Sovtek MiG 50H "the Tube Midget"
David A. Morning
> : >>>>>: The amp is FAR better than Marshall in every way.
> : >>>>>: When you put the two up against each other in a side-by-side test,
> : >>>>>: SOVTEK always wins - at a fraction of their price.
>
> : I find these last statements a little brash, especially from
someone
>
> Sometimes the truth hurts . . .
Well that's rather a matter of opinion, isn't it? and given your own
connections with Sovtek, should be taken with a healthy dose of salt!
> : This is the equivalent of saying "Brand X rules... Brand Y
sucks", and
> : doesn't carry much weight on this newsgroup.
>
> This is a three part subject:
> 1) My opinion
> 2) Technical facts
> 3) Other opinions
>
> My opinion: The 50H and the 100H have a full/warm sound very much like a
> hot-rodded JMP series Marshall.
JMP is the Marshall midi pre-amp range - JMP1 still being the current
version.
> I get lotsa crunch when I need it and
> they clean up nicely. Good low freq, tons of sweet harmonics. Every 900
> series Marshall I ever played sounded like a buzzy tin can
JCM900 series is aimed primarily at the heavy metal market, lots of heavy
overdrive, to this end it uses a diode clamp at the front end.
. . . really
> thin and hard sounding, I never managed to get any useable sounds out of
> any of them. Good for Metallica, not for me.
...which is precisely the market the JCM900 targets.
> The 800 series were better, but
> still thin and buzzy. If you changed a few things they were ok.
JCM800 comes in innumerable shapes and forms. Some have, like the JCM900,
have diode clamps fitted, others do not. The topology of each, a key element
in getting the characteristic sound from an amp, also varies widely
throughout the range. JCM800s sound quite different across the range. Models
1987 and 1959 have a traditional Super Lead/Bluesbreaker Topology, 2103, 2203,
2104 and 2204 have a higher gain version (extra gain stage). All the above
use cathode followers to drive the tone control. The 2000 series is a split
channel version with 3 gain stages, the third driving the tone control as
a common cathode. The tone control structure differs between the channels with
one channel fitted with a mid 'sweep' control. The 4140 is a lowish gain (for
Marshall) amp with only two gain stages pre-tone control per channel much
much higher post tone control gain. The 4210 is, again, a split channel amp
but one channel is fitted with a diode clamp circuit for distortion.
How one can generalise such a wide range of amps and dismiss them all as
'thin and buzzy'?It implies to me a lack of knowledge of these amps.
>But the 900
> is Marshall's cream piece right now.
No its not. The 900 is a niche market aimed at heavy metal players. Main amp is
still the 6100 series Anniversary, or rather its updated version, and the JTM
Blues amps. It's biggest seller is the Valvestate8080 combo, but not relevant
here as it is a hybrid.
> Technical facts: Look inside a 900, them look inside a MIG-100H or 50H.
> Which one is hand wired?
Is this supposed to mean anything? I had an old 1959 Super Lead Mk1 which
was hand wired. It was the worst sounding, most unreliable amp I ever played
"Hand wiring' is just marketing hype.
>Which one is built with military grade parts?
This is *Soviet* standard mil grade? I recall purchasing Soviet mil. grade
metal film resistors some years back. They were worse than the commercial
carbon versions available at my local electronics store and I had to spend a
considerable amount of time going through them selecting. One third of them
failed to even meet the stated tolerance standard.
Just because it says 'mil grade' doesn't mean its top quality. I'd put a
Mullard 'nos' EL34 up against any of these Sovtek mil grade EL34s anyday -
if I could afford the Mullard!
> Which one is loaded with extra crap waiting to fail?
What's this supposed to mean? I thought this was the technical section?
> Which one uses the
> cheapest parts/construction but caries the bigger price tag? You tell me.
The SOVTEK? I don't know, but if the implication is longevity, there's still
plenty Super Leads around doing the biz for there owners, SOVTEKS haven't
been around long enough to judge but from what I've read in other related
groups, the reliability of the original Mig 50s, 60s and 100s isn't all that
great
> Other opinions: I could list in detail how many people doubt they
> could get a tone out of anything but Marshall, plug into the SOVTEK as a
> goof, and then ask "where can I get one?" (often before knowing the
> price.) But the gist is - lots of pros and average Joes like amps, if you
> really want the list, I'll post it. The thing is this . . . you tell me.
