Replacement cable for MIT Terminator3 interconnect

I recently replaced my Monster speaker cables with Kimber 8TC in 10' legnths. Shortly after I began to get a hum(60 cycle) when I turned off the amp/pre or when I muted the preamp. I switched out the preamp and the hum went away.
I put the pre in the shop only to find nothing wrong.

I put the pre back in and again the hum appears when shuting down or muting. I put a cheap interconnect in place of the MITs and the hum is gone. The bass however is flabby and the mids are less weighty. I'm certain the MITs were the problem. I picked them up for less than half price and they sounded excellent for the past 5 years.

Please suggest an interconnect for a price of around $125 to $150 that is a suitable replacement. My amp is an MC275 original and the pre is a C39 (both McIntosh).

Thank you for any suggestions of cost saving and good sound value.