Is it valve, or is it SS?
 

I have this little battery powered guitar practice amp, made by
Pignose. It sounds amazing - a bit like a Marshall 100 valve amp in
fact, and I could never work out why. These things are used by plenty
of big names on-stage, as well as plenty more who won't own up to it.

Anyway, today I had to take the cover off to fix something and I found
the reason for the meaty sound. It is a mini solid state valve amp

http://81.174.169.10/odds/pignose.jpg

Who'd a thought it?

d

--
Pearce Consulting
http://www.pearce.uk.com

Is it valve, or is it SS?
 

"Don Pearce"

I have this little battery powered guitar practice amp, made by
Pignose. It sounds amazing - a bit like a Marshall 100 valve amp in
fact, and I could never work out why. These things are used by plenty
of big names on-stage, as well as plenty more who won't own up to it.

Anyway, today I had to take the cover off to fix something and I found
the reason for the meaty sound. It is a mini solid state valve amp

http://81.174.169.10/odds/pignose.jpg

Who'd a thought it?



** Dunno just what this Don Dude's angle is here - but that amp module
uses modern Silicon transistors.

So, it must be a fairly recent of " Pignose Technology" ( I use that term
very loosely) .

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.



Pearce Consulting


** Consult your Doctor before swallowing what this man says ......





....... Phil

Is it valve, or is it SS?
 

On Mon, 26 Feb 2007 23:04:51 +1100, Phil Allison wrote:

snip

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.



Wow.... that brings back some memories.
Fastest fuse on three legs!
Did they use the AC128 or the OC81? Just interested - IIRC the AC128 wasn't
as easy (for me) to get hold of. The AC127 was bad enough.

--
Mick (Working in a M$-free zone!)
Remove blockage to use my email address
Web: http://www.nascom.info & http://mixpix.batcave.net

AC128 (was: Is it valve, or is it SS?)
 

"mick" wrote
On Mon, 26 Feb 2007 23:04:51 +1100, Phil Allison wrote:

snip

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.



Wow.... that brings back some memories.
Fastest fuse on three legs!
Did they use the AC128 or the OC81? Just interested - IIRC the AC128 wasn't
as easy (for me) to get hold of. The AC127 was bad enough.

Yeah, the AC128 was the first transistor I _ever_ played with. I was about 9.
I had been given a kids' "Ladybird" book about basic electronics,. and it
had a circuit for an astable multivibrator to flash 2 6V bulbs alternately,
using 2 AC128 transistors. The book must have been a bit dated, because that
was not a time when germanium transistors were still prevalent. It would have
been about 1980. Anyway, the circuit worked, and provided a fair bit of
entertainment for the young me. I jacked up the frequency and made it drive
a loudspeaker to get sounds of various (and, with a pot, variable) frequencies.

I still remember what the AC128 looked like, with its thin wire leads and its
red dot (by the emitter, IIRC).


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie

Is it valve, or is it SS?
 

On Mon, 26 Feb 2007 21:22:13 GMT, mick wrote:

On Mon, 26 Feb 2007 23:04:51 +1100, Phil Allison wrote:

snip

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.



Wow.... that brings back some memories.
Fastest fuse on three legs!
Did they use the AC128 or the OC81? Just interested - IIRC the AC128 wasn't
as easy (for me) to get hold of. The AC127 was bad enough.

All silicon, I'm afraid.

d

--
Pearce Consulting
http://www.pearce.uk.com

AC128 (was: Is it valve, or is it SS?)
 

On Mon, 26 Feb 2007 21:34:51 -0000, "Fleetie"
wrote:

"mick" wrote
On Mon, 26 Feb 2007 23:04:51 +1100, Phil Allison wrote:

snip

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.



Wow.... that brings back some memories.
Fastest fuse on three legs!
Did they use the AC128 or the OC81? Just interested - IIRC the AC128 wasn't
as easy (for me) to get hold of. The AC127 was bad enough.

