Slightly odd output stage configuration. Thoughts ?
Arfa Daily
Classic 30. All pretty straightforward cap changes and so on. However, he
also asked me to look into fitting a pentode / triode switch whilst I was at
it. At first glance, this didn't look like a problem. The output stage is a
fairly classic AB class using 4 x EL84 tubes as two paralleled pairs. Anodes
of each pair commoned. Cathodes all commoned and decked. Grids of each pair
commoned via individual 47k stoppers. But then, things get a little odd
around the screen grids. One tube of each pair, has its screen grid fed by a
100 ohm 5 watt resistor off the "screen" supply rail, whilst the other of
each pair, has its screen grid fed *direct* from the "screen" supply rail.
I don't think I've seen this done before. I've seen one screen resistor
feeding both tubes of a pair, or one resistor per screen, but not just one
tube having a screen feed resistor. Apart from anything else, I wouldn't
normally have considered it very good design practice to have no current
limiting at all in place. Also, it will mean that the screen voltage will be
higher on one tube of the pair, than the other. I doubt that it would have a
significant effect on the operation of the stage, but just interested as to
whether anyone else has come across this configuration, and knows the design
reasoning behind it. Anyone got any opinions about just strapping the
screens to the anodes on each pair via a switch, to implement a triode mode
?
Arfa
Meat Plow
Several amp and tone stack mods. Variable cathode bias, OD mod on CH2, OT
replacement, speaker replacement.
blueguitar.org/new/articles/blue_gtr/amps/peavey/c30_origmod.pdf
--
Live Fast, Die Young and Leave a Pretty Corpse
Phil Allison
"Arfa Daily"
>
>A muso customer has asked me to carry out some tonal mods to his Peavey
>Classic 30. All pretty straightforward cap changes and so on. However, he
>also asked me to look into fitting a pentode / triode switch whilst I was
>at it. At first glance, this didn't look like a problem. The output stage
>is a fairly classic AB class using 4 x EL84 tubes as two paralleled pairs.
>Anodes of each pair commoned. Cathodes all commoned and decked. Grids of
>each pair commoned via individual 47k stoppers. But then, things get a
>little odd around the screen grids. One tube of each pair, has its screen
>grid fed by a 100 ohm 5 watt resistor off the "screen" supply rail, whilst
>the other of each pair, has its screen grid fed *direct* from the "screen"
>supply rail.
>
> I don't think I've seen this done before.
** Peavey have been doing that since their first 4 tube ( 6L6GC) models.
See Peavey Deuce from 1975:
http://www.el34world.com/charts/Schematics/files/peavey/peavy_deuce-b.pdf
Strangely, the 6 tube models have 6 screen resistors.
http://www.el34world.com/charts/Schematics/files/peavey/Peavey_Mace_Deuce.pdf
> I doubt that it would have a significant effect on the operation of the
> stage, but just interested as to whether anyone else has come across this
> configuration, and knows the design reasoning behind it.
** Same question has puzzled me for ages - I suspect it could be an error
that has just got repeated over the decades. No-one but Peavey knows for
sure.
>Anyone got any opinions about just strapping the screens to the anodes on
>each pair via a switch, to implement a triode mode ?
** It better be a damn good switch, insulation and voltage rating wise -
most makers who have such triode/pentode switching use a very hefty slide
switch.
Also, the power output will of course drop in triode mode and each EL84 will
dissipate more heat under overdrive. Combined with their use of a
"concertina" phase splitter, I suspect that overdrive clipping will not be
symmetrical.
Not recommended.
.... Phil
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8squrg...@mid.individual.net...
>
> "Arfa Daily"
>>
>>A muso customer has asked me to carry out some tonal mods to his Peavey
>>Classic 30. All pretty straightforward cap changes and so on. However, he
>>also asked me to look into fitting a pentode / triode switch whilst I was
>>at it. At first glance, this didn't look like a problem. The output stage
>>is a fairly classic AB class using 4 x EL84 tubes as two paralleled pairs.
>>Anodes of each pair commoned. Cathodes all commoned and decked. Grids of
>>each pair commoned via individual 47k stoppers. But then, things get a
>>little odd around the screen grids. One tube of each pair, has its screen
>>grid fed by a 100 ohm 5 watt resistor off the "screen" supply rail, whilst
>>the other of each pair, has its screen grid fed *direct* from the "screen"
>>supply rail.
>>
>> I don't think I've seen this done before.
>
> ** Peavey have been doing that since their first 4 tube ( 6L6GC) models.
>
> See Peavey Deuce from 1975:
>
> http://www.el34world.com/charts/Schematics/files/peavey/peavy_deuce-b.pdf
>
> Strangely, the 6 tube models have 6 screen resistors.
>
> http://www.el34world.com/charts/Schematics/files/peavey/Peavey_Mace_Deuce.pdf
>
>
>> I doubt that it would have a significant effect on the operation of the
>> stage, but just interested as to whether anyone else has come across this
>> configuration, and knows the design reasoning behind it.
