Just bought a new Marantz PM4001 and today connected it to Wharfedale Diamond 8.3 speakers. Right channel sounds fine but left is terrible, low and tinny sound. Very strange. Have checked all connections but with no joy. Just seen in instructions that the speakers are 6 ohms, and the marantz intructions mention that the amp is only for speakers from 8 to 16 ohms. Is that my problem??