Yeah, the AC128 was the first transistor I _ever_ played with. I was about 9.
I had been given a kids' "Ladybird" book about basic electronics,. and it
had a circuit for an astable multivibrator to flash 2 6V bulbs alternately,
using 2 AC128 transistors. The book must have been a bit dated, because that
was not a time when germanium transistors were still prevalent. It would have
been about 1980. Anyway, the circuit worked, and provided a fair bit of
entertainment for the young me. I jacked up the frequency and made it drive
a loudspeaker to get sounds of various (and, with a pot, variable) frequencies.

I still remember what the AC128 looked like, with its thin wire leads and its
red dot (by the emitter, IIRC).


Martin

For me it was the OC71. ******* cost about thirty bob, and it lasted
somewhere around a minute. I learned about biasing after that.

d

--
Pearce Consulting
http://www.pearce.uk.com

Is it valve, or is it SS?
 

Don Pearce wrote:

I have this little battery powered guitar practice amp, made by
Pignose. It sounds amazing - a bit like a Marshall 100 valve amp in
fact, and I could never work out why. These things are used by plenty
of big names on-stage, as well as plenty more who won't own up to it.

Anyway, today I had to take the cover off to fix something and I found
the reason for the meaty sound. It is a mini solid state valve amp

http://81.174.169.10/odds/pignose.jpg

Who'd a thought it?

Yes, it's the colouration the transformers give to the sound !

Have you seriously only just realised that ?

Graham

Is it valve, or is it SS?
 

Phil Allison wrote:

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.#

Have you lost your brain ?

Pignoses never used germanium devices.

Graham

Is it valve, or is it SS?
 

On Tue, 27 Feb 2007 10:24:14 +0000, Eeyore
wrote:



Don Pearce wrote:

I have this little battery powered guitar practice amp, made by
Pignose. It sounds amazing - a bit like a Marshall 100 valve amp in
fact, and I could never work out why. These things are used by plenty
of big names on-stage, as well as plenty more who won't own up to it.

Anyway, today I had to take the cover off to fix something and I found
the reason for the meaty sound. It is a mini solid state valve amp

http://81.174.169.10/odds/pignose.jpg

Who'd a thought it?

Yes, it's the colouration the transformers give to the sound !

Have you seriously only just realised that ?

Graham

Of course not - I have always known about transformers, and
particularly their use in guitar amps. What I hadn't realised was that
this little practice amp had them - it explained a lot.

d

--
Pearce Consulting
http://www.pearce.uk.com

Is it valve, or is it SS?
 

On Mon, 26 Feb 2007 23:04:51 +1100, "Phil Allison"
wrote:


"Don Pearce"

I have this little battery powered guitar practice amp, made by
Pignose. It sounds amazing - a bit like a Marshall 100 valve amp in
fact, and I could never work out why. These things are used by plenty
of big names on-stage, as well as plenty more who won't own up to it.

Anyway, today I had to take the cover off to fix something and I found
the reason for the meaty sound. It is a mini solid state valve amp

http://81.174.169.10/odds/pignose.jpg

Who'd a thought it?



** Dunno just what this Don Dude's angle is here - but that amp module
uses modern Silicon transistors.

So, it must be a fairly recent of " Pignose Technology" ( I use that term
very loosely) .

The earlier, almost famous and better sounding examples used Germanium
devices.

AC127 /128 IIRC.


What I mean is that although the amp is solid state, it uses a
topology more normally associated with valve amps. As such it has many
of a valve amp's characteristics - particularly the curved transfer
function, soft limiting and core saturation. Those are the things that
are heavily exploited in guitar amps to give thickness and weight to
the sound.

I'd never had the cover off this before and I was surprised not to
find a conventional tranny amp (even an IC amp) with some diodes
across the input to give it a bent transfer curve. This is a much more
expensive and better way to achieve the desired effect.

Of course I recognise that this was a conventional way to implement a
"Hi Fi" SS amp back in the sixties - indeed I built a few myself. But
when PNP/NPN matched pairs were a serious proposition and the op-amp
circuit was better understood and accepted, this method died a rapid
and largely unmourned death.



Pearce Consulting


** Consult your Doctor before swallowing what this man says ......





...... Phil



Whatever.

d

--
Pearce Consulting
http://www.pearce.uk.com