>
> ** Same question has puzzled me for ages - I suspect it could be an error
> that has just got repeated over the decades. No-one but Peavey knows for
> sure.
Yes Phil. I too wondered whether it was an error. At first glance, I thought
that the two screen grids were commoned, and then taken back to a single
resistor, but when I looked at the print layout diagram a bit more
carefully, I could see that what appeared to be the case was that one screen
went to the 'cold' side of the resistor, and the other went to the 'hot'
side. A squint at the schematic then confirmed this ...
>
>>Anyone got any opinions about just strapping the screens to the anodes on
>>each pair via a switch, to implement a triode mode ?
>
> ** It better be a damn good switch, insulation and voltage rating wise -
> most makers who have such triode/pentode switching use a very hefty slide
> switch.
Yes indeed, my thoughts as well. Anode supply is quoted at 330v nominal, so
a switch rated to 250v ac, as most are, should be good for that. At the end
of the day, many tube amps use the same switch for the HT standby switching,
as they do for the mains, and lots of them run with an HT of much more than
330v.
>
> Also, the power output will of course drop in triode mode and each EL84
> will dissipate more heat under overdrive. Combined with their use of a
> "concertina" phase splitter, I suspect that overdrive clipping will not be
> symmetrical.
I hadn't considered that there might be any changes to the phase splitter
output as a result of such a change. What leads you to think that this might
be the case ?
>
> Not recommended.
Well, not something that I would normally recommend either, and the owner is
happy to live without the mod. He just thought that he would like to give it
a try if it was practical, whilst I was in there doing the other work.
Apparently, he would like to use it in 'triode' mode when he is at home
practicing. It's not actually a hard mod to carry out, and would be
reasonably easy to implement with the current print layout. I think what I
will probably do is to just 'hang' the mod in temporarily to see how it
performs, before doing any chassis drilling for switch fitting. If it seems
to work ok, then I'll finish it off. If not, I'll just recommend against it.
>
>
> .... Phil
Thanks for your comments Phil. Useful
Arfa
Arfa Daily
"Meat Plow" <mhy...@yahoo.com> wrote in message
news:pan.2011.02...@lmao.lol.lol...
Hi Meat. Yes, it is Blue Guitar mods that he wants to do. He is not
interested in the changes to the tone stack. He wants the output bias
changing from fixed grid to cathode auto, he wants the C4 cap value change
in the overdrive channel, and he wants the input simplification mod, where
all the C-R garbage between the I/P socket and the first 12AX7 grid is
removed, and a simple series resistor and grid return resistor are put in
their place, a la typical Fender and Marshall I/P schemes.
Arfa
Phil Allison
"Arfa Daily"
> "Phil Allison"
>>>Anyone got any opinions about just strapping the screens to the anodes on
>>>each pair via a switch, to implement a triode mode ?
>>
>> ** It better be a damn good switch, insulation and voltage rating wise -
>> most makers who have such triode/pentode switching use a very hefty slide
>> switch.
>
> Yes indeed, my thoughts as well. Anode supply is quoted at 330v nominal,
> so a switch rated to 250v ac, as most are, should be good for that.
** Nope.
Switches ( and relays) rated for AC operation are not suitable for DC
voltages above about 24 to 30 volts at the same current. DC arcs are tough
SOBs to break.
> At the end of the day, many tube amps use the same switch for the HT
> standby switching,
** All *sensible* designs switch the AC secondary of the transformer.
Those that switch the DC rail directly often arc and burn - even though
the current is generally only 100mA or so.
Fender ( for example ) did this in many older models, but chose a particular
switch that had a very large opening clearance to survive the inevitable
arcing - ESPECIALLY if the standby switch was ever operated under full
power.
Some Boogie models made the massive blunder of having the standby switch
parallel two electros ( one charged, one not) when it was closed. Splat.
>> Also, the power output will of course drop in triode mode and each EL84
>> will dissipate more heat under overdrive. Combined with their use of a
>> "concertina" phase splitter, I suspect that overdrive clipping will not
>> be symmetrical.
>
>
> I hadn't considered that there might be any changes to the phase splitter
> output as a result of such a change.
** Please try reading what is there.
The PS dos not itself change ( ??) but the job it has to do does - cos
the required grid drive to the EL84s is much higher in triode mode.
Concertina ( single triode ) PS circuits have less output and clip
asymmetrically compared to twin triode PS circuits.
>> Not recommended.
>
> Well, not something that I would normally recommend either, and the owner
> is happy to live without the mod. He just thought that he would like to
> give it a try if it was practical, whilst I was in there doing the other
> work. Apparently, he would like to use it in 'triode' mode when he is at
> home practicing.
** Wot a fuckwit.
It only drops the power by half or 3 dB.
