[jules]

I'd like to replace some PS caps on several different pieces of equipment that currently boast Nover "Audio Grade" capacitors in their power supplies, along with a number of smaller Nover's in other positions. The smaller caps are simple enough to replace and I'll probably use Elnas and a few Black Gates I'm lucky enough to have kept.

The PSs are different. The diameter of the space allowed for these caps is quite small which is limiting my options. A Nover 10,000uF, 50V, 85C cap. has a diameter of 30mm. A Nichicon of the same specs, would be the simplest option BUT a Nichicon gold, 10,000uF, 63V has a diam. of 40mm, which just isn't going to fit when there's a bank of 6 nested together. 

I'm more than a little skeptical about the ability of Nover to pack the rated capacity into something that is half the volume of an equivalent Nichicon but that's beside the point.

The problem here is board space, so does anyone have suggestions as to replacement caps that are relatively tall and narrow to fit a 10,000, 50V, 85C on a 30mm diam footprint and a 3,300uF, 63V, 85C cap on a 25mm diameter footprint [without breaking the bank]?

[richidoo]

Nichicon KL low leakage is one of the best sounding electro couplers in current production, better than Elna, imo. BG are good too.

For PS the important thing is reliability. Nichicon Panny, etc. have good reliability. Use the mouser part selector to set your size constraints.

[jules]

Thanks Richidoo. It looks as though something is possible in Nichicon UFW or UKW, rated for audio use and quite small at 20mm diameter. KL low leakage? I'll see if I can "refine" my sear

[ainami]

For what it's worth, I have done a huge amount of testing with different types of electrolytic capacitors.  I have come to use Nichicon KW for any large size capacitor (like 3300uf or higher).  This is generally the best you can do in this size (unless you try to put in something like a Mundorf).

For any smaller capacitors, I have found that Nichicon Muse is actually the very best in sound quality and resolution.  They are very fast and clear, but they are very neutral as well.  If a Nichicon Muse is too big in a location, then Nichicon KW is a good substitute.

Nichicon Gold felt very bright and thin to me.  Maybe I just had the wrong combination or bad experience, but I don't like this cap.

Elna Silmic makes for an excellent DC blocking capacitor.  There is nothing better.  However, if you put this in the power supply section (as a filter or decoupling cap), then you lose quickness in the mids/highs.  It makes it more like a tube amp somewhat.  I think it's actually slowing down the slew rate of the circuits somewhat (best way I can explain it).  If you're after this type of sound, then go ahead and use them, but it's not my preference.  These do have excellent bass, however.

Elma Cerafine are better/faster than Silmic for a power supply cap, but they still are somewhat dark and don't have the quickness in the mids/highs.  Almost like overloaded bass.

All other caps are just not as good.  Keep away from the 105 degree (or higher) caps.  The internal material is chosen to operate in high heat and doesn't really work towards restricting electrical resonance.  Therefore, the 105 degree caps will have a tendency to sound worse.  Keep your choices to 85 degree caps.

If you have a multi-meter, check the voltages that are applied to these capacitors.  It is entirely possible that you don't need a true 63V cap.  Though, it's always good to pad the voltage.  For example, if the cap is seeing 30 volts, then it's fine to use a 35V cap (you don't really need a 50V).  The higher voltage caps are sometimes used because that's what is cheaply available from the board manufacturers.  The Nichicon Muse are only available in 25/50/100 (with limited caps at 100V).  I wouldn't go to the 100V unless the voltage on the cap was so close to 50volt that it would cause concern.  If the cap was seeing 48V, I might put in 100V just to be safe.  The only possibility that a 63V cap might be required is if the power supply is for tubes and has a transformer that is bumping up the voltage.

For your main 10,000 uf power supply cap, if you have the space to bump this up higher, it is always good.  If you have the space to put in a 12,000uf or 15,000uf, it will be better for bass and overall response.

[jules]

Thanks for sharing your research ainami ...

Expanding a bit on the reason for my initial question ... I'm building an active tri-amped system and while I'm happy with the amps for low and high, I'm a little doubtful about the mid-range which relies heavily on Nover caps. Nover are very cheap and are usually described as English though I believe they're actually Chinese [which can  be ok except that there's a deception going on].  I first had doubts about them when I looked inside a cap that had been damaged in transit ... very large cap with next to nothing inside  . From what I can pick up by extensive googling, they don't measure well and aren't worthy of good audio equipment. I'm not confident that their ratings for capacity, temperature or voltage are accurate so yes, some measurement is needed to determine the correct replacements.

So, I'm intending to replace some 10,000uF PS caps, some 3,300uF PS caps and various smaller [220uF, 100Uf and down] ones. Different caps for different jobs as you've said ainami, so thanks again for your suggestions. I think I can fit some Nichicon KW in the main PS positions and your thoughts on the Muse are most valuable. I'll probably use something like Relcap RTX for coupling as I've found them satisfactory in the past.

[wushuliu]

I agree with ainami on all points.

[jules]

Thanks Wushuliu. Given how much opinions usually vary on matters like this, complete agreement makes a very strong case.

[ainami]

I mentioned Elna Silmic as the very best -electrolytic- capacitor to use for a DC blocking signal coupling cap.  This is for those scenarios where it is not practical to use a HUGE MKP/film/polysteryne cap or if the circuit wants a really large value (anywhere from 10uf to 47uf).  If you have the room to put in a Multicap RTX or something similar, it is probably going to sound better than Elna Silmic anyways.  I cannot comment because I haven't tested these types of scenarios.  There are tons of choices for coupling caps and I'm sure they all sound different.  Though, I will say that film-on-foil (such as Kemet PFR) or silver-mica make the absolute best caps for op amp negative feedback sections.

[jules]

ainami you've actually answered some questions I didn't ask and that's very relevant to various challenges I'm scratching my head over at the moment ... thanks again.

Jules