> Don't listen to me or anyone else. Try it out. Go to a store that caries
> SOVTEK amps, try one. (I don't really like the old MIG-100, so leave that
> one out of the contest.)
I tried an old Mig50 and didn't like it but then, its just a fairly basic
amp so I shouldn't have expected much after having played a Hiwatt. My own
opinion was that it was kinda muddy and lacked 'zing'. Didn't try the others,
so I couldn't say.
> I'm not "fed up" . . . spend your money the way you want. But part of my
> job is to give YOU the option of buying a great amp at a lower price
> before you get slammed by salesmen or swayed by a name.
The 'honest salesman' eh? Come off it!
> There are few
> amps in this price range that sound this good, are this reliable, and
> have the tech support you get with ours. This gives me a sense of
> satisfaction. I'm a musician first - job worker second. I know what it's
> like to need good gear and not have enough $$$ to get something decent. I
> also know what it's like to spend all my $$$ on a name, get it home and
> feel disapointed. This is a factor to me and the other guys at the shop.
It may well be that SOVTEKs do offer a way into cheap amps for the hard up
player, and they, SOVTEK, should be applauded for that, but I think we can
do without the sales hyperbole comparing it with a modern Marshall!
> guest . . . walk into Manny's and take "one of everything please!" I own a
> Marshall, I love it. It's an early JTM-45. At $3000, it had better do
> something that my $450 Midget doesn't.
Well, that's an antique your comparing with now. Times have moved on somewhat.
If it's blues your after, a JTM 30 combo series covers that base, is channel
switching and costs about a third more than a SOVETEK Mig60 head only here
(300 pounds vs 400 pounds) Once you add in a decent cabinet with Celestions
for the SovTek, your right up there in the same price bracket as the Marshall.
Greg House
> > My opinion: The 50H and the 100H have a full/warm sound very much like a
> > hot-rodded JMP series Marshall.
>
> JMP is the Marshall midi pre-amp range - JMP1 still being the current
> version.
The JMP-1 is a MIDI controlled preamp produced in the last few years.
There was a JMP amp series back in the 70s (made until sometime in the
very early 80s). That's what he was talking about.
Came after the JTMs and Supers, but before the JCM800s. I believe they
came in both MV models and non-MV models. I have a JMP 50wt Lead head
myself.
Greg
Scott Farley
jobs on my amps. I live in Salt Lake, and he lives in a little town
Called Logan, but he is a Sovtek dealer also, and his prices are crazy low
as I recall. Though I don't own a Sovtek amp, since I play bass. He
also does great little booster boxes, and very smart
rods on classic amps for cheap. And he will deal by mail
His name is Carl Hart (801)563-8624.
Just some advice about a source that has been very good to me.
So take it as you will.
Scott Farley
(Greg....@Symbios.com)
wrote: : d...@dcs.gla.ac.uk (David A. Morning) wrote:
: > > My opinion: The 50H and the 100H have a full/warm sound very much like a
: > > hot-rodded JMP series Marshall.
: >
: > JMP is the Marshall midi pre-amp range - JMP1 still being the current
: > version.
: The JMP-1 is a MIDI controlled preamp produced in the last few years.
: There was a JMP amp series back in the 70s (made until sometime in the
: very early 80s). That's what he was talking about.
: Came after the JTMs and Supers, but before the JCM800s. I believe they
: came in both MV models and non-MV models. I have a JMP 50wt Lead head
: myself.
: Greg
--
--------------------------------------------
Scott Farley, MFA English, Asst. Lib--Eccles
E-mail: sf0...@u.cc.utah.edu
--------------------------------------------
David A. Morning
<Greg....@Symbios.com> wrote:
> d...@dcs.gla.ac.uk (David A. Morning) wrote:
>
> > > My opinion: The 50H and the 100H have a full/warm sound very much like a
> > > hot-rodded JMP series Marshall.
> >
> > JMP is the Marshall midi pre-amp range - JMP1 still being the current
> > version.
>
> The JMP-1 is a MIDI controlled preamp produced in the last few years.
> There was a JMP amp series back in the 70s (made until sometime in the
> very early 80s). That's what he was talking about.
Fair enough. I'd assumed he was referring to current models since he
aludes elsewhere to the current JCM900 range.
