From a 1973 Eko catalog about the
“Wha-Wha — Distortion — Treble-bass booster —
Repeat percussion — Volume control. All these effects in one pedal. Play
it for a single wha-wha or distortion effect, or in combination with
other effects and you will discover a new world of exciting sounds.”
“I bought this because I assumed it was the same circuit as the one in the Vox Ultrasonic/Cheetah etc … Repeater, Distortion, Treble/Bass Boost and Wah. It’s actually slightly different, at least where the distortion is concerned. If you want that Spacemen 3 sound this’ll get you on your way.”
These may have been true bypass from the factory.