This was a freebee from a friend that did not care for the small stone sound in general. It needed a bit of cleanup and a switch replacment (which I took from a broken version 3) and it was good to go.
The version 2 came out in 1979 and the circuit was not changed much from the version 1. It still used the EH1048 Operational Transconductance Amplifiers (OTA) chips. The Small Stone is a 4 stage phase shifter with one additional stage for feedback, which can be activated using the “Color” switch. At the time the only pedal that was compaired to the Small Stone was the MXR Phase 90 but instead of OTA’s it used matched FET transistors.