Humming/Buzzing sound from speakers

[avr]

Greetings All,
There may be a lot of threads on this issue, if yes kindly provide the link to my problem. I have an Onkyo 3010 AVR used as the preprocessor and Emotiva XPA5 power amplifier. Presently I have the front FS B&W 683 connected through the XPA5 using Mr.Murthy's DIY I/C just received yesterday. Now the Humming/buzzing starts when the power amp is switched on but the AVR (used as pre) is on the standby mode or completely switched off, but the moment the Onkyo is powered on the Humming/buzzing goes away. So kindly provide some solutions or links if the you feel it has been discussed else where.
Thanks:sad:

 

[ravidharap]

can be earthing /grounding problem with specified devices.pls check the earthing / grounding.

 

[sbg]

Also, if its a two pin plug, try reversing the and check.

 

[avr]

Thanks Ravi and sbg,
I think I have zeroed in the problem. The problem I think is with the I/C, I have a component video cable which was used for my projector earlier. Since it is a RCA cable I switched it with the I/C given by Mr.Murthy, and surprisingly there was no humming/buzzing from the speakers. This was completely unexpected as the cable is a video cable, I than talked to Mr.Murthy, he said perhaps the cable he sent me was not shielded. Now I m sending the same back to Mr.Murthy. Although the SQ with the component RCA cable leaves much to be desired but the problem of humming/buzzing is solved for the time being.
Thanks