Speaker buzz with SS amplifier, input disconnected

Thanks Attmasphere/RK
I've tried a couple of interconnects without change. I believe you are right about an internal layout problem. Both monoblocks buzz through the loudspeakers, one louder than the other, inputs either connected or not.
Would you kindly expound on the type of layout problem which might result in this speaker buzz. Can a noisy toroid transmit buzz to loudspeakers etc
I know most talk of noisy transformers in the chassis without transmission to loudspeakers.
Many thanks for your response!

Like Arh is asking above, is this a really bad hum/noise or is this just the tiny hum you might get from a floating input?

When 60 Hz hum becomes really bad, it can create a buzzing hum. The 60 Hz wave is so strong that it clips off at the peaks and creates many new frequencies that are higher order harmonics of 60 (120, 240, 480, 960 Hz, etc.).

If this is a pretty loud hum, then it sounds like you have either had a big electrolytic cap in the power supply going bad, or there is a short in the amp that is so bad it is bleeding the power supply down. If it is an internal short, then it will smell bad and be overheating. If it is just an electrolytic filter cap, it might slightly smell acidic, but won't be overheating that bad.

Anyway, sounds like she needs an overhaul.

Hi Brian- I had a similar issue with BAT monos a while ago. I would get a hum with the speakers connected and no input connected to the amp. Your amps were designed to run with XLR input and the amp will hum if there is no device plugged into the XLR inputs, so hopefully you have a preamp that has XLR outputs. IN the manual of your amplifiers, it states "In case you have a preamplifier with only RCA outputs, you can use the RCA input. Remember to plug in the XLR Terminator plug, when you use the RCA input. It connects the negative input to ground, making sure that the input is not “floating” with the risk of noise or oscilliation comming in to the amplifier circuits." So - connect the inputs of the amps with an XLR cable to the outputs of a balanced preamp and the noise should disappear OR use the RCA inputs to connect to the preamp and use the XLR Terminator plug as described and the noise should also disappear. I hope this helps.

The buzz is constant with balanced inputs connected or disconnected. I am using balanced cables between my VAC preamp and the Gamuts.
Thanks!......still buzzes, both channels but more on one side.

Did these amps have this problem from day one, or is this recent?

Do you have any other equipment near the amps that is on?

Do you have florescent lighting or light dimmers?

If you swap the physical position of the left and right amps, does the greater hum stay with the amp?

If you move one of the amps and speaker to another room, is the problem still there?

I'm trying to figure out if you might have electromagnetic pickup (radiated pickup). You can tell if it is radiated because when you move the amp around, the pickup will be greater or less.

Dimmers and florescent lights transmit higher frequencies that sound like buzz.

Power conditioning doesn't get rid of radiated pickup.

Possibly both amps are having electrolytic cap breakdown, but that normally happens one at a time on older amps.