NAD 3020 restoration

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Check there's nothing living in it, and the voltage across the speaker terminals is about zero at minimum volume (and no input signal).

Then fire up and see what it sounds like. I've one running all original components, sounds fine. The pots and switches will probably need a clean, IPA is OK.

There's a site here with tips for replacing various caps, both in the signal path and PSU, a search of this forum will turn up IIRC the bias settings and setup method (or clicky here for the service manual) and the schematic is online in a few places.
 
Hi

I also own a NAD 3020. Nowadays it is playing in my office. (ZEN is responsible for expelling it out of my home). I have made a couple of small changes:

1. Replaced filter capacitors: I mounted two 10,000 uF (instead of 4x2200 uF)
2. Replaced ordinary trim pots with multiturn ones. Readjusted until I got almost zero DC offset. Read this: http://www.tnt-audio.com/clinica/bias_e.html
3. Added small heatsinks on the driver transistors (this is not necessary, but I thought it to be a good idea)
4. Replaced input electrolytic caps with MKS caps. These are much bigger in size, however it is possible to mount them.
5. Cleaned all switches and potentiometers with contact spray.

Hope this helps

Vix
 
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