.... Phil
Phil Allison
"Arfa Daily"
>> ** Same question has puzzled me for ages - I suspect it could be an error
>> that has just got repeated over the decades. No-one but Peavey knows for
>> sure.
>
** Here is my analysis:
The low value of 100 ohms in series with G2 has no significant effect on the
operation of a 6L6GC.
Peavey designs have a large value resistor ( 300 or 400 ohms 10W ) in the
feed to all G2s - unlike other amps that generally have a filter choke with
low DC resistance.
So, the 100 ohm resistors are there for factory test purposes only - so
staff can check if valves are drawing G2 currents within pre-determined
limits. G2 current levels mimic cathode currents for a given valve type and
brand.
By measuring the voltage drop across the 300 or 400 ohm resistor AND each
100 ohm in the G2 feeds - correct operation can be established.
Dunno about others - but I routinely check the voltage drop across each G2
resistor when servicing amps and replacing valves. It should be similar for
all valves in an output stage.
.... Phil
Phil Allison
"Arfa Daily"
> He wants the output bias changing from fixed grid to cathode auto,
** That will either lose you a lot of output power or cook that puny power
tranny ( by going close to class A operation) if you don't do it the smart
way.
Not recommended either.
..... Phil
David Nebenzahl
> Also, the power output will of course drop in triode mode and each EL84 will
> dissipate more heat under overdrive. Combined with their use of a
> "concertina" phase splitter, I suspect that overdrive clipping will not be
> symmetrical.
If you wouldn't mind indulging my relative ignorance for a minute, that
"concertina" stage business got my curiosity up. So I found the two
triode (12AX7) stages before the EL84s, and it looks to me like the
first stage (V3A) is a phase inverter, with the other triode acting as
*another* phase inverter cascaded from the first stage, presumably with
unity gain. Is that correct?
So it seems this setup would be quite problem-prone, with possible phase
distortion and phase imbalance (or crossover distortion) effects. So why
would anyone use such a phase inverter, when there are much better ones
available?
--
The phrase "jump the shark" itself jumped the shark about a decade ago.
- Usenet
Phil Allison
"David Nebenzahl"
Phil Allison spake thus:
>
>> Also, the power output will of course drop in triode mode and each EL84
>> will dissipate more heat under overdrive. Combined with their use of a
>> "concertina" phase splitter, I suspect that overdrive clipping will not
>> be symmetrical.
>
> If you wouldn't mind indulging my relative ignorance for a minute, that
> "concertina" stage business got my curiosity up. So I found the two triode
> (12AX7) stages before the EL84s, and it looks to me like the first stage
> (V3A) is a phase inverter,
** With an imagination like that - you should be writing fiction for a
living.
A " phase inverter" ( or phase splitter) has equal and opposite polarity
outputs.
> with the other triode acting as *another* phase inverter cascaded from the
> first stage, presumably with unity gain. Is that correct?
** Nope.
V3A is a voltage amplifier ( gain of about 50 before NFB) while V3B is the
"concertina" phase inverter. Concertina circuits always have equal plate and
cathode resistors and in operation, the voltage between the plate and
cathode grows and falls with audio drive like a concertina being pumped in
and out.
The cathode of V3A acts as a negative ( opposite phase) input for feedback
from the output transformer secondary.
Because of the easy drive requirements of an EL84, such a concertina circuit
is able to send them deep into overdrive - while maintaining good symmetry.
Not so for 6L6GC or EL34 stages which need several times more drive voltage.
.... Phil
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8srb56...@mid.individual.net...
Well, that one is a well known and documented mod for that amp, so I'm not
too concerned about doing it. However, I take (and somewhat agree with) your
point. Personally, I would prefer to make the fixed grid bias variable
within 'blues to rock' limits, and give him another knob to twiddle with,
but he is adamant that he wants that particular cathode bias mod. I did
offer to make that switchable for him, but he just wants it changing and
leaving at that. You can only advise these people, but in the end, it's his
amp, and if he's prepared to pay the money to have it done at his own risk,
then that's fine by me ...
Arfa
Phil Allison
"Arfa Daily = MORONIC TROLL "
>>
>>> He wants the output bias changing from fixed grid to cathode auto,
>
>>
>> ** That will either lose you a lot of output power or cook that puny
>> power tranny ( by going close to class A operation) if you don't do it
>> the smart way.
>>
>> Not recommended either.
>
>
> Well, that one is a well known and documented mod for that amp, so I'm not
> too concerned about doing it.
** ROTFLMAO !!
Wot a fucking moron the stupid pommy cunt is.
Only posts questions he already THINKS he knows the answers to.
Just so the pommy cunt can smugly contradict anyone who dares to reply.
Wot a fucking MORON !!!!!!!!!!!!
..... Phil
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8sroeo...@mid.individual.net...
So is it the fact that the circuit relies to some extent on NFB for correct
symmetrical overdrive operation, that leads you to believe that this might
be upset by operating in a pseudo-triode mode ?
