These caps any good for amps?
Moderators: colossal, zaphod_phil, CurtissRobin, Daviedawg, Graydon
-
Psalm150
- Occasional poster

- Posts: 275
- Joined: Sat 03/15/03 2:00 am
- Location: Escaped from Porterville
These caps any good for amps?
I know they sound great in guitars, but anyone used these in amps?
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 3816559639
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 3816559639
0 x
-
Ethan
- Black Light Poster
- Posts: 406
- Joined: Wed 10/01/03 2:00 am
- Location: Brooklyn,NY
They can definitely do damage! When used as coupling caps, DC will leak through and can affect the bias of the next stage. It can red-plate your power tubes faster than you can say "Ooops...".
You could always test for leakage bfore using them, but I've found it's best to shy away from used and NOS capacitors. The Black Beauties almost always leak. It's true that old caps look very cool and have a certain sound, but there are enough choices on the current market to enable us to find good-sounding, reliable, modern caps for our amps and not worry about when the next cap is going to fail.
Peace-
Ethan
You could always test for leakage bfore using them, but I've found it's best to shy away from used and NOS capacitors. The Black Beauties almost always leak. It's true that old caps look very cool and have a certain sound, but there are enough choices on the current market to enable us to find good-sounding, reliable, modern caps for our amps and not worry about when the next cap is going to fail.
Peace-
Ethan
0 x
- s2
- Senior Amp Tech

- Posts: 3182
- Joined: Thu 05/20/04 2:00 am
- Location: Dallas, TX
- Contact:
-
Ethan
- Black Light Poster
- Posts: 406
- Joined: Wed 10/01/03 2:00 am
- Location: Brooklyn,NY
That's quite true of ceramic caps. I'd have to respectfully disagree about foil caps. many old foil caps use oiled paper as a dialectric and these caps can and do go bad. In some cases, really bad.
Several years ago I got some "Black Beauty" type caps from the late 50s which were the same type used in old McIntosh amplifiers. I later found out that all but one of those foil caps leaked, and roasted a pair of EL84s in the process. I have, however, used 50 year old ceramics that did not leak one bit. Very stable.
New, current production caps are definitely the way to go.
Now, Who's this making mustard cap repros?
Ethan
Several years ago I got some "Black Beauty" type caps from the late 50s which were the same type used in old McIntosh amplifiers. I later found out that all but one of those foil caps leaked, and roasted a pair of EL84s in the process. I have, however, used 50 year old ceramics that did not leak one bit. Very stable.
New, current production caps are definitely the way to go.
Now, Who's this making mustard cap repros?
Ethan
0 x
- zenin
- Newbie

- Posts: 37
- Joined: Thu 07/17/03 2:00 am
- Location: USA
- s2
- Senior Amp Tech

- Posts: 3182
- Joined: Thu 05/20/04 2:00 am
- Location: Dallas, TX
- Contact:

