Sounds like you might want to look at the Placette passive preamp. It's basically a volume control unit with one input--doesn't get much simpler or more transparent than this. FTAudio also seems good if you don't need a remote.
I'd also recommend either a DAC(EVS Millennium DAC, Kora Hermes, Modwright P3A, etc.) or send the Sony to someone like Ric Schultz at EVS to get it modified. Between this and the preamp I think your system will open up to a new level. Best of luck.
Tim
I'd also recommend either a DAC(EVS Millennium DAC, Kora Hermes, Modwright P3A, etc.) or send the Sony to someone like Ric Schultz at EVS to get it modified. Between this and the preamp I think your system will open up to a new level. Best of luck.
Tim