Phase Shifter Module

The Pittsburgh Modular Phase Shifter is a complex, 16 stage, analog effect module designed to expand on the classic swirls, rich swooshes, and doppler effects associated with the phaser. The Phase Shifter has a single 16 stage audio signal path to create a very rich, full sound. Phased audio outputs are tapped from stages 7, 8, 15, and 16.  Stages 8 and 16 each have a mix output that allow the phased signal to be mixed with a dry signal. 

Four CV inputs, an onboard LFO, and multiple CV routing options allow for maximum flexibility and extremely deep modulation options. The CV inputs are split into 2 groups. The first group of CV inputs controls either all 16 stages or just stages 1-8. The second group of CV input controls stages 9-16 and is switchable on or off. All CV signals routed to stages 9-16 can be inverted. Resonance can be positive or negative and the module will self oscillate in either direction.
 
To modulate the phase shifter circuit, the module includes a wide range low frequency oscillator. The LFO range varies from 1 minute per cycle to well into audio range. The triangle wave of the LFO is hardwired to modulate the frequency of all 16 channels of the Phase Shifter. External modulation sources are handled using 2 sets of CV inputs. Each set includes an invertible, uni-polar CV input that accepts 0v to 5v modulation signals and a bi-polar CV input which accepts -5v to +5v signals. All of the modulation CV inputs can be used simultaneously and can be mixed with the internal LFO to create very complex frequency modulations. Stages 1-8 and 9-16 can be modulated together or independently using the available switches and CV inputs.