Interesting analysis. I'll report back when I've tried it
Arfa
Phil Allison
"Arfa Daily is total FUCKWIT TROLL "
>
> So is it the fact that the circuit relies to some extent on NFB for
> correct symmetrical overdrive operation, that leads you to believe that
> this might be upset by operating in a pseudo-triode mode ?
** Giant HUH ??????????
How does anyone get THAT nonsense from anything I posted ???
Hey Daily - you are a fucking IDIOT !!
GO DROP DEAD
.... Phil
William Sommerwerck
> Wot a fucking moron the stupid pommy cunt is.
> Only posts questions he already THINKS he knows the answers to.
> Just so the pommy cunt can smugly contradict anyone who dares to reply.
> Wot a fucking MORON !!!!!!!!!!!!
<hands on hips; huffy>
You are SO out of line, mister!
</hands on hips; huffy>
I guess you have never been unsure about something, and asked for
confirmation. How nice it is to be omniscient!
Meat Plow
Looks like a good bit of work in store for you. The hard part is to end
up with tone that doesn't sound like ass.
Phil Allison
"William Sommerwanker "
>
>> ** ROTFLMAO !!
>> Wot a fucking moron the stupid pommy cunt is.
>> Only posts questions he already THINKS he knows the answers to.
>> Just so the pommy cunt can smugly contradict anyone who dares to reply.
>> Wot a fucking MORON !!!!!!!!!!!!
>
>
> confirmation.
** That is NOT what the CUNT did !!
You illiterate, fuckwit bloody TROLL.
Meat Plow
> illiterate, fuckwit bloody TROLL.
Yes you are. You can't wait for someone to reply to
your trolls so you can attack them. I take that back,
your not a Troll. Trolls have some scruples. You wouldn't
recognize scruples if they booted your weasel nuts up your
fucking greasy, shit encrusted throat.
Phil Allison
"Meat Plow is a Lying Retarded PIG "
> Could refit with two EL34s.
** Make any issues worse, not better.
> My Musicman 112 combo uses a pair of Mullards
> at around 700v plate.
** And only half that voltage on the screens.
Not relevant at all - fuckhead.
Now how about you post something that MAKES SENSE.
But you cannot.
And you keep proving it.
My god you are retarded, fucking jerk.
.... Phil
Charles
humbly suggest that he be ignored.
David Nebenzahl
> "David Nebenzahl"
>
> Phil Allison spake thus:
>>
>>> Also, the power output will of course drop in triode mode and
>>> each EL84 will dissipate more heat under overdrive. Combined with
>>> their use of a "concertina" phase splitter, I suspect that
>>> overdrive clipping will not be symmetrical.
>>
>> If you wouldn't mind indulging my relative ignorance for a minute,
>> that "concertina" stage business got my curiosity up. So I found
>> the two triode (12AX7) stages before the EL84s, and it looks to me
>> like the first stage (V3A) is a phase inverter,
>
> ** With an imagination like that - you should be writing fiction for a
> living.
>
> A " phase inverter" ( or phase splitter) has equal and opposite polarity
> outputs.
OK, my bad: poor choice of terminology. What I meant to say is that both
stages are inverting stages, being common cathode. Correct? Since one
pair of EL84s seems to be driven from V3As plate and the other from V3Bs
plate, isn't this basically how this phase splitter works? One pair of
output tubes gets an inverted signal, the other pair gets an
inverted-inverted one.
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8st8gu...@mid.individual.net...
Oh boy. The Antipodean twat is off and running again ... What is it with
you Philip ? I know we all take the piss out of you about forgetting to take
your meds, but is that really the case ? Or do you smoke funny stuff that
addles your dumbarsed brain or something ? Or maybe you've got a drink habit
? Whatever it is pal, you seriously, and I mean SERIOUSLY need to address it
before you one day do something that you are really gonna regret when you
sober up / come down / remember to take your meds again. The really sad
thing is that when you are in control, you are actually lucid and make real
sense. I was actually treating you as an adult in this thread, and being ok
with you, but stupid me for being fooled by you again. How many times is it
that you've gone off on one to me now ? Five ? Six maybe, over the years ?
And still you haven't learnt, have you ? I simply don't fucking CARE, you
dopey twat. You can call me what you like, it will still be you that's the
stupid one on here, that everybody is laughing at. Read that carefully.
Laughing AT, not WITH.
Now be a good boy and do whatever you need to get your sensible head back
on. And if you can do that, and come back into the conversation making some
sense, then that's fine, and we'll all have a little chuckle, and put it
down to good ol' Philip, just having one of his little episodes. And if you
can't, then just turn off your computer, and crawl back into your darkened
room or back under your rock or wherever it is you sleep, and don't come
back out until you've learnt how to behave again. Capiche ?
