Did your replacement caps include the 30+ electrolytic caps previously mentioned?[/QUOTE said:
Those NAD amps are not difficult to work on in that things are relatively accessible and there is not an overabundance of parts.
To answer your question, yes I replaced every electrolytic but probably wasted my money on new main filter caps. I went through a similar exercise later with some low wattage power amps with only 17 caps per amp in their case. The first one got new filter caps even though the originals were good but it was such a pain in the butt adapting new ones to fit that those in the other amps were left alone. Plus new ones were about $25 per pair. The smaller caps cost maybe $10 all together and took a few hours work to put in so I went ahead with that.
Some advice given to me when I embarked on re-capping an APT Holman pre-amp, was don't waste money on anything other than general purpose capacitors. That bit of wisdom came from someone with the APT Corporation while that pre-amp was in production. No benefit at all to installing a $1.50 capacitor when a 35 cent one will do.
Since I could notice no difference in sound, radical or otherwise, I no longer jump right into cap replacement unless something's wrong at the get go.
But, the process does have sort of a Zen like quality. Similar to knitting I think.
If new caps are on your agenda, don't underestimate the time needed to properly unsolder the old components on the board. Lifting traces is no fun and correcting boo-boos with jumpers can be unsuccessfully messy.
Having learned that what is printed on a parts list or schematic, may not be what you get on a board (especially with NAD), my habit became examining one by one, each item slated for removal then write down the numbers that are on it. Once I've done that, I put a felt pen dot on that part to tell me it's been recorded. That also helps when installing new parts. See a dot, it gets pulled - no dot, already replaced.
There is a side benefit in doing this to a NAD device. You will get to see close up and personal the failed or about to fail old NAD solder connections that they're famous for.
If you proceed, it would not hurt to document your work on paper. If the amp passes to a new owner, they'll have a record of what old component got replaced and with what new one. Chances are that you will be substituting capacitors with a higher voltage rating that what it replaces. That info might be useful to someone down the road who winds up with your amp.