I added the ZBOX to the chain last night.
I replaced an old Baldwin tube in the ZBOX with a new JJ 12AU7.
I placed the ZBOX right after the Bel Canto DAC.

It sounds nice.  Very nice.  David Gilmour's Strat sounds very smooth.

I'm not sure if it is better than the blue Torii or not.  It is hard to compare.  I do know that that AVA can get some nice low end without a subwoofer.  The Torii needed the subwoofer and man, was that sub hard to integrate.  But, I used a Yamaha sub and maybe that was the problem.

It would be nice if I could place the ZBOX before the DAC somehow.  I don't know what that would do to the sound.

Let's see what that ZBOX can do after the new tube burns in for a time.