Odd Topaz Toplift/Tremolo Reversed

[goldstache]

My buddy Taka punted me this old Topaz Toplift/Tremolo Strap clipped Guitar Effect.
It was DOA and needed overhauled, but here's some info for those interested.

Resistors Carbon Comp
Caps made by Hunts
Transistors Mullard OC71's

I left off the switching arrangement in the schemo's but in essence it lifts ground connections to portions of the circuit to eliminate 9V battery draw in bypass mode. Then you got a selection for "toplift" Treble boost no Oscillator, Tremolo mode grounds Q2 trimmer connection for feedback oscillator deal.

Reminds me of the Vox Repeater kinda chop, but input is to the Emitter of Q1!  First time for everything. Functions about the same with input cap inserted to Base of Q1.  Base input allows for a little better function with all types of pickups and avoids noise with guitar volume grounded. Just a weird thing of note.






I breadboarded it after the circuit trace, mainly to understand the dang thing. 

Swapped the Beans and went with 2SA15's (OC44 variant) and silicon on the way out for Q3 BC506.
Then some part tweaks for stability and better operation range (V2 schematic)

I'm assuming it's just good ol' positive feedback oscillator kinda arrangement. But figured I'd plop it here for others analysis!

Thanks,
joe