Arfa
Phil Allison
"Charles the Puke "
> Until P.A. develops a reasonable command of English
** Whaaattttt ??
My command of the English language is second to none
- you vile, autistic shithead.
Phil Allison
"Arfa Daily = 100% MORONIC TROLL "
> Well, that one is a well known and documented mod for that amp, so I'm not
> too concerned about doing it.
** ROTFLMAO !!
Wot a fucking pommy moron !!!
Only posts questions it already THINKS it knows the answers to - when it
has not got one clue.
Just so the pommy cunt can smugly contradict anyone who dares to reply.
Wot a fucking MORON !!!!!!!!!!!!
Kick the vile pommy ass totally off the NG.
..... Phil
Phil Allison
"David Nebenzahl"
Phil Allison spake thus:
>
>>> that "concertina" stage business got my curiosity up. So I found
>>> the two triode (12AX7) stages before the EL84s, and it looks to me
>>> like the first stage (V3A) is a phase inverter,
>>
>> ** With an imagination like that - you should be writing fiction for a
>> living.
>>
>> A " phase inverter" ( or phase splitter) has equal and opposite polarity
>> outputs.
>
> OK, my bad: poor choice of terminology. What I meant to say is that both
> stages are inverting stages, being common cathode. Correct?
** I already explained the circuit - but you decide to snip the lot.
Here is the schem:
http://www.el34world.com/charts/Schematics/files/peavey/peavey_classic30.pdf
Here is the missing explanation:
" V3A is a voltage amplifier ( gain of about 50 before NFB) while V3B is
the
"concertina" phase inverter. Concertina circuits always have equal plate and
cathode resistors and in operation, the voltage between the plate and
cathode grows and falls with audio drive like a concertina being pumped in
and out.
The cathode of V3A acts as a negative ( opposite phase) input for feedback
from the output transformer secondary. "
> Since one pair of EL84s seems to be driven from V3As plate
** You looking at the schem above or not ?
V3A drives V3B which delivers TWO anti-phase signals (one from the plate and
one from the cathode) so the push-pull output stage can work.
V3B has a gain of 2 as the output is across the plate and cathode.
.... Phil
William Sommerwerck
Jekyll and Hyde -- cubed.
I hope all this is "deliberate", because you can change if you want to. And
when you do, you will wonder why you didn't do it earlier.
Phil Allison
"William Sommerwanker"
** Bill,
if you were merely a fuckwit
- you would not be even half so bad
..... Phil
William Sommerwerck
> ** Bill,
> if you were merely a fuckwit
> - you would not be even half so bad
And your point is...?
Phil Allison
** You could not have made for me it any better.....
ROTFL
.... Phil
Meat Plow
> "Phil Allison is a Lying Retarded PIG "
I fixed the Subject line and edited your comment to reflect the truth.
No need to thank me.
William Sommerwerck
> to reflect the truth. No need to thank me.
Thank you, anyway.
How many times do we have to tell you, Phil, that we are neither impressed
with nor frightened my your rude remarks?
Aren't you bothered that other people consider you psychotic? And to what
end?
Jamie
Jamie
Mark Zacharias
news:76jap.26428$To7....@newsfe12.ams2...
I am proud to call Geoff Darby, (Arfa) a friend.
Mark Zacharias
Wild_Bill
circuit you're seeing sounds a like the schematic I looked at for the
*Peavey Mace A* series (6, 6L6GC output tubes).
That's sounds like how the schematic was drawn, although I haven't see the
actual circuit layout of that model.. separate resistors were used for each
tube of one pair.. then another pair was wired direct, while the third pair
had 2 more separate resistors shown between those pairs (appearing like the
2 resistors were wired in series between those 2 pairs).
There seem to be numerous similarities in many PV amp model schematics of
the power output sections, but then some specific oddities in a couple of
models' schematics that look out of place (to me, anyway).
One thing that I have discovered recently, is that there are a huge number
of PV amp users, and lots of forum discussions about many modifications
(some that have produced results, and some that don't) and also repairs.
You're probably already aware that many forum discussions wrt electronic
circuits can include unintentional errors and/or other misleading info (this
mod I came up with is the ultimate! for example), so that much of the forum
info needs to be pondered and then either accepted or rejected by one's
better judgement and/or experience.. and compared to the rule: if it werks,
don't fuck with it.
As I've only recently started dabbling in this area, I've noticed one thing
that's prevalent.. practially every component in/on guitars and amps have
been tampered with and replaced, and the majority of reports of the actors
claim that the acts produce amazing results.
--
Cheers,
WB
.............
"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:ZeR9p.55357$XM7....@newsfe18.ams2...
Phil Allison
"William Sommerwanker"
** Bill - you are just another boring usenet wanker, a TROLL and a complete
fuckwit.
D R O P DEAD
Phil Allison
"Mark Zacharias"
> I am proud to call Geoff Darby, (Arfa) a friend.
