Tube summing mixer, 2x10 inputs, transformer balanced

This is the listing for passive summing mixer made with custom PCB and fine 1% tolerance metal film resistors.
After the passive summing goes 1:12 mic input transformer (taken from Shure M67) and after the transformer goes tube amplifier interfacing UTM3510 output transformer.

Both make-up amplifiers made with high tolerance components to make them as much identical as possible, supplied with soviet era 6Н23П (6N23P) tubes (ECC88 direct alternative), but feel free to step up and source ECC88 if you want, that can be an improvement.

The chassis is taken from old Digidesign 888 I/O unit, 2U size, sits perfectly in rack.

The power transformer is magnetically shielded, so the operation is as noiseless as possible.

The power transformer has two 17V secondary windings not used if you have any plans to add anything inside.

The mixer has 10 balanced inputs per channel, two channels.
The mixer has two outputs per channel - one passive, right after the summing network (A, see pictures) and one active, after the make-up stage (B, see pictures).
Thus, summing 10 stereo busses, balanced I/O.

Sounds fantastic, only one has ever been made.

No power cord or XLR signal cords or summing PCB supplied, mixer only.

Check the demo on youtube @HappinessMastering.