BYOC Analog Stereo Flanger

A few months ago I built another BYOC pedal, this time an analog stereo flanger. I used a mod that I found on their forum so it can behave like a chorus, too. Flanging is a type of phase shifting effect in which a dry signal is added to a time-delayed (usually <20ms) copy of itself. The resulting signal has peaks and troughs in a harmonic series, and sounds like a 'whoosh', or a jet plane taking off.

The mod calls for a 2048-stage bucket brigade delay chip (MN3208), as opposed to the stock 1024-stage BBD (MN3207), so you can increase the max delay time of the delayed signal to the 20-60 ms range, for more of a chorus effect.

This one was pretty easy to build. I just sorted the parts, soldered them into the board and assembled the enclosure. It worked the first time I fired it up, and it sounds great.

There are four knobs and a toggle switch (I know, they're not labeled, but I already know what they do). The circuit has two bucket brigade chips in parallel and out of phase for two pitch-shifted signals to be added to the dry signal, similar to the way the Electroharmonix Electric Mistress worked.

The toggle switch takes the second bucket brigade delay chip of of the signal path, so it's more like the MXR flanger. The knob in the top left corner controls the rate of the low frequency oscillator sweep. The knob below that controls the depth of the LFO. The knob next to the depth controls the regeneration of the signal, i.e. how much of the signal is fed back into the delay line.

The knob in the upper right hand corner allows you to manually control the sweep when the depth knob is turned all the way counterclockwise. If the depth knob is not turned all the way clockwise, it acts as the "delay time" knob. If the depth knob is turned all the way clockwise, the manual knob has no effect.