Speaker buzz with SS amplifier, input disconnected


If a buzz/hum is present from my loudspeakers with solid state Monoblock inputs disconnected, what are the likely possibilities accounting for the buzz. Do toroidal transformers ever transmit transformer noise to the loudspeakers?
I thought ground loops were more or less eliminated with amplifier inputs disconnected. Buzz/hum is present in both loudspeakers(with inputs disconnected), more pronounced in one. Thank you for your suggestions!

Amplifier. Gamut M250
Speaker. KEF Blade
audiobrian

Showing 1 response by jwpstayman

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.