Nakamichi PA-5 and PA-7 Design Help Requested

[dude2010]

Originally Posted by dggs

I have my PA-7 for almost 20 years. Have always been wondering how easy/difficult/possible it is to convert it to balanced input. Thanks Apogee for posting the input stage schematics. Can I just disconnect C102 and feed negative input to R108(?) (2.21K) ? Any comment would be appreciated!

Any answer to this??

[Lars Nielsen]

Originally Posted by dude2010

Any answer to this??

No. You can not short C102. C102 is the feedback..

The best upgrade to these amplifiers is to short C102, it will then be dc coupled. I did that with my own, and the sound came to another level.

[dude2010]

Originally Posted by Lars Nielsen

No. You can not short C102. C102 is the feedback..

The best upgrade to these amplifiers is to short C102, it will then be dc coupled. I did that with my own, and the sound came to another level.

You can't short it... But you did short it!?? Did I miss something here?
But great! Tell us more about your modds!

[Lars Nielsen]

Originally Posted by dude2010

You can't short it... But you did short it!?? Did I miss something here?
But great! Tell us more about your modds!

Sorry.. You can not disconnect C102..

If you short C102, the amp will be DC coupled.

My mods are described in another thread.. just search

[Brent Powers]

I see Apogee is exploring the whole Stasis thing, too, only in a far more intelligent and informed manner than I am. I would hope to learn as much as I can about these amps, since I, too, have recently developed a Stasis jones, only know zip about circuitry and hands on design, upgrades, etc., but since you chappy's are on it here, I'll just hang out and lurk, ask dumb questions, hopefully get to the point where I can even understand what you are talking about! Also interested in just how much of this is Pass 9000 and how much Nakamichi. I cannot afford Threshold to do any a/b listening tests. I've been pulsing Nelson San in emails and I must say he's been quite patient but I think this is the better path to Wisdom and Understanding, and it will spare the gent my crazy missives.

BP