Bass Drum Mods

Bass Drum Tune:

Its a simple replacement of R58 with a variable resistance. The values shown should give a tuneable range of 20-240hz.

Bass Drum Envelope:

This is a control to give the frequency of the drum envelope modulation to bring some punch to the bass drum sound. Note the diodes are Germanium. Also the 10k log pot is used in the backwards direction.

Bass Drum Tone:

There is a first order LPF filter on the output of the bass drum oscillator, this will provide a frequency control for it. Simply replace R56 with a 50k log variable resistor.

Bass Drum Decay

This will be a bit tricky, it converts the existing dual oscillator TR606 bass drum into a single oscillator TR808 type circuit. R60,61,66 and C22,23,24 are all removed to acommodate the new components. Also the track leading to pin 5 was cut. For a mathematical description of why this works check out the root locus here.