the Opto-Trem

One of these developments wich come from needing one. When requiring a trem for one song only in a full set I found out that in my complete arsenal of effectsI could either choose for the Shin-Ei Resly/Phaser tone or a Kay tremolo. Both boxes I don't feel too much like to take em on the road. Another option was to assemble another Wob for the job. Wob;s take a rather long time to build and, in the situation I was in more than half of the Wob's wicked functionality would be left unused. However, from a soundperspective this was an interesting option. Therefor it was a pretty easy choice to copy the wob's designfiles, excerpt one of it's 2 channels and put that back together in a far smaller box. Printed circuitboard design for the Opto-Trem was done in approx. 2 hours. and the prototype finished in a week. From a cost perspective the Opto-Trem is an interesting option when looking for a simple optical tremolo pedal.

The Opto-Trem trem's between unity gain and close to no signal. If required, because trem's often give the impression of taking the overall level down, the level can be lifted to be a little (or a lot) above unity gain.

The Opto-Trem's LFO (Low Frequency Oscillator) can be tapped from 2 points. Therefore the modulation wave used for the trem effect is either Square wave or Triangle wave. Since both waveforms are part of the lFO design there was no problem with applying this option. Where the Squerwave gives a much stronger modulation the triangle has a more smoothed effect, especcially at lower LFO settings. As result of the relative slow response time of the opto-element used neither of the 2 waveforms will modulate so fast that the volumechanges result in distortion.

Opto-Trem Tech Spec's:

Description: Single channel amplitude modulator - Power Supply:....... 9Vdc battery or 9 volts DC adapter (center negative)
- Current Consumption:.......Approx 30 mA
- Modulation Modes:....... Square or triangle wave
- Bypass:........True Bypass
- Control's:.........Rate and Depth.