Hum in KRK RP-5 connected to Delta 1010LT

Configuring for the first time - help?

Hi-

I just purchased an M-Audio Delta 1010LT. Using KRK RP-5 powered monitors. Connecting via RCA unbalanced cables. Using PC, Athlon-based.

Here’s the deal. I was able to configure the stereo monitor mix in the M-Audio control panel, no problem. Set the output level to either consumer or -10dBV. And I get good quality sound out of the monitors - BUT, if I increase the volume control on the monitors above the minimum (-30dB), then I hear a hum in the monitors. If I keep it at the minimum and get my volume through the sound card settings, it’s okay. But I’m guessing that this is not correct.

Any ideas as to why I am getting this hum? Could it be noise being picked up by poorly shielded cables? I kind of doubt that, but I’m trying to figure it out.

Thanks!

Do both the monitors and the PC have a grounded power connection?

In that case you must use signal cables with the shielding connected only on one side (to prevent a ground loop that will pick up hum).

Or, if the monitors have a switch labeled “ground lift”, try using that.

I was also getting a hum in my Rockit 5s. After turning stuff off and on and unplugging one thing at a time, I found that it was the CRT monitor. I placed a 3-pring to 2-prong converter on the TV plug and it got rid of the hum.

Hunt around and good luck.