** My god you must be a desperate poofter to lick the bullshitting fool's
arse in public like that.
Makes YOU into a moronic troll too.
Piss off.
.... Phil
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8t084v...@mid.individual.net...
>
> "Mark Zacharias"
>
>
>> I am proud to call Geoff Darby, (Arfa) a friend.
Why thank you. Mark ! And back atcha :-)
>
>
> ** My god you must be a desperate poofter to lick the bullshitting fool's
> arse in public like that.
>
> Makes YOU into a moronic troll too.
>
> Piss off.
>
>
> .... Phil
>
Such a shame, Mark. Philip is obviously desperate to have someone offer the
same sentiment to him. Must be hard to have everyone thinking that you're a
twat ...
Arfa
Phil Allison
"Arfa Daily"
** Go DROP DEAD
- you ridiculous, fucking FAKE !!!
Michael A. Terrell
Arfa Daily wrote:
>
> "Phil Allison" ?phi...@tpg.com.au? wrote in message
> news:8t084v...@mid.individual.net...
> ?
> ? "Mark Zacharias"
> ?
> ?
> ?? I am proud to call Geoff Darby, (Arfa) a friend.
>
> Why thank you. Mark ! And back atcha :-)
>
> ?
> ? ** My god you must be a desperate poofter to lick the bullshitting fool's
> ? arse in public like that.
> ?
> ? Makes YOU into a moronic troll too.
> ?
> ? Piss off.
> ?
> ?
> ? .... Phil
> ?
>
> Such a shame, Mark. Philip is obviously desperate to have someone offer the
> same sentiment to him. Must be hard to have everyone thinking that you're a
> twat ...
Even his blow up sheep are ignoring him.
--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.
Phil Allison
"Wild_Bill"
>
> One thing that I have discovered recently, is that there are a huge number
> of PV amp users, and lots of forum discussions about many modifications
> (some that have produced results, and some that don't) and also repairs.
> You're probably already aware that many forum discussions wrt electronic
> circuits can include unintentional errors and/or other misleading info
> (this mod I came up with is the ultimate! for example), so that much of
> the forum info needs to be pondered and then either accepted or rejected
> by one's better judgement and/or experience.. and compared to the rule: if
> it werks, don't fuck with it.
** That a good rule to live by....
>
> As I've only recently started dabbling in this area, I've noticed one
> thing that's prevalent.. practially every component in/on guitars and amps
> have been tampered with and replaced, and the majority of reports of the
> actors claim that the acts produce amazing results.
** But they *would* say that - wouldn't they ?
.... Phil
Mark Zacharias
I "plonked" Allison long ago. Not something I do often, either.
Mark Z.
William Sommerwerck
> "William Sommerwanker"
My arrows must be hitting their mark, if I am requested to decease. *
You can always spot the really stupid ones -- they poke fun at my name.
* Have you ever noticed "deceased" is self-contradictory? A "deceased"
person would be someone who's come back to life.
William Sommerwerck
To change the subject... That reminds me of what was arguably Karnak's best
"reading".
Karnak (holding envelope to head): "Sis. Boom. Bah." (opening envelope)
"What is the sound of an exploding sheep?"
Phil Allison
"William Sommerwanker"
** Bill - you are just another boring, NARCISSISTIC usenet wanker,
a TROLL and a complete fuckwit.
Get cancer and fucking DIE
Phil Allison
"Mark Zacharias"
** Lumps of autistic, sub human shit like YOU are a dime a dozen.
And the cause of ALL the trouble on this planet.
..... Phil
Meat Plow
How about wishing death upon me? Am I not good enough anymore?
Meat Plow
I own a 1975 PV Artist 1x15". I bought it back in the mid 80's. PV didn't
deviate much from this design in their later years. I also own a PV MX -
VTX 1x12". Again not much change as for PV the apple never seems to fall
far from the tree.
My current guitar amp config is a PV Tube Fex FX/stereo preamp into a
Studiomaster 700D. That sits on top a PV 4x12" cabinet wired in stereo.
Two stock PV 12's and two Jackson (red cone) 12's. I got the cabinet for
a song and a dance and it sounds as good as any Marshall 1960 cabinet
I've ever played through.
William Sommerwerck
> How about wishing death upon me? Am I not
> good enough anymore?
You're going to have to come up with a remark that really strikes home. I
lucked out.
Meat Plow
Phil is unpredictable in his lashing out. Sometimes the slightest thing
sets him off. Last year he said I should die by a shotgun. I just
wondered if his feelings have changed.
Michael A. Terrell
William Sommerwerck wrote:
>
> ? Even his blow-up sheep are ignoring him.
Karnak always was weird. ;-)
Charles
"Phil Allison" wrote in message news:8su6fb...@mid.individual.net...
"Charles the Puke "
> Until P.A. develops a reasonable command of English
** Whaaattttt ??
My command of the English language is second to none
- you vile, autistic shithead.
