Ian and Mooley, I put the old resistors back. It dialed right in. I'm playing it now and it sounds fine. Sorry if I wasted your time. You guys have probably have forgotten more about this stuff than I know. My approach to these projects may be flawed as well. I replaced resistors and diodes while recapping. How would you go about an older project like this? Anyway, thanks for your time!
Its all a learning curve
As a general rule semiconductors don't deteriorate. Things such as older opamps (IC's... operational amplifiers) can often be replaced with more modern devices. Electrolytic caps do age but tbh probably not as much as some make out. Heat is the big killer for electrolytic caps. Beyond that and I would probably go over the all the soldering on the PCB. Dry joints are common and not always obvious such as here, last pictures post #1
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
Thanks
No electroylitics changed on that one and I still have an original (electrically) 1978 ish Sony cassette deck and Tuner. Component wise all original. I'm not trying to say caps don't fail but its not always as much a problem as its made out to be. Problems in older equipment tend to be more physical issues, drys, noisy controls, in fact presets can go noisy and intermittent.
Enjoy the amp
No electroylitics changed on that one and I still have an original (electrically) 1978 ish Sony cassette deck and Tuner. Component wise all original. I'm not trying to say caps don't fail but its not always as much a problem as its made out to be. Problems in older equipment tend to be more physical issues, drys, noisy controls, in fact presets can go noisy and intermittent.
Enjoy the amp
I don't really quite get R643/644 being 2.2K
Sorry to insist. Is this some typo or what?
Attachments
Well, you are correct. There are holes in the pcb for the resistors but there is a jumper instead. Also I never found the little caps on the inputs.
That's pretty normal on a lot of commercial gear where the basic product may be aimed at different markets. Or the design changed in production and it was found they could eliminate those parts thus saving costs.
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