Replacement Sprague capacitor

December 18, 2010 8:30 AM

I have an old Stromberg-Carlson tube amp and I'm looking to replace the large Sprague multi-section capacitor. Of course, it's old and searches for something similar haven't paid off.

This is a four-section, marked as follows:

SPRAGUE

P-35590
40MFD/450VDC
30MFD/350VDC
15MFD/300VDC
50MFD/500VDC
CAN-NEG
D6488 96

It's a little over 3" high and 1.25" in diameter.

Does anyone know of NOS Sprague caps or someone who stocks modern replacements? I'd rather not have to replace this with four separate caps, but that's of course an option.

posted by tommasz to technology (4 answers total)

Have you tried diyAudio.com? There is a forum dedicated to tube amps there.
posted by Giggilituffin at 9:09 AM on December 18, 2010

In audio applications, usually those are Sprague Atoms. You can find them on eBay, among other places. You may never find that exact model number because it was probably made specially for S-C, but you can find an equivalent no problem. Here's another supplier.
posted by fake at 9:38 AM on December 18, 2010

You're probably going to want to do separate caps, though if you want you can chop open the old can cap and restuff it with the new ones. Finding a can cap with those specific values will be both difficult and more expensive than using separate caps.
posted by Slinga at 10:00 AM on December 18, 2010

Here is a page of good info on replacing old electrolytic caps. Note the section on "re-forming" which might bring your caps back to life for a few more years of use. There's also a section on rebuilding a can type cap, in which you remove the old caps from the can and place new (axial-lead) caps inside.
posted by exphysicist345 at 12:08 AM on December 19, 2010