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.