I may be able to help. I have been listening to the Digital Preamp/DAC since last Thursday.
1. Maximum output voltages for the balanced and unbalanced preamp out.
Per the owner's manual:
RCA outputs
The RCA outputs have a full-scale level of 5.6 volts zero-to-peak at maximum volume. These outputs are designed to drive loads of 2kΩ or higher.
XLR outputs
The XLR outputs have a full-scale level of 11.2 volts zero-to-peak at maximum volume. The XLR outputs are designed to drive balanced loads of 4kΩ or higher or differential loads of 2kΩ or higher per hot/cold output.
While the unit’s XLR outputs are balanced, they are not “transformer-like.” This means if you connect the hot side of the XLR as the signal and connect the the cold side to ground, the net level will be halved and some differential advantages will be lost. If you wish to connect the unit to an unbalanced XLR input, we recommend you use the RCA outputs instead with appropriate cable adapters.
2. What are the control options handled by the remote. ie, inputs, volume, balance, etc.
Remote controls volume, screen brightness, and input selection. Touch screen on the unit controls input and volume. No balance control.
3. Physical size of the preamp.
Approximately 17" W x 13" D x 4" H