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previous: Jim S. The dark blue caps (poylester film ... -- 4/14/2000 7:33 PM

Re: mid-70's Pro Reverb cap question

4/14/2000 9:12 PM
Gustav	Re: mid-70's Pro Reverb cap question If you have a cap tester that can check the leakage at working voltage. If the leakage and value are ok I would not replace them. Does the amp make alot of PS noise, if so does it go away that noise is caps forming up sometimes that have not been used for over a year or more. I power up all my tube amps and solid state every 6 months to help keep the electros "in shape". Most of the older caps were bigger and had a ESR of under 3ohms (22uf)If you replace the caps find a good modern one with a ESR under 2 ohms for the plate and screen part of the PS circuit. FWIW I use polypros in the PS sections of tube amps if I can fit them. I "fit" polys in my laney VC30. I don't hear a difference between good electros and polys but polys dont age like elecros. R.G. has wrote about this using motor starter caps if I remember correctly.

4/14/2000 9:12 PM

Gustav

Re: mid-70's Pro Reverb cap question

If you have a cap tester that can check the leakage at working voltage. If the leakage and value are ok I would not replace them. Does the amp make alot of PS noise, if so does it go away that noise is caps forming up sometimes that have not been used for over a year or more. I power up all my tube amps and solid state every 6 months to help keep the electros "in shape". Most of the older caps were bigger and had a ESR of under 3ohms (22uf)If you replace the caps find a good modern one with a ESR under 2 ohms for the plate and screen part of the PS circuit.

FWIW I use polypros in the PS sections of tube amps if I can fit them. I "fit" polys in my laney VC30. I don't hear a difference between good electros and polys but polys dont age like elecros. R.G. has wrote about this using motor starter caps if I remember correctly.