Hearing noise in a balanced system

[prasanthgnath]

Hello,

I have a Hypex based 6 channel set up: Digione--> Hypex DLCP --> 6 channel Hypex UCD amp --> Linkwitz Studio.

Yesterday I heard some sort of noise, a kind of hum, about 120 hz through the speakers. (Power supply voltage is 240)

This is a fully balanced kit. Wiring is as per Hypex recommendation, ie for each channel, shield cable from dlcp board goes to DLCP end XLR pin 1 --> Amp chassis XLR pin 1 --> Ucd amp board signal ground pin. XLR pin 1s are shorted to chassis at both sides.

I use Hypex interconnects between the DLCP board and the Hypex Amp chassis.

Technically, I shouldn't hear any noise or hum right? Where could theory be going wrong, then?

Advice welcome.

 

[Mark Tillotson]

Amp is producing hum? The amp isn't differential or balanced, only the interconnects.

 

[Speedskater]

remove the XLR interconnect cable, does the amp still hum?
if not, try some other music source component.