Well, there you go Phil! You re-entered the discussion and shot your own
foot off. Vile means repulsive and autistic means withdrawn and shithead
means you!
If you ever went to school, go see them (the headmasters) and demand that
your money (or that of your keepers) be returned.
Michael A. Terrell
Careful, Charles. Phil's favorite 'things' are sheep, and teachers.
Phil Allison
>
>> Until P.A. develops a reasonable command of English
>
> ** Whaaattttt ??
>
> My command of the English language is second to none
>
> - you vile, autistic shithead.
>
> Well, there you go Phil! You re-entered the discussion and shot your own
> foot off.
** Bollocks - I just shot your pointy head right off.
There was absolutely nothing inside but shit.
.... Phil
Charles
You are like three day old fish. Time to get some new material bucko!
http://www.collegehumor.com/article:1724114
Arfa Daily
So, today, I did the mods that the customer was asking for. The value and
type of a coupling cap in the overdrive channel was changed. The input
circuitry was stripped and simplified to standard Fender style - i.e. a 68k
series resistor from input jack to the grid of the first 12AX7, and a 1M
grid return to deck. The fixed negative bias to the grids of the output
tubes was disconnected, and the injection point decked, and the cathodes
were lifted from deck and returned instead via a 100 ohm 4 watt resistor,
bypassed by 100uF.
I also put an additional 1 ohm resistor in the cathode path, so that I was
able to measure the idle current of the output stage. This settled at about
130mA, or just over 30mA per tube, which was exactly what the author of the
mod notes suggested it should be.
I have to say that after carrying out these mods, the amp did seem to have a
much 'smoother' more Fender-like sound, and was still capable of producing
pretty much its full normal output of around 30 watts. I do not have a
sufficiently 'musical' ear to know if the revised sound is what the owner is
looking for, but it did seem to have a very sweet sound, to me. He is
picking it up tomorrow morning, so I guess I should know if he's happy with
it, in fairly short order ...
Arfa
Phil Allison
"Arfa Daily is a Fuckwit "
>
> So, today, I did the mods that the customer was asking for. The value and
> type of a coupling cap in the overdrive channel was changed. The input
> circuitry was stripped and simplified to standard Fender style - i.e. a
> 68k series resistor from input jack to the grid of the first 12AX7, and a
> 1M grid return to deck.
** Does nothing.
> The fixed negative bias to the grids of the output tubes was
> disconnected, and the injection point decked, and the cathodes were lifted
> from deck and returned instead via a 100 ohm 4 watt resistor, bypassed by
> 100uF.
** Ruins the amp.
The cathode voltage now rises up with increasing drive level and at full
drive biases the tubes almost completely off.
This result is gross waveform distortion of the crossover kind - same as
severely under biasing the amp.
Very bad mod.
> I also put an additional 1 ohm resistor in the cathode path, so that I was
> able to measure the idle current of the output stage. This settled at
> about 130mA, or just over 30mA per tube, which was exactly what the author
> of the mod notes suggested it should be.
** So fucking what.
That is only the idle current.
> I have to say that after carrying out these mods, the amp did seem to have
> a much 'smoother' more Fender-like sound, and was still capable of
> producing pretty much its full normal output of around 30 watts.
** Utter bullshit.
As anyone with a functioning scope, dummy load and eyes can see.
.... Phil
Meat Plow
Tone, the sometimes elusive prey in a jungle of equipment. That's what it
all boils down to. My favorite of all time combo amps is the Ampeg VT-22
loaded with a pair of Altec-Lansing 12's. It was my first 100 watter
combo back in the late 70's. If you think a Twin loaded with a pair of
EV SRO's is heavy lift a VT-22 with the Altecs loaded. I ended up trading
it for a 1x15 PV Artist combo around 1982. Still have that old beast.
I'm currently restoring a 1960's Ampeg Jet12. Uses a PP pair of EL84's
for output so it's around 15 watts. Someone has replaced the original
12" Ampeg speaker with a Vox. It's not much to look at but it's one
of those amps that are known for their tone. I've owned it for a decade.
One of those projects you eventually get to.
Hope your customer likes the mods.
Meat Plow
> "Phil Allison is a Fuckwit Troll "
We all agree.
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8t5rid...@mid.individual.net...
I have a functioning scope, and a functioning generator, and a functioning
dummy load, and a functioning power meter, and functioning eyes, and
contrary to what you believe, it most certainly did not distort in any way,
least of all in a "crossover kind" of way, up to full output stage drive. So
it just goes to show what you (don't) know.
And far from "ruining the amp", the owner is actually delighted with it.
Before taking it away, he spent a good half hour here playing into it, and I
can assure you that he is not some kid who doesn't know a transistor amp
from a valve amp from a megaphone. He was actually a very accomplished
musician, and I would take his opinion of the sound of the amp over your
surmised one, any day. In fact, about 3 hours after he took it back home, he
contacted me again to say that he had only just stopped playing into it,
because his fingers hurt, and that there was no comparison to the way it
originally sounded. I'm sure that you will want to come back with another
tirade of ill-considered expletives, but don't waste your time, Philip. I
really don't actually care what you think or believe ...
