FAQ - Trouble Shooting ...

LED light will not come on when the cable is inserted?: 1) Make sure the battery is good.
2) You must use a cable with a mono plug and not a stereo plug. A stereo cable will not power up the preamp.
3) If you change the output jack and wire it incorrectly the preamp will never power down.
4) Make sure the connector is not shorting against a conductive wall or the preamp will not power down and the LED will not light.
5) LED damaged.

LED fast flashes with good batteries?: 1) The pickup common is connected to ground pulling the battery voltage down.
2) The battery contact is very marginal.
3) The input ring to jack ground connection through the mono plug is very marginal.

Scratchy Controls? or Lots of distortion? or Pops with the Z-Mode Switch is Changed? or Shuts off when the bass is turned up?: 1) The pickup common is connected to ground amplifying only 1 polarity of the input signal.
To fix - start with a Touch Test and if you have a DMM do a Meter Test

Pops when the string contacts the pole pieces?: If the strings are grounded and the pole pieces are at the pickup common voltage (1/2 the battery voltage) when the 2 come in contact the preamp output will slew very quickly to the rail creating an extremely loud pop. To fix, remove the pole piece electrical connection from the pickup common normally located on the bottom of the pickup and electrically connect these the pole pieces to ground.

Pops when I use my coil splitter switch?: Coil splitter switches are wired in front of the preamp. If you wire the coil splitter as is common for most preamps it will pop when you change to single coil mode. Remove the ground wire from the switch and use the pickup common wire instead. Do not ground the pickup common wire...

No Output but the LED Battery Meter works?: 1) Your pickups have 3 wires (like on a Geddy) you need to connect the shield to the ground and the coil wires to pickup hot and pickup common. On some pickups the pickup common and the shield are both black and it can be hard to tell which is what function. On a Geddy jazz bass the pickup common will most often have writing on it like the hot lead.
2) Bad soldering job when changing the output jack
3) Broken wire

Batteries goes dead in the case?: 1) If you change the output jack and wire it incorrectly the preamp will never power down and your batteries will drain while the bass is in the case.