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
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. 
I want to see if your speakers had two sets of binding post. If they did I wanted to isolate top from bottom. Red, or black disconnected..its gonna stop making the noise, has to.

If one speaker STOPPED the noise in the other, we would have been close..

A small set of different speakers is easy.. and different speaker cable, zip cord is perfect.. Swap them out.. if no change, and without a Variac, there is one other freebie.

Unplug everything in the house, everything.. Home security, electrical, especially 220. Everything that has a plug, UNPLUG it. From RJ11 to RJ45, phone land lines, network cables, cable boxes, unscrew, unhook, undo EVERYTHING. Turn off all battery powered led, if they have a monitor light, take out the batteries, turn off your cell phone, WiFi EVERYTHING in that house OFF, and unplugged, and power removed, batteries too.

Get a long extension cord.. Start plugging in all over the house, see if the noise changes or goes away.

If by chance it’s gone, leave it plugged in wherever it’s quiet, and start plugging in a room at a time. Then any 220 plugs, then the land lines, network cable.. Isolate then fix.. ok

Now you can turn your cell phone and pacemaker back on. If the noise starts then, you really got a problem..

If you can’t get a variac and drop the voltage... it’s Shop time.

I ran out of no cost test..

Hang in there, after all this time.. you’ll get it..

Regards
This is a great thread.  I have a buzzing problem but I know what's causing it.  Can someone explain in greater detail how to make it stop?

My 2.1 channel listening system is part of my 5.1 home theater.  There is a quiet buzz coming through my 2 main speakers which are powered from a Parasound amp.  All I have to do to make the buzzing stop is unplug the cable box HDMI cable from the TV.  This seems strange because the cable box is still connected to my receiver for audio.  The TV is still connected by HDMI to the Blu-Ray player and directly by HDMI to my Mac Mini music server.

So, jumper wires, shorting plugs, ground cheaters?  Can you explain in greater detail?  I believe all units are currently plugged into the same power conditioner (which I bought used for $100 on Craigslist many years ago).

For now I just leave the HDMI cable from the cable box unplugged because it's amazing how LITTLE regular television we watch any more.  Most of our viewing these days is Amazon Prime/Netflix streaming from the Blu-Ray player, or MasterClass watched through the Mac Mini web browser.
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