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Topic: Using a Variac Powerstat 3PN116B To Reform Caps in an AMP |
Don Brown, Sr.
From:
New Jersey
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Posted 2 Jan 2009 11:26 am |
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Could someone tell me what would be a good recommended Voltage Setting to start out with, on an older Fender Twin Two 12's that's been supposedly recapped approximately seven years back, but has been sitting in storage for 5 years without being powered on?
And, what steps would you take. Tube amp with apparently solid state rectifiers, quad 6L6GC tubes.
Thanks,
Don |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 2 Jan 2009 6:38 pm
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Normally, about 30-40 volts, and then ramp them up in 20 volt increments. But personally, I really wouldn't worry about it if it's only been out of service for 5 years, and the caps are less than 10 years old. The tubes and all the other components aren't affected much by age, so I'd just turn it on, and give it a minute before I played through it.
Now, if the caps were original, and it was out of service for more than 10 years, that would be a different story. Also, if there was rust or oxidation on it (chassis and tube shields), I'd remove the tubes and re-insert them a few times to clean any oxidation off the pins before I fired it up. |
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Don Brown, Sr.
From:
New Jersey
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Posted 2 Jan 2009 7:06 pm
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Donny, Thanks a lot..
Wishing you and yours a, great New Year.
Don & Family |
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Marty Smith
From:
California
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Posted 4 Jan 2009 2:53 pm
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| what if its been 2 years but the caps are 50 years old. How long do they last ,generally? |
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Don Brown, Sr.
From:
New Jersey
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Posted 4 Jan 2009 5:51 pm
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Marty, if the caps (Electrolytic) were fifty years old, regardless. They'd have been replaced long before they got to be that old.
The hardest thing on them, is during times of not being used. That also pertains to brand new caps sitting on a shelf a few years as well. The only safe way is to reform them before using.
However, that calls for a whole different approach, using current limiting resistors, etc., along with metering as well so you can tell what's taking place as you're reforming them. A neon bulb placed in the circuit will also work ok, with a well designed reforming circuit in place, to allow you to see what's taking place.
Wishing everyone a Happy New Year.
Don |
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Marty Smith
From:
California
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Posted 4 Jan 2009 6:17 pm
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| I think Ill change em, the are the CD blue beaver 40/150 said to be made in the 30's! |
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