Slightly odd output stage configuration. Thoughts ?

"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.


I have a functioning scope, and a functioning generator, and a functioning
dummy load, and a functioning power meter, and functioning eyes,
Click to expand...
** 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.
Click to expand...

** 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
 
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:8t7qj1Fk54U1@mid.individual.net...
"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.


I have a functioning scope, and a functioning generator, and a
functioning 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
Click to expand...
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
 
"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.


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.
Click to expand...
** 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."
Click to expand...
** 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
 
That looks like a nice collection of gear.. but what do you do when you want
some volume?

--
Cheers,
WB
..............


"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2011.02.28.17.53.52@lmao.lol.lol...
On Sun, 27 Feb 2011 19:15:34 -0500, Wild_Bill wrote:


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.







--
Live Fast, Die Young and Leave a Pretty Corpse
Click to expand...
 
Pulling some legs Phil?

Yanking some chains?

Bollucks/dumbfoundness

--
Cheers,
WB
..............


"Phil Allison" <phil_a@tpg.com.au> wrote in message

usenet etiquette REQUIRES.
 
I'm really disappointed with your terse reply, maybe you could elaborate.

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" <phil_a@tpg.com.au> wrote in message
news:8t8mdnFmt8U1@mid.individual.net...
Designer watches, handbags discount prices PayPal
Click to expand...
 
That uncanny ability to incite or anger, exists only within the confines of
your small mind Phil.

Go piss upwind if you can work up a stream

--
Cheers,
WB
..............


"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:8t8phcF8ncU1@mid.individual.net...
win a free ipod
Click to expand...
 
On Wed, 02 Mar 2011 23:37:34 -0500, Wild_Bill wrote:

That looks like a nice collection of gear.. but what do you do when you
want some volume?

--
Cheers,
WB
.............
Click to expand...

LOL!

"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2011.02.28.17.53.52@lmao.lol.lol...
On Sun, 27 Feb 2011 19:15:34 -0500, Wild_Bill wrote:


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.







--
Live Fast, Die Young and Leave a Pretty Corpse
Click to expand...




--
Live Fast, Die Young and Leave a Pretty Corpse
 
These may help..

http://www.guitarpartssite.com/Allparts-PK-0132-023-p/PK-0132-023-AP.htm

Or, eBag item # 330463361907

--
Cheers,
WB
..............


"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2011.03.03.15.39.28@lmao.lol.lol...
On Wed, 02 Mar 2011 23:37:34 -0500, Wild_Bill wrote:

That looks like a nice collection of gear.. but what do you do when you
want some volume?

--
Cheers,
WB
.............


LOL!


"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2011.02.28.17.53.52@lmao.lol.lol...
On Sun, 27 Feb 2011 19:15:34 -0500, Wild_Bill wrote:


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.







--
Live Fast, Die Young and Leave a Pretty Corpse






--
Live Fast, Die Young and Leave a Pretty Corpse
Click to expand...
 
On Thu, 03 Mar 2011 16:07:06 -0500, Wild_Bill wrote:

These may help..

http://www.guitarpartssite.com/Allparts-PK-0132-023-p/PK-0132-023-AP.htm

Or, eBag item # 330463361907

--
Cheers,
WB
.............
Click to expand...
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.

--
Live Fast, Die Young and Leave a Pretty Corpse
 
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