Are 450VDC Solen Caps the wrong choice?


Im upgrading the caps in an old pair of Marantz Speakers. Each speaker uses (2) 10uf 50VDC and (1) 33uf 60VDC Culver caps. I bought Solen caps to replace them with ( same values, ie 10uf and 33uf), but noticed they are rated for 450VDC. Is this a good thing or bad. Cost is not an issue and even though the Solens are physically much larger its not an issue.Would I be better off with caps rated at 250 VDC? I want to go with the Solen. It seems all quality metallized polypropylene are either 250 or 450 VDC. Speakers are rated at 250 watts RMS max , amp puts out 125 wpc . THANKS for any help.
Jeff
jeff66
The high voltage rating implies that the dielectric between plates of the capacitor is thicker. I think that there is some grounds to suspect that the capacitor might sound different (maybe better). Certainly the cost was higher.
Caps typically work best when run up close to their nominal rated capacity. Having said that, these caps will work fine and probably better than what you had in there before.

One suggestion that i would make is to "form" the caps prior to installation. That is, find someone that can bring the caps up to or very near rated voltage for an extended period of time and then let them sit for a day or two. Discharge the caps in a safe manner than then install them into the circuit. Keep the leads as short as possible and use a heatsink ( alligator clip ) attached to the lead when soldering. Applying a small amount of "blu-tak" or something similar around the point where the lead enters into the body of the cap can also help reduce capacitor induced microphonic distortions.

All of this might be beyond the potential capacity of the Marantz speakers that you're working with though, so use and apply as you see fit. Either way, what you're doing should improve the performance of the speakers, but be prepared. They WILL sound markedly different, especially at first. I wouldn't expect them to sound "good" until you can get quite a few hours on them at pretty reasonable volume. After that point, the sound should clean up and be more focused, losing a lot of the bright edge that you'll initially hear. Most of the time, fresh solder connections & new caps in a speaker sound absolutely horrible to me, so don't be dismayed if you run into a similar situation. Sean
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PS... while you're in there, check out what they are using for internal speaker wire. I'll bet that you could make some forward leaps in that area too....