NAD 3020 - faulty but is it worth fighting for it?

[JonSnell Electronic]

"My further concern is that if I ever need to change these two caps what values should I uses, as from what I can gather while it's acceptable to use slightly higher value caps it's not to use lower value. So let's say if I follow the manual and replace 100uF 10V (installed) with 47uF 10V (suggested) and if it was a printing mistake in the manual I could mess up things, could I? "
You wouldn't notice and no you won't break it.

 

[Andris L]

And now you have one of the most musical amps made. I still got mine, on the shelf, i am playing with more expensive equipment. I love the sheer musicality of the 3020, it is hard to find elsewhere.

I absolutely love the sound of it that's why I wanted to make it right so badly. 🙂

Use Servisol Switch Cleaner or if they are really bad 3in1 Lawnmower oil. Yes, it works a treat!
C531 and 533 are the main ones to change!

Thanks Jon!

And I already replaced the C531 & C533 so all good. 😉

 

[Ian Finch]

According to the manual the capacitor values should be:
C513 - 47uF 10V
C514 - 47uF 10v
C517 - 47uF 25v
C518 - 47uF 25V
C519 - 47uF 10V
C520 - 47uF 10V


but as per my previous post the capacitor values installed are:
C513 - 47uF 16V
C514 - 47uF 16v
C517 - 47uF 25v
C518 - 47uF 25V
C519 - 100uF 10V
C520 - 100uF 10V

So after all the sweat, it was NAD crack-up syndrome, after all 😀
It was Jaycee who suggested this back in #6 anyway. I can't recall how many 3020s I've seen with this fault and there are still so many of them out there lumbered with it and of course, the dried-out caps.

FWIW, you can use higher voltage rated caps than the spec. suggests as long as they fit without stressed leads. These are mostly signal coupling applications where the ultimate in low ESR is not required but low leakage is desirable. Frankly, experience shows that low voltage caps fail sooner and I make it a rule never to use anything under 16V rating in Audio. I note that many commercial audio products have come even from the factory with 16, 25 or even 35V rated electrolytics in lieu of 10V specified. For signal it makes no odds and will most likely have a longer lifetime, should the amp. survive another 30 years.

Meantime, congrats on your repair. Now, make certain it will stay that way by judicious tightening of the socket mounting to restrict mechanical movement and make certain there is some strain relief in the positioning of your cables.
OK, now you can sit back and enjoy 🙂