Jack A. Zucker
>
>In article <3vgi5o$5...@interport.net>, e...@interport.net (Elan Portnoy) wrote:
>
>> My opinion: The 50H and the 100H have a full/warm sound very much like a
>> hot-rodded JMP series Marshall.
>
>JMP is the Marshall midi pre-amp range - JMP1 still being the current
>version.
>
Wrong. They made JMP 50 amps in the 70s. They were essentially 50
watt versions of the Super Leads I believe
>overdrive, to this end it uses a diode clamp at the front end.
>
>> The 800 series were better, but
>> still thin and buzzy. If you changed a few things they were ok.
>
>JCM800 comes in innumerable shapes and forms. Some have, like the JCM900,
>have diode clamps fitted, others do not. The topology of each, a key element
>in getting the characteristic sound from an amp, also varies widely
>throughout the range. JCM800s sound quite different across the range. Models
>1987 and 1959 have a traditional Super Lead/Bluesbreaker Topology, 2103, 2203,
Uuuh, I beg to differ. The early Super Leads used a single 250uf
across a 820 ohm resistor for the first gain stage. The first preamp
tube's cathode was jumpered and the bias network shared. Additionally, a
.68 bypass cap was placed across the 820 ohm cathode resistor in the 2nd
gain stage. THIS was the traditional Bluesbreaker/Plexi Topology you refer
to. The 1987 and 1959 JCM 800 circuit were similar but split the
first tube's cathode into individual bias networks with a 320uf/820ohm
combination in the dark channel, and a .68uf/2.7kohm combination in
the other channel. This completely changed the character of the amp. The
bass channel was dark and muddy, and the lead channel was thin, bright,
and buzzy. Using this configuration, you CANNOT nail the Hendrix or
Clapton tones of the mid/late 60s.
>
>>But the 900
>> is Marshall's cream piece right now.
>
>No its not. The 900 is a niche market aimed at heavy metal players. Main amp is
>still the 6100 series Anniversary, or rather its updated version, and the JTM
>Blues amps. It's biggest seller is the Valvestate8080 combo, but not relevant
>here as it is a hybrid.
>
Yes it is. Although the Valvestate may be a great seller, the JCM-900 IS the
Flagship product in the line.
>Is this supposed to mean anything? I had an old 1959 Super Lead Mk1 which
>was hand wired. It was the worst sounding, most unreliable amp I ever played
>"Hand wiring' is just marketing hype.
>
You're wrong again. I don't know what's wrong with your Super Lead but I've
rarely heard a hand wired Super Lead which cannot be made to sound absolutely
fantastic. The circuit board amps use extremely cheap surface mount caps, 1/4
watt resistors, and anything else that can save money. If you need to service
one, you have to take the whole circuit board out of the amp because the
components face downward on them ! Additionally, since Marshall and Fender
mount the Pots, Jacks, and switches to the board, you have to take them out too!
Ever try to work on an amp like that ! They are easy to make, period !
>>Which one is built with military grade parts?
>
>This is *Soviet* standard mil grade? I recall purchasing Soviet mil. grade
>metal film resistors some years back. They were worse than the commercial
>carbon versions available at my local electronics store and I had to spend a
>considerable amount of time going through them selecting. One third of them
>failed to even meet the stated tolerance standard.
Well, compare them to the teeny little surface mount caps that Marshall is
putting into their new amps such as the JCM-900 and the JTM-45 reissue. Also
look at the size of the output transformer and core material of the JCM-900.
It looks a little like a Fender Deluxe Transformer. Compare to the original
Marshalls or the Sovtek. No wonder, the JCM-900 is not that loud.
>
>> Which one is loaded with extra crap waiting to fail?
>
>What's this supposed to mean? I thought this was the technical section?
>
Again, I have to disagree with you. The JCM-900 has proven to be one of the
most unreliable amps in recent history. They have an extremely high failure
rate.
>It may well be that SOVTEKs do offer a way into cheap amps for the hard up
>player, and they, SOVTEK, should be applauded for that, but I think we can
>do without the sales hyperbole comparing it with a modern Marshall!
Why is it OK for Marshall to use sales talk and not Sovtek ?
>
>> guest . . . walk into Manny's and take "one of everything please!" I own a
>> Marshall, I love it. It's an early JTM-45. At $3000, it had better do
>> something that my $450 Midget doesn't.
