Hi LG1
If you have $30 to risk, order on-line from Parts Express a Behringer USB DAC/headphone amp (the U-Control UCA202). It has a captive USB cable (plug into the IMAC) and RCAs out (to connect to your reciver).
If this improves the sound,then you'll know that a quality USB DAC will make a major improvement. "Quality" USB DACs, new ones, start at about $150 and go over $2000.
Mike19
If you have $30 to risk, order on-line from Parts Express a Behringer USB DAC/headphone amp (the U-Control UCA202). It has a captive USB cable (plug into the IMAC) and RCAs out (to connect to your reciver).
If this improves the sound,then you'll know that a quality USB DAC will make a major improvement. "Quality" USB DACs, new ones, start at about $150 and go over $2000.
Mike19