hey guys, probably a dumb question, but here goes:
i have an old EH polyphase on my bench, working on it for a friend who doesn't have a lot of money.
a musician...yep.
anyways, i fixed a whole bag of crap for him tonite. some was operator error..
a dano cool cat chorus won't light up at 9v no matter what ya do..
and some was mechanical failure...a nice maestro bass brassmaster with a bum footswitch.
the poly phase had a couple issues...one of the coupling caps had pulled free from the pcb (factory f-up) and a wire had come loose from the envelope/sweep switch.
i have achieved sweep, i have achieved envelope, but it's fairly garbled and distorted sounding as it passes signal, and the effect is extremely weak.
i haven't bothered to write down voltages yet, cuz i'm figuring a nearly 30 year old pedal, the electros are cheese...so i wanna replace 'em all first.
so here's my dillema..it doesn't have all that many electros to deal with, which is good. i have most of 'em in stock here. but a couple i only have in a 16v rating.
now i know a cap should be able to withstand a "surge" voltage of about 1/2 it's rating. this thing's transformer is pumping about 20 volts, and i'm getting 15v from the output of the regulator. so i'm assuming that parts ok.
here's the question..can i get away with using 16v rated caps in there, or should i hit him up for bread to get 35v ones? they're rated just a little higher than the B+ supply... do you think it will be alright to use them in this application?
thanks for the advice. i really need to get this off my bench so i can get on to some paying jobs i've been neglecting.
16V caps in a regulated 15V application may last long enough for him to score more bread. Months, years, decades.
A lot of the electros in the Polyphase are simply pasing audio, in which case the AC signal level will only be maybe a volt or so at most....well under the 16v rating. Personall y, I wouldn't stick a 16v rated cap on the power supply, but for the audio path, you're good to go.
sweet...thanks paul and mark.
the power supply caps i'm good to go with 50/100v caps. it's just some of the caps in the audio path i was worried bout.
good to go now..thanks you guys!