>
>Well, that's an antique your comparing with now. Times have moved on somewhat.
>If it's blues your after, a JTM 30 combo series covers that base, is channel
>switching and costs about a third more than a SOVETEK Mig60 head only here
>(300 pounds vs 400 pounds) Once you add in a decent cabinet with Celestions
>for the SovTek, your right up there in the same price bracket as the Marshall.
Puleeeeeeeeze. The JTM 30 is the tackiest sounding amp I've heard in a while.
What a disappointment. It has NO traditional blues tone. It's a totally
unappealing, unoriginal sounding amp. At least the JCM-900 had some really
cool metal sounds. BTW, I think the lo gain channel in the JCM-900 dual reverb
sounds pretty good.
-Jaz
--
| Jack A Zucker Jack....@software.rockwell.com |
| Rockwell Software Inc. |
| 747 Alpha Drive Voice: 216-646-4668 |
| Highland Hts., OH 44143 Fax: 216-646-4484 |
David Roach
: gain stage. THIS was the traditional Bluesbreaker/Plexi Topology you refer
: first tube's cathode into individual bias networks with a 320uf/820ohm
: combination in the dark channel, and a .68uf/2.7kohm combination in
: the other channel. This completely changed the character of the amp. The
: bass channel was dark and muddy, and the lead channel was thin, bright,
: and buzzy. Using this configuration, you CANNOT nail the Hendrix or
: Clapton tones of the mid/late 60s.
: >>But the 900
: >> is Marshall's cream piece right now.
: >
: >No its not. The 900 is a niche market aimed at heavy metal players. Main amp is
: >still the 6100 series Anniversary, or rather its updated version, and the JTM
: >Blues amps. It's biggest seller is the Valvestate8080 combo, but not relevant
: >here as it is a hybrid.
: Yes it is. Although the Valvestate may be a great seller, the JCM-900 IS the
: Flagship product in the line.
According to my '95 Marshall catalog, the 6100 series anniversary amps
are the top-of-the-line, followed by the 900 series which occupy the
second section of the catalog.
: >Is this supposed to mean anything? I had an old 1959 Super Lead Mk1 which
: >was hand wired. It was the worst sounding, most unreliable amp I ever played
: >"Hand wiring' is just marketing hype.
: >
: Well, compare them to the teeny little surface mount caps that Marshall is
: putting into their new amps such as the JCM-900 and the JTM-45 reissue. Also
: look at the size of the output transformer and core material of the JCM-900.
: It looks a little like a Fender Deluxe Transformer. Compare to the original
: Marshalls or the Sovtek. No wonder, the JCM-900 is not that loud.
Like it or not, surface-mount is the future of most PC manufacturing.
The small size of a surface-mount cap does not make it "cheap", in
fact, these low mass components have withstood much higher levels of shock
and vibration in our environmental tests at H-P than ordinary through-hole
equivalents. Unfortunately, surface-mount requires special equipment
to replace components properly, and how many in the amp business are
going to run out and buy a $900 MetCal soldering station?
The extra "size" you see in a through-hole capacitor is just packaging;
de-encapsulate the part and what you get is essentially the surface-
mount part.
: >> Which one is loaded with extra crap waiting to fail?
: Again, I have to disagree with you. The JCM-900 has proven to be one of the
: most unreliable amps in recent history. They have an extremely high failure
: rate.
Higher than SOVTEK???
Don't want to start a war here, but *none* of the latest popular tube
amps have been all that reliable, partly due to the tubes themselves.
It would be interesting to see accurate stats on non-tube related
failure rates for the major brands. Let's face it-- these portable
amps need to be built like a brick sh**house to be able to withstand
the abuse they get from guitarists who play out, which makes me skeptical
that it can be done cheaply, as with some of these new tube amps.
Dave R.
bi...@boi.hp.com
along. After working on a few of them I have come to the conclusion that
the designs don't need "the bugs out", they need good tubes! We have been
having problems with the heads that are tube related. A few of the the tubes
we've sold off the shelf are also defective, EL34's and 6L6's. I've been
seeing high resistance paths between pins of the tubes. It isn't a total
short, but the resistance is low enough to pull up the bias voltages and
get things heated. I really hate that when it happens to a client's vintage
Marshall and melts his tube sockets!!!!
