line
> > the design impedance changes as well. Compromises
> > are compromises... fully tweaked designs aren't
> > compromised.
>
> Why bother, Steve? May as well let the boy & his marbles alone, he's
> number than a hake & has more emotional & projection problems than a
> menopausal woman in a lifeboat...
Is that what your analyst told you, Frank? Poor boy. You must spend a
lot of time in therapy--it's all you talk about.
> probably hasn't had a gig since the last band he was kicked
> out of 10 years ago...not a happy camper.
I've never been kicked out of a band, actually. Plenty happy, too. Must
be you "projecting" again, Frank! Tsk, tsk.
--E
P.S. Damn, this is fun!
Ether
Ok.
> The OT's are two different designs... at different
> places on the load line the design impedance changes as well.
Is the OT of a Tweed Deluxe that much different than a Deluxe Reverb
OT? (Other than the latter producing better bass.) They're about the
same size/weight (more or less), and the turns ratio is the same. How
would a compromise on the OT affect the sound & operation in such a
case?
> Compromises are compromises... fully tweaked designs aren't
> compromised.
Right. What I'm saying is that there's a design solution that will cope
with pretty much any obstacle--bias switching among them. Carr seems to
have found it. (And listen to the sound samples on their website--very
nice.) Might even be useful for "serious playing"!
Regards,
--E
Ether
Ah, don't worry--I can take it. Frank's just still miffed at the
shocking and inexplicable existence of AC wall warts. He'll get over
it.
Now, his personality disorder--that may not be so easy to overcome!
--E
Walter Campbell
"Stephen Cowell" <sco...@sbcglobal.net> wrote:
> > > >
> > > > BTW the Slant 6 does both (at the same time if you want) and is a great
> > > > sounding amp in any mode....
> > >
> > > It is not optimum.
> >
> >
> > In what way?
> >
> > Have you ever tried a Carr Slant 6? (I haven't; but with enough
> > ingenuity, I'm sure you could make a banana-biased amp sound good.
> > Maybe coconut, too, Frank.) It looks to be a fairly nice combination:
>
> I'd love to try one... my point is, after you've already
> got the higher voltage and bias setup going, the iron
> will have to be compromised for either cathode bias
> (pulls DC like classA) or fixed (doesn't have to carry
> constant DC magnetizing current). The OT's are two
> different designs... at different places on the load line
> the design impedance changes as well. Compromises
> are compromises... fully tweaked designs aren't
> compromised.
>
> Steve
> .
steve,
this is starting to sound like a HiFi issue to me. It's clear that some
of the best sounding guitar amps of all time weren't "optimized" and
were frequently "compromised" in one way or another (in many ways for
some of them) yet the end result worked (as does the Slant 6v BTW).
Porky
Agreed, minimal caustic nasties in this piece and a great deal of
truth. I've been off-line for 2 weeks, float camp, and was happy to
stumble upon this, thanx Frank.
One reBUTTal I must express, the practice of assembling the entire
circuit mechanically. This entails wrapping and crimping all the leads
tight to the terminals. Okay for a one-time fixed assembly, like ham
gear, butt...
If you plan to tweak the performance of the amp once it is up and
humming, use a short hook on those component leads that can be removed
without damaging the terminal. And that involves soldering all the
leads to that terminal, before moving on.
Porky
Stephen Cowell
"Ether" <et...@x-mail.net> wrote in message news:1119542736.4...@g14g2000cwa.googlegroups.com...
>
>
> Stephen Cowell wrote:
...
> > The OT's are two different designs... at different
> > places on the load line the design impedance changes as well.
>
> Is the OT of a Tweed Deluxe that much different than a Deluxe Reverb
> OT? (Other than the latter producing better bass.) They're about the
> same size/weight (more or less), and the turns ratio is the same. How
> would a compromise on the OT affect the sound & operation in such a
> case?
Obviously, the part numbers are different... the transformers are
the same size, yet have different turns ratios. The Tweed is
operating at a lower point on the load line.. it runs around 6000ohms
where the BF runs nearer 4000. Running one transformer
with two different primary impedances into one secondary
impedance is non-optimum... bandwidth or power is
sacrificed.
> > Compromises are compromises... fully tweaked designs aren't
> > compromised.
