A Challenge for Vintage Pedal Gurus.

[stuznu]

Hi all, I am seeking help from those forum members with formal electronics training and/or experience with late 50's or early 60s equipment. I am not sure if describing it as a pedal is appropriate, as it does not have a stomp switch. Instead it has  a power switch on top of the box and a twist switch that operates a 'leaf switch' inside the box.
On the front it has two controls consisting of 2x 100k potentiometers - one control knob is missing,\.

The circuit board looks like fibre glass while switches and knobs are  bakelite. The casing is a combination of metal and fiberglass.
The pedal is obviously a handmade pedal from the Soviet era, and I am fascinated by it to the point where I would love to repair and hear what it is capable of. Some of the capacitors have Tesla markings and there are four transistors on be pcb. Switches are made of bakelite! Sides of the casing are made of fibreglass and metal.

The solder side of the pcb looks like some point to point connections were made. I am certainly no expert - it could just be a case of dodgy workmanship.

I have attached some pics and look forward to any constructive contribution to getting this effects pedal working again.

My question : An idea what pedal this is? Fuzz, distortion ...??
Any educated guesses??

I have tested the potentiometers and one of them seems to have failed as it is unable to give stable reading in any direction.
I intend cleaning the pots first, then trying the pedal with a 9v battery, and use a DVM to investigate the current flow through the circuit.

[amptramp]

The construction here is large enough and the circuit appears to be simple enough that you could trace out the schematic.  The major difficulty would be getting the pinouts of the transistors but that may become apparent just from the connections.  Follow the signal path from the input jack and it should lead to the output jack through all the devices.  You should identify the power connections as well and determine if the devices are NPN or PNP.

It may not turn out to be one of the standard circuits at all - possibly just a booster design with some distortion capabilities.  If you are able to identify it later, so much the better, but getting the schematic right is more important.

[GibsonGM]

That looks very DIY to me   

[Hatredman]

PCB looks ruined. If there are any tracks missing/lifted, it may be imposdible to trace.

Any pics of thr inputs/outputs?


--
Scarlett Johansson uses a Burst Box with her Telecaster.