Wurlitzer piano 104B .39uf/200v caps

[punkykatt]

[punkykatt]

Hey Guys , working on this old piano. Im having a hard time locating a couple of .39uf/200v caps. Can I get away with using  .47uf/600v I have on hand?  The original caps say +_ 20% which comes out to .468uf.  In the previous post is the schematic.  The caps 59 , 60  are located  just after the small secondary  winding.  Thanks in advance. Punky

[sluckey]

Can I get away with using  .47uf/600v I have on hand?

I would. Why do you suspect them?

[punkykatt]

Thanks Steve.  The keyboard electrostatic pickups were not producing sound. I connected my guitar to the amp input, the amp and tremolo work OK.  Checking the circuit starting at the input jack, the 10meg is good,  up stream of the 10meg should be 180v, I was getting 0v.  Voltage stops at  jct of 22meg, 2.2meg and (59) .39uf cap. disconnected  all those caps and resistors and found one of the ,39uf`s not reading anything on my cap meter.  I want to rebuild that circuit.

[sluckey]

,39uf`s not reading anything on my cap meter.

Does it check shorted (or low resistance) with your ohm meter? How much AC voltage on the right side of the diode? How much DC voltage on the left side of the diode?

[punkykatt]

Dead short on the ohm meter on one cap, the cap i got no uf reading, AC voltage before diode is 153vac  after diode and 22k is 185dcv.

[sluckey]

Your .47s should get it up and running. Those caps function just like the electrolytic filter caps in your tube amp power supplies. Actual value is not critical.

[punkykatt]

Thank you very much for that very useful info.

[eleventeen]

If you have to buy any qty of them....realize you are using up 600 volt caps which are getting expensive these days. Don't know if you have any particular use for .47 ufd.....those seem to be used less these days than they once were.


But if you have to buy a load of new caps and wanted to feel right on the ufd value, you'd buy .22 ufds and place 2 in parallel.

[super&plexi]

I've got both .33 + . 39 at  least four hundred volts, probably more like 600 + 1000 I'd be more than happy to send you out two if you haven't got on with it already I think axial polypropylene ( tubular type) , and the other Style( are they called radial if they're not electrolytic) my memory escapes me right now and I'm too lazy to look it up

[super&plexi]

Oops I just saw your date of posting, I think I mistook 26 for the 16th you probably got on with it by now