>
> Right. What I'm saying is that there's a design solution that will cope
> with pretty much any obstacle--bias switching among them. Carr seems to
> have found it. (And listen to the sound samples on their website--very
> nice.) Might even be useful for "serious playing"!
For me, the proof is in the playing.. sound samples can
fool you. I'd be interested to play one, were it available
locally.
__
Steve
.
Stephen Cowell
"Walter Campbell" <wa...@campbellsound.com> wrote in message news:waltc-673C17....@corp.supernews.com...
...
> this is starting to sound like a HiFi issue to me. It's clear that some
> of the best sounding guitar amps of all time weren't "optimized" and
> were frequently "compromised" in one way or another (in many ways for
> some of them) yet the end result worked (as does the Slant 6v BTW).
'Worked' is in the ear of the player... like I said, I'd be
interested to play one, but I can't think of a good reason
to do both with one amp... that would preclude having
two amps, and the more amps, the better!
__
Steve
.
Ether
Stephen Cowell wrote:
> "Ether" <et...@x-mail.net> wrote in message news:1119542736.4...@g14g2000cwa.googlegroups.com...
> >
> >
> > Stephen Cowell wrote:
>
> ...
>
> > > The OT's are two different designs... at different
> > > places on the load line the design impedance changes as well.
> >
> > Is the OT of a Tweed Deluxe that much different than a Deluxe Reverb
> > OT? (Other than the latter producing better bass.) They're about the
> > same size/weight (more or less), and the turns ratio is the same. How
> > would a compromise on the OT affect the sound & operation in such a
> > case?
>
> Obviously, the part numbers are different...
I've never actually *seen* a Tweed Deluxe OT part number referenced by
anyone other than Mercury Magnetics and Mojo. What was the Fender part
number for the 5E3 OT?
> the transformers are the same size, yet have different turns ratios.
Are you sure? What is the turns ratio on an original 5E3 OT? (Have you
actually measured one yourself? Just interested, if you have.)
The Mojo Tweed Deluxe OT gives a primary impedance of 8000 ohms. With
the standard 8 ohm speaker load, that works out to a turns ratio of
31.6. That's *exactly* the same turns ratio I measured a on a stock
Deluxe Reverb OT. (I've never had my hands on an original Tweed Deluxe
OT.)
Then again, I don't exactly trust the accuracy of Mojotone's posted
specs.
> The Tweed is operating at a lower point on the load line.. it runs around 6000ohms
> where the BF runs nearer 4000. Running one transformer
> with two different primary impedances into one secondary
> impedance is non-optimum... bandwidth or power is
> sacrificed.
Right--if that's what's really happening.
>
> > > Compromises are compromises... fully tweaked designs aren't
> > > compromised.
> >
> > Right. What I'm saying is that there's a design solution that will cope
> > with pretty much any obstacle--bias switching among them. Carr seems to
> > have found it. (And listen to the sound samples on their website--very
> > nice.) Might even be useful for "serious playing"!
>
> For me, the proof is in the playing.. sound samples can
> fool you. I'd be interested to play one, were it available
> locally.
True. But if the sound samples suck, you can be fairly sure the amp
will also suck in person.
I'll keep an eye out for Carr at the next guitar show I attend.
--E
Stephen Cowell
"Ether" <et...@x-mail.net> wrote in message news:1119593677.7...@g44g2000cwa.googlegroups.com...
>
> Stephen Cowell wrote:
> > "Ether" <et...@x-mail.net> wrote in message news:1119542736.4...@g14g2000cwa.googlegroups.com...
> > >
> > >
> > > Stephen Cowell wrote:
> >
> > ...
> >
> > > > The OT's are two different designs... at different
> > > > places on the load line the design impedance changes as well.
> > >
> > > Is the OT of a Tweed Deluxe that much different than a Deluxe Reverb
> > > OT? (Other than the latter producing better bass.) They're about the
> > > same size/weight (more or less), and the turns ratio is the same. How
> > > would a compromise on the OT affect the sound & operation in such a
> > > case?
> >
> > Obviously, the part numbers are different...
>
> I've never actually *seen* a Tweed Deluxe OT part number referenced by
> anyone other than Mercury Magnetics and Mojo. What was the Fender part
> number for the 5E3 OT?
