Musictronics Mu-tron Octave Divider

“The new MU-TRON OCTAVE/DIVIDER make the full harmonically rich option of “playing in octaves” available to all horn and stringed instrument players. This live effect is created by newly developed circuitry that analyzes the original signal and “pairs” it with the note one octave below, matching tone and color and dynamics over an execptionally wide range.”. As stated by the original user manual of the octave divider! The mu-tron was probably the first pedal with such effect and appeared during the 70s.

The operating principle of the mu-tron uses flip-flops to divide the frequency. The original mu-tron doens’t use batteries, but is instead powered by AC mains power (as most units were sold in the US, this means 110V). The circuit operates with +12V and -12V, which makes it difficult to replicate the circuit with regular 9V DC power (or a 9V battery).

The BYOC Divided OCtave clone uses a MAX1044 IC that is able to create a dual voltage supply ±9V. The workings of this IC are explained in this electrosmash article of the Klon Centaur. Using the circuit in the Klon Cenataur, a supply voltage of ±13.5V is possible.

The LT1054 is recommended to use instead of the MAX1044, as it can deliver more current, can deal with higher voltage, has protection circuitry and the opinion seems to be that it produces less noise.