Before you waste hours and assuming you can lift that beast....take it to a friends house and see if it hums there. You either have a ground loop, something causing noise on the line, some transformer still plugged in near your amp causing interference...or you have an internal amp problem.
You've already eliminated the real easy things. Finding ground loops and noise sources can be very tedious....so first find out if your amp is OK. |
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? |
make sure you do all your testing within 60 days so you can file a claim against the seller if you find that what he claimed isn't true. Some EBAY sellers are known to stretch the truth or claim dumbness....although most are very honest.
If your denon was dead quiet, then the amp you bought is suspect. However, disconnect everything you can in your house or turn them off and see if any of it makes a difference. |
I would try moving your equipment to a different power outlet and see if you still hear the hum |
Some possible causes people forget about include light dimmers (especially halogen), lamps that you turn on by just touching them, lights that turn on automatically at dusk, small transformers plugged into the wall, florescent light fixtures or even "energy saver" light bulbs, pool pump, water heater.
Turn off every circuit breaker in your home except for the one that you have the amp plugged into...then make sure there is nothing plugged into any other outlet on that circuit...nothing. |
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 |
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? |
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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. |
which is why I suggested taking it somewhere else to see if it was internal....
The caps should solve the problem. Likely only one was leaking, but you might as well replace both because the problem is age related. |
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. |
unfortunately, paypal and ebay will only step in to get what you paid back....and then only if you send the original product back to the seller.
If you keep the product and expect ebay and paypal to help you get the repair costs...it won't happen.
So...just pay the money to fix it and enjoy it....but don't expect anyone to pay for the repairs. Welcome to EBAY.... |
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!!! |
Srlaser,
It was a very good following up, enjoy. |
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