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I have a weird buzz issue; can you help me solve the problem?

Hi - my integrated amp has a 25db persistent buzzing noise; I need help figuring out how to solve this problem.

Here’s my system:
CODA CSiB integrated amp - custom tuned to produce 25w Class A power before switching to Class B
Lumin T2 streamer/DAC
Dynaudio Focus 380 speakers
Audience AR2-T2 power conditioner w/Audience power cable
Audience AU24 speaker cable
Cardas Clear M power cable
Purist Venustas Luminist Revision RCA interconnect
Synergistic Research TeslaPlex SE outlet
Shunyata Venom Defender

Some background:
I’ve had the CODA integrated for about 5 years. The remainder of my system has come on-line subsequently (I had different speakers initially). Within a few months of purchase, I noticed a buzzing noise coming from the speakers whenever the amp was powered on (bias “on”), but no noise in standby mode (bias off). I took it back to the manufacturer, who plugged the amp into their dedicated circuit and it was dead quiet. I had the same experience taking it to a local audio shop. Thinking that it might be a noisy circuit, the local shop loaned me a lesser priced solid-state amp (I forget which brand) to bring home. I hooked up the shop’s integrated to my system and.....it was dead quiet. Now I was confused. 

A dealer loaned me a completely different system with a tubed integrated, different speakers and cables. There was even a worse buzz coming from this system than from mine. I went back to living with my system and forgetting about the buzz.

Fast forward 4+ years. I have moved to a new house in a new state. Unfortunately, the buzz remains :-( I even tried plugging the system into what the electrician was sure was one dedicated line in the house (it was in the kitchen, so I had to run an extension cord to where my audio system lived). Still, the buzz remains.

I really love the sound of my system, but this persistent buzz is a (ahem) buzz kill (sorry for the predictable and bad pun). 

I would love to get some thoughts on what I can do to get rid of this damn noise. Please help!



mwsl

Showing 2 responses by cakyol

cakyol's avatar
cakyol
940 posts
 
You have a ground loop. Get rid of the power conditioner. Plug ALL your devices to the SAME outlet (star configuration). Basically the grounds of all your devices must be at exactly the same potential. Any resistance between different grounds will cause hum or buzz. It is impossible to get it to zero resistance but minimizing it is the goal.  Get rid of all esoteric plugs and power conditioners. You dont need them unless you live somewhere with a lot of lightning strikes. 
If that does not work you should make sure all your signal cables are shielded (like coax cables) and are not close to higher current cables like the mains and speaker cables. 
cakyol's avatar
cakyol
940 posts
 
The next step would then be to make sure that all the signal cables you have are shielded like a coax cable. I had a problem like that once and it got fixed when i changed the signal cable. I presume your cables are good but just be sure. 
You can also try moving JUST the amp to another mains plug in another room, put headphones on and WITHOUT anything connected to its inputs see if you also get the buzz. I have a feeling your streamer and amp are having a ground loop issue.
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