I will be adding to this page as I answer questions from bassists.
Q: Is the volume control on the input, or the output, of the preamp?
A: The volume control is on the output. I put it there because a potentiometer on the input would interfere with providing a high input impedance for upright bass use.
Q: What does the 6 V p-p input range mean?
A: It means that the input signal can have a maximum of 6 V from the bottom of the waveform to the top. Working out the math, this corresponds to a sinewave of 0.707*6/2 = 2.1 V RMS, or 20*log(2.1) = +6.4 dBV
Q: Can I put this in between my preamp and power amp?
A: It would help to look up the input sensitivity of the power amp. If it's less than 2.1 V RMS (as explained above), then with the attenuators turned all the way up on your power amp, the amp will clip before the preamp does.
Q: Can I mount the circuit board inside my bass?
A: Please contact me if you want to do this.
Q: Does the battery indicator LED work with the external power supply jack?
A: Not always. It was designed just for checking the battery.