Anyone else have good/bad experiences with Sovtek?
P.S. I really do like these amps and the price is unbeatable!
bigd
TimTube
Well said, kudos to jaz.
Tim
David A. Morning
> Jack A. Zucker (jack....@software.rockwell.com) wrote:
Jaz? Did you write this? (I haven't got the complete article, so I don't
know? If you did mail me, its wrong, or I'm mis-reading an incomplete article.
> : gain stage. THIS was the traditional Bluesbreaker/Plexi Topology you refer
> : to.
No. 1959 and 1959 Mk2 Plexis, dating from 1970 BOTH use seperate bias with the
component values you mention below for the JCM800. The *only* difference is
that the bypass cap is 250uF in the original and 320uF in the JCM800. This is
an irrelevant change, this capacitor determines the low froquency cut off
point of the stage, acting like a shelving filter. The turnover frequency
is determined by the impedance of the RC combination. Electrolytic caps
have a tolerance rating of +100%/-50%, in otherwords, its true value could
lie anywhere between half and double the nominal value. Quick scribble on
'cigarette pack' showes that changing from a 250u to a 320 will lower the
turnover point by about 5 Hz however, once you factor in cap tolerance, this
difference is swamped by tolerance variation between models of the same era
and, thus, is by and large irrelevant. In other words, its not even worth
arguing over, other factors such as component tolerance will have a *much*
larger effect down at such small levels of change.
I presume the point of the Bluesbreaker your making is that it was a Bassman
clone? This is true, but 'topology' is not about component values or bias
points, it is the general layout of the amp, and Marshall have, by and large
stuck to the format,
gain stage-->pot/voicing--->gain stage--->cathode follower--->tone stack.
..and this is essentially the old Bassman topology. Whether or not the cathode
bias resistor is shared is by and large irrelevant, since the working points
are still the same, being voltage, not current defined, and only one channel
tends to get used at one time.
> : The 1987 and 1959 JCM 800 circuit were similar but split the
> : first tube's cathode into individual bias networks with a 320uf/820ohm
> : combination in the dark channel, and a .68uf/2.7kohm combination in
> : the other channel. This completely changed the character of the amp. The
> : bass channel was dark and muddy, and the lead channel was thin, bright,
> : and buzzy. Using this configuration, you CANNOT nail the Hendrix or
> : Clapton tones of the mid/late 60s.
I didn't say you could, A whole range of other factors come into 'nailing '
a tone, including power amp, rectifier, output transformers, power stage
working points, etc etc... The point I was trying to make, without bogging
it down in unneccessary technical details, was that you could not dismiss
an entire range of amps with such a wide diversity of topologies as being
all characterised as 'thin and buzzy'. Bluesbreaker and Super Lead were merely
convenient terms that non-technical people reading this may be able to relate
to.
>
> : Yes it is. Although the Valvestate may be a great seller, the JCM-900 IS the
> : Flagship product in the line.
No, and indeed the future of the JCM900 range is unclear. In a recent interview,
in Guitarist magazine (maybe 6 months ago), Jim Marshall stated quite
categorically that the Anniversary was very much the flag-ship amp. He went
on at great length about the Mk2 version soon to be (now?) released and how a
great deal of R & D has gone into it from lessons learned from the Mk1. When
asked about the JCM900, he was somewhat vague making references to the 900S
not being as successful as they hoped. Currently Marshall are promoting the
JTM range heavily, with some larger versions ion the pipeline. The 900 may be
doomed.
> : >Is this supposed to mean anything? I had an old 1959 Super Lead Mk1 which
> : >was hand wired. It was the worst sounding, most unreliable amp I ever
played
> : >"Hand wiring' is just marketing hype.
> : >
>
> : Well, compare them to the teeny little surface mount caps that Marshall is
> : putting into their new amps such as the JCM-900 and the JTM-45 reissue.
That's not relevant. I'm currently using a machine packed with surface mount
components, running in a hostile environment (my office!) to type this
message. It has run flawlessly for at least 5 years now. Surface mount
compnents are now used regularly in 'mission critical' and 'hostile' areas
and proved there worth. What's wrong with using them in amps if they are
engineered in properly?
Size isn't everything ya know jaz! :-)
>
> : >> Which one is loaded with extra crap waiting to fail?
