I think I remember a situation like this before, it's caused when the power supply is turned on and then plugged into the main unit before waiting for caps to bleed down.
It blows the SS rectifiers and distortion is the outcome as well as no volume. I don't have a way to send you the test sheet to read out with VOM. I suggest you telephone Glenn Buckley at Aesthetix, the last number I have for him is 805-529-9901.
You have a very fine preamp, I used one for about a decade. Proper tubes and tweaks really make the Callisto sing, as well as the various cap upgrades that Aesthetix offered since that model.
Also, if yours is a very early model, the fuse in the power supply blows quite easily. One of the updates from the factory removes it in favor of a copper jumper. I don't suggest you do this yourself unless you have experience. Again, run that by Glenn.