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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
mnnc OP
175 posts
 
Hens, Sometimes, perhaps one out of every ten 'power ons' the amp will emit a little vibration/rattle but then settles down to dead or near dead silent operation. I don't have any abnormal quirks like sound cutting out, volume change, run hot, harsh distortion, it operates fine imo. However, I don't have it on a test bench w/ test equip and would not know what to do if I was in such a sutuation. Question, amp and recv'r both have pwr cords that are 2 prong male/2 hole female. The cords are removable type but only 2 terminals vs 3 ? Perhaps a gnd issue? I assume the manufacturer designed it knowingly. Amp list 2k and recvr list 3k new. Although I did not pay that much. Should I forget about it and just crank it/enjoy!?
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?
mariasplunge
174 posts
 
I've got it too through my ss mono blochs. Haven't tried to do much in terms of fleshing it out. I just considered it the nature of electronics. Mine is only audible with my ear right at the tweeter but does increase/decrease with volume control.

What do ya know.
mnnc OP
175 posts
 
Tiffany...I have read according to ps audio's website that the unit will indeed eliminate all if not most of internal transformer hum. In fact, I visited the site to do some research and according to them, if I remember correctly, an amp that hums w/o any thing connected is perhaps in need of repair. But owners here say it's the nature of the beast!!!!???? I should be grateful it powers up and works. But that hiss, buzz, slight hum is still bugging me. I don't see how an electronic device that received superb reviews and price lists in the thousands can be broke if it makes a little bit of noise. But then again...?
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!
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