Yes, it took a lot of work and a lot longer then we had expected, but AVA can now offer optional balanced line inputs on all of our large chassis power amplifiers (Fet Valve 600R, Fet Valve 400R, Synergy 450 and Synergy 300)
The option price is $200 for balanced line inputs only, $250 for switchable balanced line and RCA single ended inputs.
The balanced line option includes Neutrik gold contact XLR connections, a new tiny stereo differential operation summing board that mounts directly on the XLR jacks (no "pin 1" issue) and a separate regulated power supply board, transformer and all, to power the summing board.
It was an enormous project to design a summing board that did not affect the awesome sound quality of our power amps, but its a done deal now. The active circuits are direct coupled in to out, no capacitors in the signal path, and include a time delay relay to protect the amp from on or off transients. It s a really lovely and tiny bit of engineering work.
We can supply these amplifiers with true balanced line inputs right now, just what you need to run one from those high tech digital DAC/Preamp units.
Sorry, the balanced line input option is not available as a retrofit for older AVA amplifiers. It required tooling new back panel metal and swapping back panel metal is a VERY labor-intensive operation.
Please call me for more details. 651-330-9871
Frank Van Alstine