noise/hum

[indcrimdefense]

i have a low level noise/hum coming from my front speakers, which currently are the only speakers hooked up. with no music on, and turning up the volume, the noise increases. using a monster hts 1000, have tried plugging into different outlets, both switched & unswitched, both 15 & 20 amp. the noise is less using the hts 1000 than without. have made sure that all power cables are seperated from all speaker cables and interconnects. noise level is the same regardless of whether the cable is hooked into the system or not (and when i unhooked the cable, unhooked all of it, from the wall, unplugged cable box, etc.) current components are anthem avm 20 processor & krell kav-2250 amp, rf-7 speakers. generally noise is not noticeable when playing music except for quiet passages. to a greater or lesser extent, i have always had this noise problem, and i want to get rid of it. noise problems primarily exist when i add an amplifier to the system, and level of noise depended on the particular amplifier. the cary audio cinema 5 was by far the worst, and that was the single reason i did not buy what otherwise was a spectacular multichannel amp. however have had some noise problems with any of the amplifiers i have used, with the exception of the krell showcase 5, which was dead quiet when used w/ my denon 2805 as a pre-pro.

i reviewed the krell manual, and it recommended connecting the amplifier directly to the ac outlet, which i have now done. rest of system is plugged into hts 1000 powerstrip. while there is still a slight noise coming from the speakers when no music is on, the noise heard while music is playing is somewhat reduced. also seems to be an improvement in music quality. i'm quite uncomfortable having an amp hooked up without surge protection. the manual states to contact krell or a dealer before "using any devices to alter or stabilize the AC power..."

current outlet being used is 20 amp gfci in the kitchen & only other thing plugged in is the hts 1000 for the other compoents. (power cord goes from living room to kitchen through decorative opening in the wall). i have checked the breaker box & this is only plug on this particular breaker. eventually going to have dedicated 20 amp circuits installed, one for amp and one for components.

any suggestions on further eliminating noise from my system.

 

[tbewick]

Your problem sounds quite odd. Have you tried using another pair of speakers to see if the noise is still there? You could try swapping other components around to see if that makes a difference. Most decent quality pre/power amps have a signal to noise ratio of around 100 dB, so there shouldn't be any background noise on a digital input (e.g. DVD, PCM CD audio).

You could even try setting up your system on a different circuit in your house or even at someone elses house to see if the problem persists.

 

[indcrimdefense]

have switched around speakers (RF-7 fronts & RF-5 rears), and last time i tried there was less noise using the rf-5 speakers. however the speakers do have different specifications as listed at klipsch.com. i don't think it's the speakers as i don't have the problem when i was using my denon 2805 without an amplifier. have tried on every outlet in 3 different rooms with no difference between rooms. it's not a loud noise, but it is noticeable. have heard several of the amps in the store & didn't notice any noise problems that i recall.

the only power conditioners that i know are available in indianapolis are monster & panamax. monster has received enough of my money, really don't want to give them anymore unless i know it would solve the problem. have heard good things about richard grey's power company, but fairly expensive. however, if a good power conditioner would solve the problem, then im willing to spend the money.