Both sources output impedance around 300 ohm, input impedance on power amps 100k. Output stage is the whatever is in the Assemblage DAC-2, phono is the output stage of the Pearl phono.
I talked to a couple of TVC makers including John Chapman at Bent, no one thinks it's a great idea to try and drive that much cable with TVC/AVC. Oh well, keeping the rack between the speakers really doesn't sound very good.