The BP-7 is a Bass Preamp / DI with a drive circuit consisting of three separate gain sections, two of them being different CMOS devices. We here at Mozztronics don’t particularly like Blend and Volume controls as we think they are two awkward to “dial in”, you want a little more dirt, you turn the blend up, but then the volume is wrong so you have to adjust that too, what a pain, that’s why we prefer the separate Wet and Dry volume controls. It is still two controls, but much easier to use.

We split the signal from the Bass, one path goes through the DRY control, then it is mixed with the WET signal, and goes through the 3 band EQ to the output. The other path goes through the three separate gain stages (no diode clipping here), the Contour switch, and a LPF before being mixed back with the DRY signal before the EQ.

DRY is the volume of the original signal from your bass guitar.
WET is the volume of the dirty signal from the three gain stages.
DRIVE controls the amount of overdrive from barely on to full on shred
BASS is 30Hz, MID is 300Hz, Treble is 3hKz

Turn DRY up to get the level of your original guitar’s signal, Turn WET up for the desired amount of dirt to be added. Turn DRIVE up to get your desired dirty sound.
Low levels of drive added give you a lovely warm tone like those from valve bass amps, turn the drive up to add more distortion. Adjust the WET volume according to taste.
Once you have the mix done, you can then EQ the final sound with the 3 band amp style “cut” eq. This is the same as found in almost every guitar amp under the sun, so start with the three EQ knobs on full, and bring them down to taste.

But that’s not all, the BP-7 is also fantastic on guitar, turn DRY to minimum, and you have a great doomy guitar dirt box. You can even mix in a little of the DRY guitar signal to get different sounds.

Mozztronics uses the industry standard Boss style 2.1mm center negative 9V DC socket for the power supply connection.