Guitars of Love


Building a handy passive bass cut pedal to get clearer overdrive sounds

One of the problems with Overdrive pedals and driving amps hard is that too much bottom end sullys the sound into a durge. By selectivly reducing the bottom end of the guitar, the OD drives much harder in the tops leaving the bottome cleaner, and the treble compressed. G&L incorporated this type of circuit into their guitars and this simple passive circuit is based on this, but with the flexibility of 6 different settings, and the option of turning the pot right off for a more marked effect.

To the right is the 'equivalent circuit' of the pedal. By passing the PU signal through a small capacitor and regulating the amount of bypass with a 1 Meg pot, a variable bass cut is achieved.

Here is the actual circuit of my bass cut pedal. It uses a 6 way double pole rotary switch to select a wide range of caps in conjunction with a 1 Meg log pot, and also the option of switching the pot right out. The original G&L guitars also included a treble cut cct which I ignored as it is assumed the guitar already has tone controls. Click on the schematic (or here) to download the hi res pdf:

Interior detail:

The finished unit. The LED is there just to indicate when the pedal is engaged and uses about 1.5 mA from the 9V battery (4K7 in series from the true bypass switch).