The Harmonic Tremolo is adaptation of the beautifully elusive Fender Brownface era Harmonic Vibrato circuit. Fender’s “Vibrato” is actually a Tremolo effect (modulation of volume or amplitude). However, in the early 60′s, Leo Fender developed a much more interesting version of Tremolo where the signal was split into treble and bass bands, and these two paths were amplitude modulated (tremolo) with out-of-phase LFOs.
The result is a sweet, throbbing tremolo with a side of phasing. The treble/bass crossover is not perfect, and when the signals are recombined, the overlap creates a phasing effect when modulated. The sound is chewy and fluid, without the annoying whooshes that come with traditional phasers.
The unique Balance control can vary the modulation voicing from warm and throbby to crisp and shimmery. The Intensity knob controls the depth of the modulation and varies the waveform from smooth to choppy.
Relay-based Bypass System
The Harmonic Tremolo features our most sophisticated and functional true bypass system to date. Using a PIC microcontroller to drive a gold-contact latching relay, the switching is quick, quiet and reliable. A MOSFET is used to mute the effect output while the relay makes the switch, and an opto FET isolates the effect input and insures a smooth transition from bypass to effect. Premium power filtering and signal buffering are all seamlessly integrated into the bypass system. Oh, and it reverts to bypass if power is lost, insuring that you don’t lose signal at the wrong time.
Momentary Bypass Mode
The Harmonic Tremolo can be put into “momentary” mode where the effect is triggered only when the footswitch is held down. To enter Momentary Mode, leave the pedal in bypass for >3 seconds, then enter the sequence Tap, Tap, Hold and the LED will blink indicating the Mode change. Repeat to reverse, or unplug/plug the power cord.