I have 4 Dynaco A-25 way back from the college days. We're going on 40 years here. I question where the original crossover caps have have decided to drift from 5uf and 50vac. It seems when people re-cap they keep the same uf, but often double the voltage. Sooooo, when I order bi-polar crossover caps is your advice to stay at 50v, move up to 63v, even 250v. The uf determines the crossover point; does the v act as some sort of fuse?

"There has never been a good war or a bad peace." Ben Franklin.



2013-05-10 4:11 pm
THe voltage differences have more to do with availability. Most film caps don't go lower than 100V. There is some belief, maybe even measurable lower ESR, that the higher voltage caps may sound better, but I have not found that to be the case.

No, the voltage does not act as a fuse, it's the opposite. Exceed the voltage and the cap shorts. So it's really more of a measure of maximum weight limit. Another way to think of it is maximum pressure that can be exerted against it before it rips.




2012-02-10 12:12 pm
Whatever you buy will be fine having in mind that this is probably
a 30W rated loudspeaker. You would probably fry the drivers many
times before you will do the same to a capacitor. Audiophiles are
known for their sanity at upgrading filter parts, so if you fall in the same
category, you won't get anything less than polypropylen caps, and these
start at 250Vdc and up. :tilt:


2013-05-10 4:11 pm

I stand corrected.

Lojzek is correct. 250V is the usual minimum voltage for decent film caps, but you can find Elna bi-polars ($1 for 4.7 uF/100V) and rarely some ultra high end film caps starting around 100 V.

Lower V values either aren't popular, or are just to difficult to manufacture for some of these technologies.

My mistake.