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Coupling cap replacement in series?

Hey guys I'm trouble shooting a guitar amp conversion.

I want to replace the .047 600V coupling cap(s) that go into my 12AU7 phaze inverter.

I have 3 .2 caps I can series wire to give me the required 600V rating. It works out to a .06 600V cap.

Do you see anything wrong with that?

The leaky cap is on the left, the new ones on the right.

I have a thread in the musical instruments section.

http://www.diyaudio.com/forums/musical-instruments/175545-als-tube-amp-thread.html
 

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.047 600V caps are dirt cheap, but......

I think you would be closer with 4 in series, yielding .05uf and 800V with proper dropping R's across each cap.

You'll need to put balancing resistors across each cap so that they will equally share the voltage. 220K or so is typical.

You need the resistors because the resistance of each cap can vary, and they will not share the voltage evenly.....one can easily exceed it's 200V rating without the R's.
 
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I think you would be closer with 4 in series, yielding .05uf and 800V with proper dropping R's across each cap.

You'll need to put balancing resistors across each cap so that they will equally share the voltage. 220K or so is typical.

You need the resistors because the resistance of each cap can vary, and they will not share the voltage evenly.....one can easily exceed it's 200V rating without the R's.

That's a really bad idea for coupling capacitors. Those 220K resistors in series will make a DC voltage divider with the following stage grid DC return resistor, and that will throw off the bias. He'd be better off sticking with the leaky coupling capacitor.

It would be better still to try to obtain a coupling capacitor with the 600V rating. AuriCaps come in 0.47uF / 600V (or very close to it).
 
Ok sounds good.

I did try it real quick, it did "work" and cleaned up the sound a little.

I do have some other older caps that may be working.

Just playing around to see what I need. Making a list for new caps, but as this is a conversion project I got to fiqure out all my changes first.

Thanks guys.