Arfa
Arfa Daily
"Meat Plow" <mhy...@yahoo.com> wrote in message
news:pan.2011.03...@lmao.lol.lol...
He does. See my other post
Arfa
Phil Allison
> dummy load, and a functioning power meter, and functioning eyes,
** Do you have a functioning DC volt meter?
Bother to measure the cathode voltage ??
Obviously you did NOT !!!
The cathode voltage rises dramatically under increasing drive with the
circuit you have installed.
No brand name guitar amp has a similar mis-behaving bias circuit.
> And far from "ruining the amp", the owner is actually delighted with it.
** Yaaaawnnnnnnnnnnnnnnnnnnnnnnn.....
Guitarists are congenital fuckwits - especially those who come asking for
wacho mods to be done.
Sounds like you and this guitar playing fool are a match made in heaven.
.... Phil
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8t7qj1...@mid.individual.net...
So, like I said. Just goes to show the fuck all that you know. Let's take a
look for a moment, at the Vox AC30, shall we ? One of the most famous amps
using 4 x EL84 ever made. And guess what ? Cathode bias. What was it you
said ? Oh yes. " No brand name guitar amp has a similar mis-behaving bias
circuit." Dopey twat.
Now shut your stupid mouth, Philip, and piss off.
Arfa
Phil Allison
"Arfa Daily is a FUCKING IMBECILE "
>
>> No brand name guitar amp has a similar mis-behaving bias circuit.
>>
>>> And far from "ruining the amp", the owner is actually delighted with it.
>>
>> ** Yaaaawnnnnnnnnnnnnnnnnnnnnnnn.....
>>
>> Guitarists are congenital fuckwits - especially those who come asking
>> for wacho mods to be done.
>>
>> Sounds like you and this guitar playing fool are a match made in heaven.
>>
>
> a look for a moment, at the Vox AC30, shall we ? One of the most famous
> amps using 4 x EL84 ever made. And guess what ? Cathode bias.
** More BLATANT misrepresentation from the lying pommy cunt - only
possible because the LYING POMMY CUNT refuses to post under the other
person's words as usenet etiquette REQUIRES.
> " No brand name guitar amp has a similar mis-behaving bias circuit."
** The cathode bias circuit in the Vox AC30 does not misbehave - but the
four EL84s do run very hot and the PSU is way bigger than fitted in the
Peavey Classic 30.
The cathode resistor used in an AC30 is not 100 ohms.
..... Phil
Wild_Bill
some volume?
--
Cheers,
WB
.............
"Meat Plow" <mhy...@yahoo.com> wrote in message
news:pan.2011.02...@lmao.lol.lol...
Wild_Bill
Yanking some chains?
Bollucks/dumbfoundness
--
Cheers,
WB
.............
"Phil Allison" <phi...@tpg.com.au> wrote in message
usenet etiquette REQUIRES.
Phil Allison
"Wild_Bill"
** Piss off - you stinking FUCKWIT TROLL
Wild_Bill
I'm not the one repeatedly posting witless and senseless reactions to other
generally well-meaning posts.. that's only you.
While you're studying the usenet etiquette guidelines, and stating/spouting
the references, you might see some suggestions wrt your everyday posting
habits.
Eat shit 'n die, Phil.. you don't matter.
--
Cheers,
WB
.............
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8t8mdn...@mid.individual.net...
>
Designer watches, handbags discount prices PayPal
Phil Allison
"Wild_Bill"
** Fuck off - TROLL
Wild_Bill
your small mind Phil.
Go piss upwind if you can work up a stream
--
Cheers,
WB
.............
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8t8phc...@mid.individual.net...
>
win a free ipod
Meat Plow
> That looks like a nice collection of gear.. but what do you do when you
> want some volume?
>
> --
> Cheers,
> WB
> .............
LOL!
Wild_Bill
http://www.guitarpartssite.com/Allparts-PK-0132-023-p/PK-0132-023-AP.htm
Or, eBag item # 330463361907
--
Cheers,
WB
.............
"Meat Plow" <mhy...@yahoo.com> wrote in message
news:pan.2011.03...@lmao.lol.lol...
Meat Plow
> These may help..
>
> http://www.guitarpartssite.com/Allparts-PK-0132-023-p/PK-0132-023-AP.htm
>
> Or, eBag item # 330463361907
>
> --
> Cheers,
> WB
> .............
Believe or not, there is a reason to have a lot of headroom in a SS
guitar amp. I get all my sustain and crunch from the PV Tube Fex's 2 x
12AX7's. I've had several multi-fx units but that one even though its a
decade or more old beats them all hands down.