This tube preamp uses combination of bass sound with drive distortion sound together. This technique gives punch and pulsation on every position of gain knob. Optic type compressor is used in the preamp. How to set-up compressor you may read here: http://victor-custom.com/kak-nastroit-kompressor/
5-band EQ with 2 semi parametric banbs. Fx loop footswitch contlolled.
XLR out can send direct bass guitar signal(active direct box) or preamp signal depends on switch position.
Tubes: 2x12AX7 / ECC83