There's not one... if it was a direct cross for the BF
part, you'd see it in the parts list, I'm guessing.
>
> > the transformers are the same size, yet have different turns ratios.
>
> Are you sure? What is the turns ratio on an original 5E3 OT? (Have you
> actually measured one yourself? Just interested, if you have.)
No...
> The Mojo Tweed Deluxe OT gives a primary impedance of 8000 ohms. With
> the standard 8 ohm speaker load, that works out to a turns ratio of
> 31.6. That's *exactly* the same turns ratio I measured a on a stock
> Deluxe Reverb OT. (I've never had my hands on an original Tweed Deluxe
> OT.)
Neither have I.
> Then again, I don't exactly trust the accuracy of Mojotone's posted
> specs.
I'd imagine that their ratio and impedance specs
are OK... but they're not close to the design
impedances of the original parts. 'Close enough'
is what we're dealing with here... I need to give
the cite for the impedance values I cited:
http://www.harpamps.com/transformers.html
" Fender Tweed type amps are supposed to have about 6500 ohms with an 8 ohm load. Fender black face amps have an impedance of 4300 at 8 ohms "
The data is not easy to find!
> > The Tweed is operating at a lower point on the load line.. it runs around 6000ohms
> > where the BF runs nearer 4000. Running one transformer
> > with two different primary impedances into one secondary
> > impedance is non-optimum... bandwidth or power is
> > sacrificed.
>
> Right--if that's what's really happening.
It's a fact that different P-K voltages result in
different points on the LL... resulting in different
optimum load impedances.
> > > > Compromises are compromises... fully tweaked designs aren't
> > > > compromised.
> > >
> > > Right. What I'm saying is that there's a design solution that will cope
> > > with pretty much any obstacle--bias switching among them. Carr seems to
> > > have found it. (And listen to the sound samples on their website--very
> > > nice.) Might even be useful for "serious playing"!
> >
> > For me, the proof is in the playing.. sound samples can
> > fool you. I'd be interested to play one, were it available
> > locally.
>
> True. But if the sound samples suck, you can be fairly sure the amp
> will also suck in person.
Not entirely proven... I'd have to twiddle
the knobs. Beware of TV salesmen!
>
> I'll keep an eye out for Carr at the next guitar show I attend.
Me, too...
__
Steve
.
Walter Campbell
"Stephen Cowell" <sco...@sbcglobal.net> wrote:
> Steve
> .
can't (unfortunately for my bank account) argue with that!
Ether
Stephen Cowell wrote:
> "Ether" <et...@x-mail.net> wrote in message news:1119593677.7...@g44g2000cwa.googlegroups.com...
> >
> > Stephen Cowell wrote:
> > > "Ether" <et...@x-mail.net> wrote in message news:1119542736.4...@g14g2000cwa.googlegroups.com...
> > > >
> > > >
> > > > Stephen Cowell wrote:
> > >
> > > ...
> > >
> > > > > The OT's are two different designs... at different
> > > > > places on the load line the design impedance changes as well.
> > > >
> > > > Is the OT of a Tweed Deluxe that much different than a Deluxe Reverb
> > > > OT? (Other than the latter producing better bass.) They're about the
> > > > same size/weight (more or less), and the turns ratio is the same. How
> > > > would a compromise on the OT affect the sound & operation in such a
> > > > case?
> > >
> > > Obviously, the part numbers are different...
> >
> > I've never actually *seen* a Tweed Deluxe OT part number referenced by
> > anyone other than Mercury Magnetics and Mojo. What was the Fender part
> > number for the 5E3 OT?
>
> There's not one... if it was a direct cross for the BF
> part, you'd see it in the parts list, I'm guessing.
I'm sure it's not exactly the same part. I'm just not convinced that
the turns ratio wasn't the same. (And maybe Fender didn't have a
specific part number for the Tweed Deluxe OT back in the '50s. Though
the Triad transformers used in the tweeds ceratinly had part numbers.
Wonder who made the 5C3, 5D3, and 5E3 OTs.)
>
> >
> > > the transformers are the same size, yet have different turns ratios.
> >
> > Are you sure? What is the turns ratio on an original 5E3 OT? (Have you
> > actually measured one yourself? Just interested, if you have.)