>
> : Again, I have to disagree with you. The JCM-900 has proven to be one of the
> : most unreliable amps in recent history. They have an extremely high failure
> : rate.
Perhaps, I don't have any figures at hand to show either way, but how does
it compare with the SOVTEK?
My apologies to Jaz if this article has been wrongly attributed, I'd be
grateful if someone could forward me the original, which didn't make it here.
Dr Distortion
: JCM900 series is aimed primarily at the heavy metal market, lots of heavy
: overdrive, to this end it uses a diode clamp at the front end.
I'm sorry to nitpick, but...
That zener clamp on the input isn't doing any clipping. They're 9.1V zeners,
and there's no way that the signal coming out of a guitar--which is down
in the millivolt range--is going to make them fire. Even regular silicon
or even germanium diodes have too high a forward voltage drop to be able
to clip an unamplified guitar signal.
Why are they there? Input protection is my guess, although it doesn't seem
necessary. One other possibility--however remote--is that they were put
there to protect the guitar pickup in the very unlikely event that the
tube shorts AND the input coupling cap pinholes. But I doubt that's what
they had in mind.
But make no mistake--the clipping mechanism :is: solid-state. It's a diode
bridge, but it comes later on in the preamp circuit. The JCM900 is a poor
excuse for a tube amp, that's for sure. They should have just made it as
an all-transistor amp, rather than trying to deceive the public.
: "Hand wiring' is just marketing hype.
Sometimes it is, but not always. It makes an amp a hell of a lot easier to
work on, and oftentimes more reliable as well. It's :possible: that
there's a tonal difference, but I don't care to speculate about that.
Personally, I don't think the distributed capacitance on a PCB is going to
make much difference in a high-impedance tube circuit, but I could be
wrong. At any rate, handwiring does have concrete advantages. Everything
I build is handwired, and I intend to keep it that way.
By the way, the Sovtek heads I've seen use circuit boards. They're not
true handwired amps, although the fact that the pots and tube sockets are
chassis-mounted does give them an advantage over, say, Peavey.
(Then again, just about any amp is better than a Peavey, isn't it?).
The Sovteks do sound good, though, and are a good value for the money.
People know this, and it's really not necessary for Mr. Portnoy to slam
the competition in order to sell amps. They sell themselves...
: Just because it says 'mil grade' doesn't mean its top quality. I'd put a
: Mullard 'nos' EL34 up against any of these Sovtek mil grade EL34s anyday -
: if I could afford the Mullard!
I have to agree with you, based on my very limited experience with the
Sovtek EL34. The ones I've gotten have been total shit: poorly matched,
poorly made. A couple shorted out on me; another lost its vacuum. I think
the Czech Tesla EL34s are much better, at least the ones I've tried.
Luckily, most other Sovtek tubes--e.g., their 5881, 12AX7 and 5AR4 types--
are really good and haven't given me trouble. I do avoid their 6V6,
though, because I've heard too many horror stories about them from fellow
techs, guys whom I've known for years and whom I trust.
: groups, the reliability of the original Mig 50s, 60s and 100s isn't all that
: great
A guy I know had his MIG-30 (the predecessor to the MIG-50) catch fire
during a rehearsal; he was so pissed off about it, he just kept playing
and let the thing burn up. Still, that doesn't necessarily mean that
Sovteks on the whole are poorly made; I've seen old Fenders blow up, too,
and we all know that Fender made one hell of an amp in its day.
Jack A. Zucker
>
>Jack A. Zucker (jack....@software.rockwell.com) wrote:
>
>: Well, compare them to the teeny little surface mount caps that
Marshall is
>: putting into their new amps such as the JCM-900 and the JTM-45
>: look at the size of the output transformer and core material of the
JCM-900.
>: It looks a little like a Fender Deluxe Transformer. Compare to the
original
>: Marshalls or the Sovtek. No wonder, the JCM-900 is not that loud.
>
> Like it or not, surface-mount is the future of most PC
manufacturing.
> The small size of a surface-mount cap does not make it "cheap", in
> fact, these low mass components have withstood much higher levels
of shock
> and vibration in our environmental tests at H-P than ordinary
through-hole
> equivalents. Unfortunately, surface-mount requires special
equipment
> to replace components properly, and how many in the amp business
are
> going to run out and buy a $900 MetCal soldering station?
