2. tech-talk
  3. 1176609128

added amp...now hiss from spkr's

Addd an amp to the mix. SS multi-ch. Had no problems prior in relatively simple rig or atleast I did not notice. After making connections to recv'r(now used as pre/pro) I noticed a slight hiss/static like sound comimg from mids on my spkr's. So the process of elimination/isolation began. Long story short, I narrowed it down to the hiss/buzz coming from spkr's with only the amp connected. Nothing else...no interconnects no nothing. That cancels out cable problems, bad dvd player, etc, etc. Just power cable plugged in and wires going from amp to spkrs. When powered on it makes the noise. Amp runs quiet as far as I can tell when putting ear next to it. What's the deal? Tried diff outlets, diff spkr...makes no difference. When taking amp out of the mix and connecting spkr's to recvr, there is no noise at idle. Amp plays fine/sounds fine but the noise, although slight, is bugging me to pieces. Amp was shipped to me and had shifted cady/catty corner while in it's factory packaging which is pretty substantial. Perhaps it took a hit/drop...weighs about 80 lbs! Could something have gotten jared loose...a transformer which it has two of and quite large. Or is it the nature of the beast to output some noise when at idle? Thank you.
mnnc

Showing 3 responses by tiffany

tiffany
8 posts
 
I have the same hum problem with my amps... audible from the amps and through the speakers. Cheater plugs don't help. Has anyone tried PS Audio UPC 200 Humbuster?? Does this thing really work?
tiffany
8 posts
 
Mnnc, it's tempting to buy the PS Audio Humbuster and give it a try (I missed one on sale here for $150!) ....or simply send the amps back to the manufacturer for new transformers. But if it's truly "the nature of the beast" as many believe, then I would be wasting my money either way. Other people in the room don't notice the hum, but I KNOW it's there and like you, that bugs the heck out of me...because I've spent too much money to have something that hums & hiss as if it's defective.

Another advice I heard on minimizing the hum is to make sure the power cords don't touch any of the interconnects...or buy better shielded cables.

Hopeless!
tiffany
8 posts
 
I think most homes do have 15 amps and it's a good idea for you to upgrade yours...but I don't think that's why you're having the hum issue. I have a mixer/amp that hums loud and I managed to minimize that dramatically by just using the "cheater" plug. My Cary Rocket 88R is dead quiet despite cables overlapping and touching everywhere! My Cary V12i's mono blocs are the ones that hum and with my set up, it's impossible to keep the cables separated. I would have to sell all my cables and buy new lengths to accomplish that.

I will try to get my hands on a humbuster and let you know if it really works. In the meantime, we may have to just take many others' advice that it's "the nature of the beast" and overlook it as long as you don't hear the hum from your chair. With having said that, the room is soooo much quieter once I shut off the amps :( :( :( However, the music is still sublime :)

And if you haven't done so, try the cheater plug on your amp.
More to discover