Morley PWB rebuild

[laurie]

A while ago I bought a Morley PWB (Power Wah Boost) pedal for cheap. Non-functioning. In really rough shape. I'm in the process of rebuilding it.

The power supply has a really old 110V 2-prong power cord (no ground) that has to be upgraded. The internal transformer is 28VDC giving around 40VDC voltage to the circuit.

Rather than replace the power cord with a 3-prong grounded cord that "tethered you to a 110V outlet", I'm going to attempt to power it from a standard 9VDC supply using a thing called a buck-converter.

This is the original circuit:
.

PWB_PSU.jpg (38.94 KiB) Viewed 652 times

.
.
This is the buck-converter:
.

Buck_converter.jpg (215.11 KiB) Viewed 652 times

The converter was purchased from Amazon:
https://www.amazon.ca/dp/B08D7KSCDN

I don't know how it will work out... I'll keep up a commentary here.

[laurie]

So far I've dismantled the pedal, removed the mains transformer, and swapped the old electrolytic caps including swapping the 1uF caps in the audio path for metallized polyester. Also cleaned and lubricated the pot. Next step is cleaning everything.
.

PWB_board.jpg (291.69 KiB) Viewed 651 times

[laurie]

Both the wah and the boost are controlled optically. There is a bit of mechanical realignment needed.

I'm sure it won't be worth enough to justify the time I'll put into it, but I couldn't see it go into the parts bin without fixing it.

[Pepe]

Wow, this thing needs 40V?

[laurie]

Wow, this thing needs 40V?

Indeed.