1976 I.W. Turner Square Wave Generator Electronic Music Lab Creator of Sonic Wave Theremin

Very rare Square Wave Generator module made by I.W. Turner, the company which made the infamous Sonic Wave theremin used by Jimmy Page. As you can tell, the shape of this module is even consistent with the Sonic Wave. Modules such as this and the Theremin module (for sale, please see my listing) were originally developed by I.W. Turner for demonstrating such technologies to students in an educational setting in the 1970s. Specifically, this unit is from around mid 1970s, as the pot dates signify 1975 and 1976. This circuit and handwriting were most likely done by Donald Tillman.
The unit uses a nice 1976 Motorola MC1458CP op-amp and CTS pots. It also appears to use a CDE capacitor, the same that can be found in 70s guitar pedals such as the mid-70s Electro Harmonix Black Finger.

Middle button on this unit has no effect.