any experts mind taking a look at this for me?

vpolineni · « **on:** 21 Oct 2004, 05:22 am »

all you experts out there... i'm interested in this preamp:
http://www.yushang-audio.com/english/Our%20Products/9-0.htm

the website is very informative and goes into detail about the proprietary circuit used for this preamp:
http://www.yushang-audio.com/english/Related%20Technology/Srpp.htm

Now it's all gibberish to me.. but I know there are a lot of experienced designers/modders/diy'ers here.. I'd appreciate you input on it. thanks.

JohnR · « **Reply #1 on:** 21 Oct 2004, 12:31 pm »

What is it that you want to know?

SRPP has been around forever. I looked only briefly at their text (their site doesn't work too well in my browser). As I recall, some folks don't like it, claiming that it's a cathode follower in another guise ( I see their point); otoh I believe it's been used as a driver stage in renowned SET amps (I think they might have said that actually). I once built a headphone amp that used an SRPP topology, IIRC, the friend I gave it to loves it.

http://www.tubeaholic.com/archives/page.view?filename=/archives/ccs/index.html

But, when it comes down to it, no circuit diagram is going to tell you whether you will like it in your system - ?

Occam · « **Reply #2 on:** 21 Oct 2004, 12:50 pm »

Indeed, the SRPP is an excellent circuit, if its operatiing point is tuned for driving a known impedance, which is not the case when used as the output of a preamp.... In the case of a driver for a poweramp, it 'knows' exactly what the charateristics of the load circuit , and techniques such as THD nulling can be applied, if that is one's intent.
An SRPP used as the output of a pre (if that is how this pre works) is at best, a crapshoot; it might work beautifully, it might not, and would be highly dependant on the following (unknown) circuitry.

Regards,
Occam

JoshK · « **Reply #3 on:** 21 Oct 2004, 01:46 pm »

What does SRPP stand for?

Occam · « **Reply #4 on:** 21 Oct 2004, 02:02 pm »

Quote from: JoshK

What does SRPP stand for?

Shunt Regulated Push Pull

http://www.tubecad.com/may2000/

http://digilander.libero.it/paeng/non_linear_behaviour_of_the_srpp.htm

[Edit] PS - Vasu, Iff'n you keep posting that you only want expert's opinions, I'm afraid I'll have to stop posting....

vpolineni · « **Reply #5 on:** 21 Oct 2004, 02:03 pm »

thanks for the input.. i just wanted to get a general idea of how it's designed.. i know that ultimately the definitive test would be how it sounds in my system.

vpolineni · « **Reply #6 on:** 21 Oct 2004, 07:13 pm »

Paul,
When I say "expert", I mean in terms of my own knowledge-so that includes just about everyone.

thanks for your input.