Hum From Speaker

I got the powervar and still the Hum is there. Try a different outlet still Hum is there.

So I am convinced that the Ebay guy sold me an amp with a low hum. I searched the internet and found that in old amps the power supply caps can dry out and cause the hum I am getting.

My amp is ten years old.

So does it make sense if I ruled everything out except the Amp that the old Power Supply Caps of the Amp can cause the Amp to hum?

Ghstudio

Thanks for your reply.

Do not have a friend's house that I can test my amp, but the ebay person I brought the amp from said it was dead quite at his house.

If only the amp is plugged into the wall, how could it be a ground loop ground?

Also wouldn't using a cheater plug as a test rule out ground loops?

When I think about it; I have three refrigerators in my house, maybe they are causing main line pollution?

I just ordered the Powervar ABC-1200-11 and I hope it will help. If that doesn't work I may take the amp to a repair shop to be tested.

My Denon 1906 Receiver was dead quiet in the same location, does that mean anything or is the technology completely different for those products?

I dropped my Amp off to a local repair guy today and hummed at his place too. Wasn't easy to find one. He is charging me $50 per Cap (2) and $75 FOR labor.

He believes the two caps are causing the problem but if it isn't the caps, it could be the two bridge rectifiers. If the caps do not solve the problem, then we will try the rectifiers.

I will post the results of the repair job. I guess my point is not all humming is caused by ground loops or noisy electrical feed from the mains.

Once my Powervar ABC-1200-11 gets here I going see if that helps. If not I am going to try my dedicated 20 work space outlet with nothing else hooked to the outlet. Can't turn off the every circuit breaker because I share that with the apartment next door.

If I still have a problem I am going assume the Amp is the problem and call Sunfire for service. If Sunfire finds something wrong with the Amp, I think I should ask the Ebay guy to pay for the repair. What do you think?

Thanks for the help and I will keep you posted

Ghstudio

You were right about taking it to another place. I guess I was holding out hope the Ebay guy was telling me the truth.

Once I have the final charges, I will file a complaint with PayPal and Ebay.

Thanks for your help.

Ghstudio

I guess I can ask the seller to do the right thing and pay for the repair. If he doesn't then I settle for giving him the feedback he deserves.

Either way I will enjoy the amp. It sounds really great except for the hum. Thanks for all your help. I will post the results of the repair.

My repair guy just changed out the caps and it still hums. He found on one of the bridge rectifiers that it has large ripple on the positive side. He is going to try to change out the bridge rectifiers, but if that does not help he does not know what else to do.

Any opinions?

New Caps and Bridge Rectifiers did not help.

So I am sending to the Rita Helm Carver/Sunfire repair shop. For a flat fee of $175 plus shipping they will restore the unit to new condition with a one year warranty.

I will update the post when I get my amp back.

Just got a call from Rita's Vintage Audio and they told me they fixed the Hum problem and will be benching testing the amp for two days to make sure no other problems show up. Found 18 caps that needed to be replaced and will replace a relay for good measure. All this done for only $175.

I will update this thread once I get my amp back to let you know how the amp sounds to me.

After Rita's Vintage Audio replaced the Lytic caps on the Amp Channel Boards and the Tracking Downconverter Power Supply Board the hum is gone. Bob Carver signed my amp too.

The Amp sounds awesome. Thanks Bob and Rita.

Also thanks to Ghstudio!!!

Thanks Nasaman