dumb neeb cap voltage question (eh polyphase)

Started by pinkjimiphoton, December 23, 2012, 10:24:02 PM

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pinkjimiphoton

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.
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PRR

16V caps in a regulated 15V application may last long enough for him to score more bread. Months, years, decades.
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Mark Hammer

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.

pinkjimiphoton

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!
  • SUPPORTER
"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr