Must be a fine amp Rob. What's the purpose of Sunfire's Current/Voltage Source output options?
Yes the Sunfire's are nice amps but i don't think you will like the explanation
. According to a whitepaper by Bob Carver, you can create a "Tube Amp" sound by increasing the impedance of the speaker outputs "Current Source" (as I recall they use a 1 Ohm resistor). They suggest bi-wiring the speakers with the Current Source to the Tweeter ("warmer sound") and the Voltage Source to the bass/mid drivers.
I have played around with this a bit and currently use the above config with my Revel Studios. The differences are slight but the concept is interesting. It is easily bypassed by running from the Voltage Source outputs only. Here is a link to the Sunfire Whitepaper