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Ashly FET-500 Hum -- Help, please.

50.55.208.239

I have a FET-500 that hums. The amp itself hums when it is on, meaning you can hear it even when nothing is connected to it -- no speakers, no inputs. You can of course also hear hum in the speakers as well, even with no input. The hum is (at least mostly) AC line frequency. Is this likely a simple matter of replacing the power supply capacitors or might there be more to it? The caps are 15mf, 100V. ** edit: The Rubycons at Newark are pretty reasonable and are screw terminal...and there are some BG brand caps on ebay that would work.
If I replace the caps is there any reason I can't solder in caps with leaded or snap in terminals instead of using screw terminals? That would give me more options in terms of affordability. Would I realize a big difference in performance between brands? The ones in there now are Centralab.
I would like to use this amplifier to drive the bass in a bi-amp'ed 2-channel home hifi setting.
Thanks for any help / guidance here.
-Michael

Edits: 09/20/11

Follow Ups:

RE: Ashly FET-500 Hum -- Help, please. - Pro Sound Guy 07:22:49 09/20/11 (3)
The power supply caps would be the first to swap out yes...

Look into

Elna Silmic II Capacitors

Black Gates are history and the only ones out there is what is left and
getting older by the day.
- RE: Ashly FET-500 Hum -- Help, please. - Thorozine 12:15:13 09/20/11 (2)
  I don't think Elna makes anything nearly the size of what I need, Silmic or otherwise. These things are roughly the size of a soda can. 15000uf, 100V (maybe I should have stated the value in microfarads instead of millifarads in the first post).
  - RE: Ashly FET-500 Hum -- Help, please. - Pro Sound Guy 06:30:22 09/21/11 (1)
    Ok here
    - http://www.partsconnexion.com/capacitor_ele_nichicon_kg.html (Open in New Window)
    - RE: Ashly FET-500 Hum -- Help, please. - Dorcus_Maximus 09:25:16 09/21/11 (0)
      Nice. Thanks. A little more expensive than the Rubycons but I know the KG caps are well regarded.
      
      -MF (formerly known as Thorozine...)

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