This is the revised version of my Blue Warbler Envelope Vibe/Tremolo.
The vibe mode is based on Tim Escobedo's Warbletron (a simple two-stage phaser) with some adjustments to create a watery vibe effect with less pitch vibrato than some other pedals based on that effect. And it's even got a little bit of a lope/asymmetry like a good vibe should.
The tremolo mode simply lifts the out-of-phase signal and is similar in implementation to the full-range tremolo effect in my Cardinal tremolo.
The Sense controls an envelope signal that interrupts the oscillation to add a little chaos. You can use your picking dynamics to keep the attack of notes modulation-free, which vibrato or tremolo will appear on notes that are held longer, similar to a singer's vocal technique.
About the new version:
The original was my 50th pedal, build and designed for a DIYSB contest. The redesign takes the same basic idea -- an envelope signal interrupts a simple sine-wave LFO to add some chaos to the modulation -- but greatly improves many aspects of the pedal.
The dry path now uses a MOSFET for better input and output impedance and a bit more headroom and clarity.
The rate now has a wider range, including slower settings; the sense control no longer affects the rate control (and no longer shuts off the LFO in some settings); and the depth control works much better, no longer turning the LED off at low settings (so you get a full range signal). The tremolo mode has also been improved, with a simpler implementation and no volume drop.
Finally, the envelope control has been redesigned to allow simultaneous control of the threshold, decay, and bandwidth. At low settings, the decay is extremely short (almost instantaneous), the threshold is high, and less bass gets through (good because bass frequencies tend to trigger envelopes harder than treble). At higher settings, the decay is longer, the threshold is very low, and more bass is allowed through. This allows better fine tuning for different pickup strengths than a straight threshold control would allow.
Although this isn't built on the forthcoming JMK PCBs board, it is very very close to the project. The PCB might have a few extra surprises and options, or a few different values, but this is pretty close to what it'll sound like.