Cardinal Tremolo

The Cardinal Tremolo v1 is a tremolo effect evocative of the harmonic tremolo effect that was available from certain Fender amps, from 1960 to 1963. These amps include:

• The Fender Concert,
• The Fender Pro,
• The Fender Showman,
• The Fender Super, and
• The Fender Twin

Per the build notes document, this is a circuit by Jon Patton and was extensively influenced by previous tremolo pedal designs. In the build notes, Jon credits:

This circuit is based in part on RG Keen's Pro-Vibrato schematic. The LFO was adapted from CultureJam's Shoot the Moon Tremolo, which in turn adapted from Dann Green's Tremulus Lune. Thanks to Jimi Photon for the inspiration and samhay, ~arph, and duck_arse for discussions and suggestions on DIYStompboxes.

Controls

• Knob 1 - "Depth": Sets the depth of the volume swell of the tremolo
• Knob 2 - "Rate": Sets the speed of the swell of the tremolo
• Switch 1 - "Select": Allows selection between Harmonic and Standard Tremolo functions

General Information

http://1776effects.com/wp-content/uploads/2015/03/Cardinal-Tremolo.pdf

We currently only have Version 1 of the Cardinal Tremolo pcb. It would appear that 1776 Effects has also released a Version 2. The pedal makes available both the amplike "Harmonic" tremolo, as well as a standard volume-swell tremolo effect. A quick look at both the schematics for v1 and v2 suggests that the only big difference between the two is that the Version 2 board takes what are trimpots (set-em and forget-em) on the board and exposes them as full potentiometers.

Schematic

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Additional Sources

• Build Instructions Cardinal Tremolo, v.2