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Capacitors in old tube amps?
I hope some of you electronics guru's can help me out. I got a vintage 60's stereo amp from Ebay a month or so ago. It's a little Japanese made Calrad SA-30B with 4 push-pull 6BM8 tubes giving it about 15 wpc. I am having a blast with this project. Waiting for the schematics to come this week, but meanwhile I tested it and one channel is weak and scratchy, the other one is nice and loud, but distorted, so I plan on replacing all the caps. Rat shack doesn't have beans for passive components, but they at least have resistors. There's a bunch of .005 uF paper oil caps in the chassis with TV1200 or 1200TV printed on them, along with the value. Can I use the Sprague Orange drops (polypropylene) as replacement caps. I can get the .0047 or .0056 in either 400V or 600V flavors. The same question applies to the ceramic discs, some of which look mighty ill, with suspicious bulges and corroded leads into the components.
Link for custom-built caps
Here's a link to a source for custom-built electrolytic caps that I have personally used a couple of times.
Zack Engineering is the name but here's the web site: http://www.vibroworld.com/. Ask for Zack.
What you'll need to provide are the values and voltage ratings you're looking for as well as the type of can you want to replace. Its a good idea to also provide the height of the can from the deck of the amp to the top point. Otherwise, you may get a can that's too tall to reinstall the cover. Ran into this with my 2 MX-110s. He got it all to work. Normal price for a 4-section can was about $25 ea. Not bad when you're facing the prospect of having to rejigger the underside to try to get discrete parts in there - not an option with the MX-110s.
I have seen some guys hollow out the old cans then stuff new caps in them but I broke off the tabs trying to get them out so that wasn't really an option either.
Hope that helps.
Cheers,
David