Nikko Alpha II Capacitor question

You should find that 2 of them are shorted on the PCB, so just use either.

New caps are going to be a lot smaller so won't need the same physical mounting.

Also, check the temp rating of your replacements. Make sure you get same or higher temp rating. More temp = longer life.

the three pin types are still available, check digikey, do some searching.

if they are three ’wire’ types as the cans have solderable tabs for wire, or if they have tabs or pins that are for sticking through holes for soldering right to the board...both types are generally available.

You might have to go up in voltage and capacitance, to like 80vdc at 12,000 to get a can that is the same size diameter.

If they look like this (except three pin, not 4), then you should have the ability to get a higher voltage replacement. A higher voltage is fine, no big deal. (Image is of nikko alpha 440 capacitors)

They are still made in that pin configuration, finding them in stock is the bigger problem.

try digikey, mouser, newark, and so on.

Have you taken them off the PCB? I don't think you will find any 3 pin capacitors any more anywhere near that size, only 4 pin.

They aren’t actually soldered to the board. They terminals are connected to wires that form a bit of a pigtail around them- the pigtail grips them. The capacitors are roughly 1.5” in diameter and 3” tall. I will look at digikey.  Thank you all for responses. 

In addition to temperature rating, look at the hour rating. You may find 5000 hour/105C, and say 8000 hour, 85C. The 5000 hour unit will last much longer as life doubles for every 10C drop in temperature from the rating. So at 85C, that 5000 hour capacitor is 20000 hours.

Also look at the ripple current rating. Higher is better. However, you have to look at the ripple current rating at 120Hz (or 100Hz) to match your line frequency.

If you have any questions, post links to the caps on Digikey and we can help you with them.

https://www.mouser.com/Passive-Components/Capacitors/Aluminum-Electrolytic-Capacitors/_/N-75hqt?P=1z...Here are options from Mouser. I was initially wrong- the current capacitors have only 2 terminals- but each terminal has 2 poles to attach multiple wires. 40x80 seems to be a size that would fit nicely.  Any suggestions? Here are the current capacitors. The large black ones.

Hey sorry I just saw this.

If I was designing a power supply/amplifier from scratch, I would pick the UCC capacitors (make sure right terminal type)  --- lower ESR, lower dissipation factor, higher temp, longer life, higher ripple current rating, same price as the Nichicon audio capacitors .... all those features you want in a good power supply capacitor. It will provide a more stable power supply, longer lasting power supply if that is your goal.


Lower ESR on the other hand means larger current spikes when the capacitor is charging at the peaks of the AC waveform and I don't know how the designer dealt with these and the EMI they create (if they did at all - it adds cost). It also means higher delivered current (at higher frequencies) to the output stage ...generally good, if the amplifier is designed for it.

The Nichicon audio capacitor you listed does to have a compatible PCB mount. Check closely in the spec. I don't think it will work. You can pick a different one that will though.

If you like the existing sound, which is coming from what appears to be degraded capacitors, then the electrically "softer" Nichicon are probably going to be more to you liking.  Me personally, I would put in the 22,000uF that are in the same size, ensure I have a slow blow high I2T fuse to prevent fuse damage (from inrush), and hope for the best (and then work through the consequences).