At the moment, I don't have an AC car to look at, but you might be able to get shorter belts and run them from the crank pulley around the adjusting pulley, bypassing the compressor. I don't know if the compressor pulley would get in the way, though.
You might check to see if the compressor clutch is getting power. if there is no power to the clutch, the compressor pulley should spin freely and not make any noise.