The E-Follower 45B has three complimentary sections for converting audio source material to control voltage and gate signals. The top section is a fast response envelope follower and built in pre-amp with three gain ranges for modular, line and mic levels.

The second section is a Gate extractor with variable threshold and status LED. Peak voltages from the follower can be detected and converted to gate signals for triggering envelope generators, switching logic etc.

The third section is a voltage controlled linear Attack/Release envelope or slew limiter. The Attack and Release time durations can be voltage controlled independently or simultaneously, determined by switch selector. Primary uses for this section are smoothing or contouring envelope follower voltage transitions and as a VC slew limiter for pitch glide with independent up/down durations. Pulsing the input will also produce simple A/R envelope generator function for use with VCAs, filters etc.

e-flanger.mp3 Drum loop and envelope follower modulating the frequency of the Flanger module.

e-flanger2.mp3 variation on the above

ducker.mp3 demonstrates the gate extracter being used to create a ducker effect. Lots of other compressor/limiter type effects are possible in conjunction with VCAs. Side chaining is also possible if the source signal is filtered with the Fixed Filter Bank etc., pre-follower input.


Envelope Follower Section
1/4" input jack to Pre-amp and follower circuitry. Pre-amp output for boosted external audio signals. Gain selector switch for matching external signal levels. 1X for modular levels, 10X for line +4dBu, 100X for guitar or microphone. Envelope follower output for patching to A/R section for further processing. Follower output is normalled to the Gate input and AR input.

Gate Extractor Section
Comparator converts voltage from the envelope follower section to +5V gate signal with user definable threshold. Status LED indicates threshold.

VC A/R Envelope Section
separate attack, release controls work in conjunction with CV input to set the duration of the envelope or smoothing contour. 3 position selector switch routes the voltage control ENV CV jack to the attack, release or both. LED indicates envelope state.