>
> No...
Nobody seems to have seen one of these. I posted a question about this
some time ago, and there was no answer.
>
> > The Mojo Tweed Deluxe OT gives a primary impedance of 8000 ohms. With
> > the standard 8 ohm speaker load, that works out to a turns ratio of
> > 31.6. That's *exactly* the same turns ratio I measured a on a stock
> > Deluxe Reverb OT. (I've never had my hands on an original Tweed Deluxe
> > OT.)
>
> Neither have I.
Anybody out there who can chime in with hands-on experience? (Or take
your '59 Tweed Deluixe OT out and measure the turns ratio? Actually, if
you pull the output tubes and speaker plug, this could be done without
removing the transformer.)
>
> > Then again, I don't exactly trust the accuracy of Mojotone's posted
> > specs.
>
> I'd imagine that their ratio and impedance specs
> are OK... but they're not close to the design
> impedances of the original parts. 'Close enough'
> is what we're dealing with here... I need to give
> the cite for the impedance values I cited:
>
> http://www.harpamps.com/transformers.html
>
> " Fender Tweed type amps are supposed to have about 6500 ohms with an 8 ohm load. Fender black face amps have an impedance of 4300 at 8 ohms "
Aha! The key phrase is "supposed to". The statement doesn't seem to be
based on actual direct observation.
> The data is not easy to find!
No kidding. There's absolutely nothing on the internet about tweed OT
turns ratios. Sounds like a good project for you techs who have tweeds
come across your bench with some regularity.
>
> > > The Tweed is operating at a lower point on the load line.. it runs around 6000ohms
> > > where the BF runs nearer 4000. Running one transformer
> > > with two different primary impedances into one secondary
> > > impedance is non-optimum... bandwidth or power is
> > > sacrificed.
> >
> > Right--if that's what's really happening.
>
> It's a fact that different P-K voltages result in
> different points on the LL... resulting in different
> optimum load impedances.
That I understand.
Correct me if I'm wrong, but I'm under the impression that the output
transformer just reflects the load of the speaker back onto the plates.
So, take the case of the Tweed Deluxe and the Blackface Deluxe Reverb
OTs, and assume for the sake of argument that the turns ratios are the
same. The impedance ratio is the square of the turns ratio; so if the
turns ratio (actually measured on a SF DR OT) is 31.7, the impedance
ratio is 1000. That makes the plate load 8000 Ohms with the typical
8-Ohm speaker.
(Correct so far?)
Now, if the Deluxe Reverb circuit is really calling for a 4300-ohm
plate load, presenting the output tube plates with an 8000-Ohm load is
going to limit the power, and will be, as you say, not optimal.
I just don't believe that's the case. It seems to me that the DR is
designed with an expected 8000-ohm plate load, which is typical of a
6V6GT in class AB1 operation. (Tell me if I'm missing something.)
>
> > > > > Compromises are compromises... fully tweaked designs aren't
> > > > > compromised.
> > > >
> > > > Right. What I'm saying is that there's a design solution that will cope
> > > > with pretty much any obstacle--bias switching among them. Carr seems to
> > > > have found it. (And listen to the sound samples on their website--very
> > > > nice.) Might even be useful for "serious playing"!
> > >
> > > For me, the proof is in the playing.. sound samples can
> > > fool you. I'd be interested to play one, were it available
> > > locally.
> >
> > True. But if the sound samples suck, you can be fairly sure the amp
> > will also suck in person.
>
> Not entirely proven... I'd have to twiddle
> the knobs. Beware of TV salesmen!
There's nothing I've ever seen on TV that appeared to be crap, that was
actually better in person! (Usually, it's the other way around.)
>
> >
> > I'll keep an eye out for Carr at the next guitar show I attend.
>
> Me, too...
> __
> Steve
> .
Regards,
--E
Stephen Cowell
"Ether" <et...@x-mail.net> wrote in message news:1119636967....@g43g2000cwa.googlegroups.com...
...
> I just don't believe that's the case. It seems to me that the DR is
> designed with an expected 8000-ohm plate load, which is typical of a
> 6V6GT in class AB1 operation. (Tell me if I'm missing something.)
That impedance depends on PK voltage... the class doesn't come
into that part of it, IIRC.
__
Steve
.