[Paxonator]

alright I just bought a MAD EAR+ HD and hooked it up. There's a very audible humm coming from it. The humm goes away if i disconnect the rca cables, but as soon as reconnect them to my 0404/laptop/dvd player it returns. The source could be plugged into the wall or not with the same result. I've also tried a different interconnect. The humm also gets louder as you turn it up. What can i do to remove this humm??? Thanks

 

[sacd lover]

Quote:

Originally Posted by Paxonator /img/forum/go_quote.gif alright I just bought a MAD EAR+ HD and hooked it up. There's a very audible humm coming from it. The humm goes away if i disconnect the rca cables, but as soon as reconnect them to my 0404/laptop/dvd player it returns. The source could be plugged into the wall or not with the same result. I've also tried a different interconnect. The humm also gets louder as you turn it up. What can i do to remove this humm??? Thanks

You almost assuredly have a ground loop. Try using a 3 to 2 plug adapter and lift the ground on your source.

 

[achristilaw]

Well it's the process of elimination. What else shares the circuit. Video products make the most noise. Old VCR's can be brutal. Do a lot of plugging/unplugging. Is it audible through the phones? Or is it the physical unit itself? Is it tube generated? Swap tubes of the same type to different sockets. Cordless phones with answering devices I've had trouble with also. Any electric motors sharing the same circuit?
You can "lift" grounds also as a last resort. Since you just received it call Dr. Lloyd and get his advice. Hope you get it sorted out.

 

[orkney]

The EAR should be pretty quiet. Many (IME) tube amps tend to have a bit of transformer hum but it shouldn't be audible at anything but high volumes. One thing to watch for is DC on the line, which can saturate a transformer core and produce significant hum. Fan heaters, hairdryers and so on -- anything drawing 750 watts in my house -- can be a culprit here. Products like the Humbuster can help but the only thing I've found that works perfectly is to find the offending appliance and unplug it. There's lots of great advice in this thread -- best solution is to take your time and eliminate possibles one by one...

best,

o

 

[Paxonator]

Alright I have tried different 12B4A tubes with the same result. Unlplugged everything from surge protectors except amp and computer. The humm still dissapears in it's respective side after disconnecting the left or right channel anywhere along the chain. The humm is coming from the headphones not the amp.

Update: I've also went around unplugging my fridge and tried a different 5751 tube as well. And as for removing the ground am I supposed to do this on the amp or the computer?

 

[orkney]

Quote:

Originally Posted by Paxonator /img/forum/go_quote.gif Update: I've also went around unplugging my fridge and tried a different 5751 tube as well. And as for removing the ground am I supposed to do this on the amp or the computer?

Amp. Try plugging it in via a cheater plug and double-check the interconnects to make sure that they're securely plugged in but that there is a tiny gap between IC collar and the amp-edge of the female RCA jack, if that makes sense.

o

 

[Paxonator]

Quote:

Originally Posted by orkney /img/forum/go_quote.gif Amp. Try plugging it in via a cheater plug and double-check the interconnects to make sure that they're securely plugged in but that there is a tiny gap between IC collar and the amp-edge of the female RCA jack, if that makes sense. o

GREAT it works! I just snapped that ground right off on a cheaper power cable i had kicking around. But now it's quite... ah yes silence... I'm not sure if that's a "proper" fix but it'll work for now. Thanks everyone for the help!

 

[achristilaw]

Quote:

Originally Posted by Paxonator /img/forum/go_quote.gif GREAT it works! I just snapped that ground right off on a cheaper power cable i had kicking around. But now it's quite... ah yes silence... I'm not sure if that's a "proper" fix but it'll work for now. Thanks everyone for the help!

HOOOORAYYY!!