> The extra "size" you see in a through-hole capacitor is just
packaging;
> de-encapsulate the part and what you get is essentially the
surface-
> mount part.
>
Of course it's the future of modern manufacturing. It's cheap ! The
manufacturers are trying to maximize their profits. If it's at the
expense of a little thing like sound quality or reliability, they don't
care too much. As long as people keep buying them, they'll keep selling
them. It's like GM in the 70s and 80s. All the reissues (particularly
Fender) sound like crap. Have you ever tried to work on one of those
amps? You have to not only remove the entire circuit board, but you have
to disconnect the pots and jacks from the chassis since they are soldered
directly to the pc board. Its not fun. Fender also decided to use 1/4
watt resistors in the reissues. If you do something silly like replace
the cheap Chinese 6L6 tubes in the Bassman with real 5881 tubes which
draw more current, the screen grid resistors overheat and melt the
soldering connections. I've seen this happen on 3 or 4 bassmans.
>: >> Which one is loaded with extra crap waiting to fail?
>
>: Again, I have to disagree with you. The JCM-900 has proven to be one
of the
>: most unreliable amps in recent history. They have an extremely high
failure
>: rate.
>
> Higher than SOVTEK???
> Don't want to start a war here, but *none* of the latest popular
tube
I don't know particularly about Sovtek's reliability. I do agree with you
regarding the latest tube amps. Here's the deal: Fender and Marshall amps
from the 60's are 25-30 years old. Most are still going strong. Do you
really think JCM-900s will still be around in 2020 ?
Jack A. Zucker
says...
>
>
>No. 1959 and 1959 Mk2 Plexis, dating from 1970 BOTH use seperate bias with
the
>component values you mention below for the JCM800. The *only* difference is
The 1970 amps you mention are bright and shrill. Obviously the layout is
similar but they do not sound the same as the classic amps of 1967-1968. The
originals used the single 250uf/820 cathode bias tied together.
>
>
>I didn't say you could, A whole range of other factors come into 'nailing '
>a tone, including power amp, rectifier, output transformers, power stage
>working points, etc etc... The point I was trying to make, without bogging
>it down in unneccessary technical details, was that you could not dismiss
>an entire range of amps with such a wide diversity of topologies as being
>all characterised as 'thin and buzzy'. Bluesbreaker and Super Lead were
merely
>convenient terms that non-technical people reading this may be able to relate
>to.
Let's simplify even further. IMHO, the classic Marshall sounds are the
Bluesbreaker era Clapton stuff, the Hendrix Marshall stuff, and the Cream
stuff. The modern '70s Super Lead and the Later JCM-800 stuff just does not
get those classic tones.
>
>That's not relevant. I'm currently using a machine packed with surface mount
>components, running in a hostile environment (my office!) to type this
>message. It has run flawlessly for at least 5 years now. Surface mount
>compnents are now used regularly in 'mission critical' and 'hostile' areas
>and proved there worth. What's wrong with using them in amps if they are
>engineered in properly?
Well for one thing, you do not have beer gulping roadies tossing your computer
into the back of a van ! :-) I agree with you regarding the mission
critical/hostile stuff. Obviously, the military is not using hand wired tube
based analog equipment. On the other hand, the new military gear does not
sound as good as the older vintage stuff. :-)
-Jaz
TimTube
craftsmanship out the window. You can, however, for a dollar figure
usually double that of production stuff, get into hand crafted stuff that
is probably equal in construction quality to the old stuff (with the
benefit of the technical advances).
For instance, it used to be 20 or 40 years ago if you bought a Fender
guitar or amp it was a quality piece of equipment. You can still get that
quality but it comes out of the Custom Shop. The standard production stuff
is very compromised. The Custom Shop pieces are great, the ToneMaster amp
is a monster. The heads are about $1600, Custom Shop Strats begin around
$1050. If you look at the inflation rate these are not out of line prices.
Same with Matchless, PRS, Naylor, Victoria, ToneCity, Hoffman, Kendrick,
and lots of others folks out there making beautifully crafted tone tools.
Tim
David A. Morning
jack....@software.rockwell.com (Jack A. Zucker) wrote:
> In article <dam-040895...@kerrera.dcs.gla.ac.uk>, d...@dcs.gla.ac.uk
> says...
