Fixing a Dayton SA1000's hum.

[eljay]

I posted this over on AVS as well, but I figure there's a better chance that someone here will have done this already... :)

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A couple of weeks ago, I picked up a used Dayton SA1000. It was extremely quiet (no humming, buzzing or any other sounds) when I got it, and for the first week it remained that way. Then it started humming quite noticeably (and the hum is amplified through the driver).

By comparison, the other SA1000 I have is still extremely quiet.

Having run a bunch of the usual tests on it to rule out other problems (like ground loop), I'm certain it's a problem with the amp itself. I read somewhere - regarding a different amp - that defective or worn "filter caps" may be to blame and that these usually can be replaced.

Has anyone ever replaced filter caps on an SA1000? If so:
- could you please indicate which parts you used as a replacement;
- whether a relative novice like me (with some, but not a lot, of soldering experience) could do the repair himself; and
- how well it worked out?

Thanks! :salute:

[boober]

You try asking sandbagger?

[Sandbagger]

You try asking sandbagger?

Me ?? :eek:

sounds like a ground loop but with nothing plugged in?

There are 4 caps next to the heat sinks on the input board. Take a look at the tops of the 4 caps and see if they are swollen?

I have had a total of 1 of these amps fail and it was either that caps went bad and took out the transistors or the transistors failed and took out the caps. my guess is bad caps.

I would put a name brand caps of the same voltage but you could go up one voltage level.

[eljay]

Thanks for the reply - much appreciated. :) I'll open up the amp when I get a moment and have a look at the caps.

[Sandbagger]

No guarantee that is the problem as these have been rock solid for me.

But the one that I did have that had a hum that is what I found.

Thanks for the reply - much appreciated. :) I'll open up the amp when I get a moment and have a look at the caps.

[eljay]

Fair enough. :)

[eljay]

I haven't opened up the "new" amp yet - I'm saving that for the weekend - but because it was on sale for $149 ($100 off) at FutureShop I thought I'd take a risk-free chance on a Monster PowerCenter HTS1600, just to see what would happen.

And what happened is that the hum was attenuated quite a bit. Not eliminated, but significantly quieter. That said, my "old" amp - which was plugged directly into an outlet, and not into the HTS1600 - was still dead quiet. (Which is how the "new" amp was for the first week I had it.)

So...what does this mean? Is a ground loop still ruled out, or does this rule it back in? Or does it just mean that the HTS1600 somehow massages the S:N ratio to an acceptable level, but that a bum capacitor might still be the most likely culprit?

Thoughts/comments are appreciated. Thanks! :)

[Sandbagger]

does it hummmmmm without a signal rca cable hooked up?

[eljay]

It hums with nothing hooked up to it and regardless of which outlet in the house I plug it into.