Steve,
Hope you call it the ZTONE.
I have an idea for the tube EQ :

Gain (volume) control for the right knob, treble control on the left.
Wouldn't it be wonderful if you incorporated the Torii treble control as well? I have been involved with Decware for 15 years and have read and heard the number one problem and complaint with audiophiles in the digital realm: the treble sucks!
Why not offer an affordable product that finally solves this problem once and for all! And no trade off : turn it off for audiophile recordings, crank it up for garbage recordings like rock.
I'll admit 2 knobs doesn't look as sharp as the balanced appearance of the black box but this isn't about looks.
No doubt this product would cancel many Zbox sales but who cares, you can charge more for it than the Zbox. :)
Sincerely,
Corey