SS poweramp with soft clipping on FET's.

[petemoore]

Here, in Russia we say that any new thing is a well forgotten old one $)
  It'll be a while before I forget this one, this seems to make even more sense, the more time goes by.

[trevize]

thank you medved. Did you build the amp? how does it sound?

i'm probably going to try a build of it, it looks far more interesting than the tdaxxxx amps.
it would probably make a good power amp for my jensenp10r.

[Medved]

It'll be a while before I forget this one, this seems to make even more sense, the more time goes by.

I can't translate exactly, but sounds great

thank you medved. Did you build the amp? how does it sound?

Unfortunatly, no. I have practically no time- my learning, work and a rather complicated tube project leave me no chance to complete this amp now. May be in two or three months- at the end of summer.

i'm probably going to try a build of it, it looks far more interesting than the tdaxxxx amps.
it would probably make a good power amp for my jensenp10r.

Ok. I'll try to help, if you have any questions.
It's very simple in fact

[Medved]

Did you build the amp? how does it sound?

I build it. Here is the schema:

2p904a<-->2sk1058
kd521a<--> any silicon diode
With 2sk1058 there is no need in D5-D8
Sound:
http://webdrive.reborn.ru/egorov/Power/pamp6.rar
Usa Strat-->FetTwin min.gain, max vol-->poweramp-->2/3 closed back 1*12 Vintage30 cab-->Shure 565sd--> Audigy.
Output power up to 25-30W at peaks (meander). Nearly 20W with soft clipping.

[lovric]

madved,

it's surf and shadows sounds!

what is 'fet twin min'? anything simmilar to runofgroove stuf?? i have my preamps on 9V, i guess it's not a sin if they overload the amp. (your info on gain is somwhere in the discussion, i have to reread... )

i guess it's very loud when clipping starts...

i am a beginner. i'm wondering if output power could be diminished? is it possible just to make

(V1,V2)=12V and (V+)=15V

or (12,9)

now, since i can't design, i wish it does not have this 'floating' output so i could make a preamp out of it and plug it into speaker cab and what not. never mind.

ps. and, please don't kill me 

[KerryF]

Do you have the soundclip in WAV or MP3 or something, rather than RAR?

[swt]

i can get bf245 in here (patagonia, argentina), and i use them for almost everything. as far as i remember the c version is the low cutoff one, the a version has higher one. i can send you some bf245c and bf245a if you want to build that amp like it is...

[G-G]

I'm not Medved? but i can reply on some simple questions.
2lovrik

1. Medved means minimum gain of his FET Twin preamp.
2. Yes, its possible to diminish output power with changing supply voltage and wuth lower output power you can use other type of FET. For example by using russian KP903a and lower supply voltage you can get ~5W amplifier.
3. I don't understand your last problem, may be my english is so bad.

2call1800ksmyazz
There is an mp3 soundclip, RAR is just archive format. You must decopmress it.

[Medved]

what is 'fet twin'?

http://www.gtlab.net/gtlab2/readarticle.php?article_id=51

i guess it's very loud when clipping starts...

Yes, it's loud for home.

i am a beginner. i'm wondering if output power could be diminished? is it possible just to make
(V1,V2)=12V and (V+)=15V
or (12,9)

Yes, it's possible with some minor changes of resistors values.

now, since i can't design, i wish it does not have this 'floating' output so i could make a preamp out of it and plug it into speaker cab and what not. never mind.

It's impossible in my poweramp.

i can get bf245 in here (patagonia, argentina), and i use them for almost everything. as far as i remember the c version is the low cutoff one, the a version has higher one. i can send you some bf245c and bf245a if you want to build that amp like it is...

bf25c cutoff: -3.2..-7.5
bf24a cutoff: -0.4..-2.2

[lovric]

2G-G
1. my problem is the lack of knowledge really
that question represents my wishfull thinking.

2. can you give me the specification of KP903a so i could search for a substitute.

in one of the topics this year somebody asked how to simulate distortion of push-pull stages with fets (or with anything 3-legged) in a preamp meant for recording. the closest examples were on analogalchemy.

i did notice medved wrote that 'floating' of the output stage is impotant to this design and so could never be transformed the way i thought.

[G-G]

I think you will not find KP903 analogue. But you can use 2sk1058 with lower voltage power supply or something form this family. 12/9 V power supply gives you about 2.5W in soft clipping and about 3W in hard (square) and you will need to replace 2k7 resistors on 1k ones.
If you need micro-PA in a box for spikersimulation and so on I can recommend you to read this article. It's on Russian, but scheme is simple and understandable on all languages. You can use only tube part of scheme in you device.

[lovric]

c6acu6a G-G for the advice

browsing through the links you sent i have found http://www.sugardas.lt/~igoramps/article29.htm

it's a curiosity to share.