Rate: Controls the rate of the low-frequency oscillator (LFO) for the flanger, from glacial to space invaders. Controls the input sensitivity in Dynamic mode.
Depth: Controls the maximum LFO sweep. In Step mode, the depth control chooses downward steps, upward + downward steps, upward steps, or random steps. In Dynamic mode, this controls whether the flanger sweeps down (less than noon) or up (greater than noon) based on the input signal.
Mix: Controls the blend between the dry and flanged signal. Equal mix is at 12 o'clock.
Hint: Pitch vibrato is available with low Regen settings and fully wet mix.
Regen: Adjusts the amount of flanged signal fed back into the modulation. Zero feedback is at noon, clockwise increases the positive feedback for a standard flanger sound. Twist this knob counter-clockwise for negative feedback and a unique "inside out" flange.
Step: The flanger LFO is forced to "step" to eight different values for transforming robot sounds. Sweeps either up, up + down, down, or random. The random mode is similar to a synthesizer "sample and hold" effect but with flange instead of filter.
Sweep: Traditional flanging is found here. The LFO for the F.13 is actually a "hypertriangular" waveform, so that the flanger spends more time in the interesting portions of the sweep.
Hint: Set the Rate control at zero for "filter matrix" style manual flanging. The Depth knob controls the flange position.
Dynamic: This one is kind of unusual, even for us! The flanger delay time is set by the volume of the input signal. The Rate knob adjusts the sensitivity, to allow for different pickups or effects before the F.13. The Depth knob controls which direction the flanger will sweep when it hears the input signal. Don't say we didn't warn you.
The F.13 features true bypass switching using a latching relay and a soft-touch bypass footswitch. The F.13 will power on in either bypass mode or effect mode (useful if you are using the pedal with a remote bypass switching system.) Hold the footswitch at boot to toggle between bypass and effect startup modes. The pedal remembers your settings when the power is removed.
Note: certain early Radical Delay pedals have a mechanical 3PDT bypass switch rather than the relay switching. Relay equipped pedals blink the LED twice rapidly at power-on.
The F.13 requires a 9V DC power supply with a 2.1mm pin, center negative. The F.13 is not designed to be powered on supplies higher than 9V and does not use a battery. The F.13 should work fine on a multi-pedal "daisy chain" connector, but if you encounter excessive noise or hum try a separate power supply.