I recently bought a Marantz 1060 from a vintage stereo dealer. He assured me the unit was in perfect condition and had a good reputation so I generally trust that I have a good amp. HOWEVER, I have run into a problem that I could use some help trouble shooting. When I plug my turntable into the phono line, one channel comes through clear and loud and the other comes through very weak. If I turn my table's preamp on and run it through the AUX or TAPE line, both channels come through clear as a bell. I would like to use the phono on the Marantz and cannot figure out what is causing this problem. Anyone know what might be causing this?