Electro Harmonix Polyphase EH7100B
Phase shift with envelope control (1976)

Analog pedal guitar effect from the seventies. It is basically a phaser with envelope follower on the filter

OVERVIEW traditional EHX metal solid shaped box with direct AC power chord, later reissues have external PSU.

Back panel terminal connectors:
- sound mode selector switch
- audio input
- dry out
- effect out

SOUND basically the polyphase is a 6-stages phaser working with 2 particular main modes:
- standard phaser
- driven by EG following process
First mode uses the internal LFO for a really sweepy and marvelous spatial sound very harmonic and a present EQ, and best of all, it doe not eat up all the sound bandwidth. The Envelope EG mode is gated by guitar peak and retrig the amount of phasing.

 

FUNCTIONS Main panel has a frontal footswitch bypass and 5 frontal knobs for sound edit:
- Feedback adjusts the resonance balancing between a more pronounced sound and dry
- Mod Rate changes the LFO frequency speed
- Env Sens sets the Envelope follower threshold
- Env Modulation sets the modulation amount for envelope following process

 

 

RELATED FAMILY:

Stereo polyphase a modern remake with some new features like LFO wavefor, pedal input for expression control VIDEO

 

AUDIO DEMO

guitar demo 1 guitar demo 2

 

YOUTUBE VIDEO CLIP SELECTION demo1 demo2