> >
> >
> >No. 1959 and 1959 Mk2 Plexis, dating from 1970 BOTH use seperate bias with
> the
> >component values you mention below for the JCM800. The *only* difference is
>
> The 1970 amps you mention are bright and shrill.
Well of course they are, on the bright channel, since it has a great deal
of tone shaping, but the normal channel on the 70's 1959 model is essentially
that of a Bassman which, in turn, was the pre-amp of the original JTM-45
Bluesbreaker.
> Obviously the layout is
> similar but they do not sound the same as the classic amps of 1967-1968.
Are we talking JTM-45 or SuperLead here? Super Lead came out in 1966.
> The
> originals used the single 250uf/820 cathode bias tied together.
SuperLeads didn't, They were redesigned from scratch to add an extra
channel with more dramatic (ie bright) voicing. The method of cathode bias is
by and large irrelevant. Whether both channels used a common 820/250u bias
network, or each channel used a seperate 820/250u (or indeed 330u), there
would be little discernable difference between the sounds of each channels
1st stage. What the SuperLead did was to do precisely this but, rather than
leave both channels identical, it altered one of the channels by increasing
the cathode bias resistor to 2k7, which altered the working point and gain,
while decreasing the value of the bypass cap to 0.68u, which meant it didn't
kick in until much higher in the frequency band, a simple treble boost in
otherwords. An addition two further stages of treble boost were added to this
channel, as well as reducing the value of the first stage coupling cap to add
an additional bass cut. The result was one channel extremely bright and toppy
while the other was flat but still a clone of the Bassman's 1st stage. The
JCM800 model 1987 followed exactly the same path, the JCM800 2100 and 2200
range dropped the 'flat' channel in favour of something more like the 'bright'
channel, but with altered bias points and an extra gain stage. Meanwhile,
back at the Super Lead, it underwent significant post-tone control and
power supply changes as it mutated from the JTM-45.
> >
> >I didn't say you could, A whole range of other factors come into 'nailing '
> >a tone, including power amp, rectifier, output transformers, power stage
> >working points, etc etc... The point I was trying to make, without bogging
> >it down in unneccessary technical details, was that you could not dismiss
> >an entire range of amps with such a wide diversity of topologies as being
> >all characterised as 'thin and buzzy'. Bluesbreaker and Super Lead were
> merely
> >convenient terms that non-technical people reading this may be able to relate
> >to.
>
> Let's simplify even further. IMHO, the classic Marshall sounds are the
> Bluesbreaker era Clapton stuff, the Hendrix Marshall stuff, and the Cream
> stuff. The modern '70s Super Lead and the Later JCM-800 stuff just does not
> get those classic tones.
Once again, I didn't say they did. You appear to define anything prior to 1970
as 'classic', with the connotation that this was the absolute epitome of sound.
That is your personal choice and taste and, thus, remains a matter of opinion.
It is not, per se, relevant to the issue which was a claim that all JCM800s
are 'thin and buzzy'.
> >That's not relevant. I'm currently using a machine packed with surface mount
> >components, running in a hostile environment (my office!) to type this
> >message. It has run flawlessly for at least 5 years now. Surface mount
> >compnents are now used regularly in 'mission critical' and 'hostile' areas
> >and proved there worth. What's wrong with using them in amps if they are
> >engineered in properly?
>
> Well for one thing, you do not have beer gulping roadies tossing your
computer
> into the back of a van !
No, but I have beer gulping technicians flinging into the back of a University
van for various demos from time to time!
>I agree with you regarding the mission
> critical/hostile stuff. Obviously, the military is not using hand wired tube
> based analog equipment.
No, they abandoned it as unreliable. The one big advantage of SMDs (surface
mount devices) is that they have far less mass to flap around and break loose
in situations where they are thrown around. Indeed, SMD board can and are
used in rotating parts of alternators. If they are properly engineered into a
design, there is no good reason not to use them. The issue of PCBs in tube
amps has been well understood for many years. I have a 50 watt valve PA amp
dating from the 1950s, it uses PCBs (and indeed mounts the pre-amp tubes
on them), and still works fine. Hiwatt found out the hard way how NOT to
use PCBs in an amp. If its done properly with due care and attention to
loadings and heat circulation, they can be very reliable. If they are done
badly, they can be awful both soundwise and reliability wise.