Help upgrading Capacitors in Myryad hifi Amplifier

[Perrin21]

I have a Myriad MA240 power amplifier i would like to replace and upgrade the main capacitors inside. However, the capacitors are 22mm wide and there is no room for a wider capacitor which appears to severely limit the choice i have for replacements. The capacitors that are inside currently are Nichicon LS 63V 4700uF . Can anyone recommend a significantly better capacitor to replace the 7 inside? Assume for now that money is no object and size is the main restriction. What do you suggest that has better specifications?

I am also looking for some suggestions on other upgrades for this amplifier as ive noticed there are some poor quality components inside that could be easily replaced such as the Potentinometer switches (1 already crumbled when i tried gently adjusting the bias).  Who makes the highest quality 5mm 500R 3 leg potentiometers?

Here are some pictures of the board.

[Haenk]

I doubt there is something significantly better out there (Nichicon is one of the top brands). If they are not leaking and still within tolerance, there is (IMHO) no point in replacing them. If you really need to replace them, just chose a top brand (ELNA, Nichicon, Chemicon etc.), I assume the engineers designing this amp did their job and installed enough capacity…
The pots are "OK"ish, the "crumbling" seems to be just the outer part to make it look nicer, I assume they still work fine. Replacing them will not improve sound. Adjusting will.
As for the other parts, I only see quality parts in there, changing the caps for "audio grade" will probably do next to nothing. If you really want to toy around, changing the OpAmp will influence the sound, "better" is really more like "I like it better".

[Perrin21]

Hi, thanks for your reply.  I have been comparing Nichicon capacitors (mine field it seems).  I am considering the UKW 63V 4700 22x50 size or the LS 63V 4700 22x50 capacitors.  The UKW claim to be for audio but the specs on the LS appear better as 3000 hours.  what are your thoughts on these?

As there are some additional capacitor slots for the MA360 3 channel version of the amp that shares the board, is there any benefit to filling those slots too and increasing the total capacitance?  What would the benefit or disadvantage be to that?

[tooki]

Essentially all claims about a particular electrolytic being better for audio are just snake oil. Audio doesn’t have magic properties. Electronic circuits need components with particular characteristics, and given how electrolytic capacitors work, there’s no real way for them to differ in audio-specific ways. (The least implausible explanation I’ve heard is the audio caps having an ESR that is flat through audio frequencies, making them suitable for filters.)

So another vote here for “if they are still in spec, and haven’t leaked, don’t replace”. You’ll be spending time and money for nothing.

P.S. bear in mind that the original manufacturer also had access to the “audio grade” components. So if they didn’t use them, they either found them to not make any difference at all, or to make one so tiny as to not be worth the price. But my hunch is that an amp built well enough to use nichicons probably wasn’t worried about a few more cents, so my guess is that they chose the ones that work best in their product.

[Haenk]

Again, if the installed caps are not broken, there is no need to replace them.
Installing larger/additional caps has no downside, but might help if you are running your amp at the limit. Which you really don't want to do at all.
*If* you decide to install other caps (for whatever reason I can't imagine), I'd always go with longlife components in the power section, no need to use expensive audio parts there.
Again, don't do it, the amp is fine as it is