I purchased this CD50 from the original owner who had Resolution Audio replace the Philips CDM12 transport mechanism last year. The CD50 uses 4 Burr-Brown PMC63 'K-Grade' DACs; the CD50 is fully balanced from the digital domain through to the analog outputs. The single-ended outputs are derived from the balanced outputs. The analog domain volume control adjusts in 0.5dB steps with 60dB maximum. Caveat - the standby and phase functions do not work. I contacted Jeff Kalt, president of Resolution Audio, who advised my unit did not have the software upgrade to perform these functions. He can perform the software upgrade for a nominal fee, but I did not deem it necessary. At my asking price I'll include a 3-foot Signal Cable digital power cable. I accept payment via USPS money order or PayPal [add 3%].