NAD 3020

[crazymexican]

Hi there
I'm just getting into the DIY wagon after a couple of small projects in the past

Anyway I got this me this little project of recapping a NAD 3020, I know this fellow has been the subject of countless threads ( I found the service manual in one of those older threads).

Despite that I wanted to ask directly do you guys thinks there's a specific spot ( or spots) where the investment in boutique caps will pay off, or the difference against using your regular caps will be negligible.

regards

Francisco

[Richard Ellis]

In the "tube-world" the "spendy ones" are used between stages (Driver & power). Peruse thru your schematic to find the interstage caps...if there are any? Most SS gear now is "direct".....void of interstage caps.


__________________________________________________ _____Rick......

[Jay]

Expensive caps only for "cost-no-object" project, where you want to invest more for little improvement. I'm in a position to use above average amps, so going with expensive caps is fine with me, but never too expensive.

NAD 3020 is for example below average for me, thus I will not use Black Gate, Cerrafine and the like here. Because if I want better sound, I will change the amp, not the cap.

For small capacitance, MKP is never too expensive, only the size is a problem. NP/BP is acceptable for me, even for a better amp than the NAD.

Start with good schematic, and worry less about boutique caps. Power supply is very important, and big caps are expensive. Nippon-Chemicon is a cheap non-audiophile brand but often outperform audiophile caps.

You can also buy expensive caps for investment. You can change the schematic later with better one and use the old caps.

[sakis]

to someone that replace an average of 5.000 lytics per year that is a hell of an expression !!!!! : boutique caps !!!

Trying to make a choice between boutique caps or not is not the wise thing to do . The best approach will be to make a study find the places and areas that you can actually beef capacitance add decoupling and bypass .

A blind replacement of the same value capacitors will probably bring the amp to more or less original condition but since you are going to spend the money anyway why not upgrade a couple of things .

Kind regards
sakis

[crazymexican]

Well I haven't had time to take a deep look into the amp schematic yet.
but here's what I am planing on doing:
1.- replace the cap in the Power supply with a higher value ones.
2.- ]find the caps in the phono section and those Directly in the signal pass and try to find a good quality replacement (but keeping the $$$ in mind, as this amp is going to be used while I save up the coin for a NICE replacement or until I get soldering iron happy and start building something better)
3.-every other electrolytic in the circuit gets replaced with "regular" caps

How does that sound???

[planet10]

Originally Posted by crazymexican

1.- replace the cap in the Power supply with a higher value ones.

Be very careful about doing that in the regulared supply, I have successfully put massive amounts on the ynregulated power stage supply.

dave

[Jay]

Originally Posted by crazymexican

Well I haven't had time to take a deep look into the amp schematic yet.

For an old amp (it uses slow transistors), the 3020 is very good. If you like the 3020 and want to try other design, try the SSA. Feedback is also applied to emitter through low impedance path, except that it is symmetrical, lower part count and can use fast transistors.

With 3020 you have 2x1uF in the normal input path, and 47uF bootstrap cap. In the feedback, 1000uF in parallel with 100n.

[crazymexican]

well I just finished ordering my caps from mouser, just decided to use chemicon all over. I hope to get this one done during the weekend.

[arturo1]

All the electrolytic capacitors will be dry and should be changed, the mains cable can usefully be changed for a thicker multi strand type, this mod improved my original 3020 back in the early 80s'. If you want to use the phono input, change the mylar/ceramic capacitors for polystyrene types, very large improvement !