Sonica DAC full upgrade...

[Coris]

Showing here my fully upgraded Sonica. New designed, and fully linear power supply, clock system battery powered, improved DAC power system, and the fully differential (OPA1632 based) output module for both RCA and XLR out (the two available DAC output pairs are tied together). Also some improvements on USB input board.

The new clock system it use two Epson oscillators (27Mhz for main processor, and a SAW type 100Mhz oscillator for DAC chip.
Very surprisingly the clock system upgrade it is decisive for the final touch in sound quality improvement. I did it this clock replacement in the end of the whole improvement process, after all upgrades it were in place. Lifting in sound quality after replacing the DAC oscillator, it is obvious.
Some words about my linear PSU. It include (beside the main power regulator), four ultra low noise TPS7A regulators, as follow: two for the +/- power rails for analogue circuits, and two pre regulators for DAC power rails. Very large filter capacities are also on board for digital section regulator, as for DAC pre regulators. I used the original HF main AC filtering cell, and I added (on LPS board) a DC blocking filter. The transformer winding designated to the digital section is double shielded, and grounded. The very low amount heat it is dissipated through the chassis cover (thermal connections by thermal pads).
How it sound all this? Over all expectations...

P.S. The picture hereby it was taken with the device in function. Therefore are placed the small heatsinks on the LPS regulators. New and improved LPS version available.