Old board schematics

[roughshawd]

There was once an old electrician technician who made wah wah pedals for sale. His initials were probably JR, and he was building his fourth wah wah. There was such a demand for his pedals that he hired out to a big company named regal to make a bunch of different wah wahs, some that had fuzz boxes and other effects built in. His board #134-43 went in the do-wah-diddy pedal. After a long time the pedal stopped working and was tossed in the pile with the other 'broken' pedals. Years later, the pedal was salvaged by a millennial who was about to throw it away, and then thought his aging friend might want it. When it didn't work the old entertainer threw it in the garbage, where some person salvaged it again... It went from collector to collector across the city, and ended up in a junk box at an auction sale where this roughshawd handyman found it. The handyman knew they usually keep records of these boards, and decided to ask if anyone might know where he could get a schematic of the jr4 #134-43 board and a wiring diagram for a Regal Do-Wah-Diddy Wah Wah Pedal.

 

[bertus]

Hello,

You could make your own schematic using the traces (wich make the connections between the components) and the components on the component side of the board.
This technique is called reverse engineering.

You could also have a look at this thread about a foxx pedal:

https://maker.pro/forums/threads/restoring-a-regal-do-wa-diddy-by-foxx.282846/

Bertus

 

[roughshawd]

What does IOP on a board mean?

 

[ivak245]

Probably the brand on the phenolic board before it was etched.

 

[danadak]

Some solder problems :



Bottom pin 2'ond one in from left.



Top right pin.



Top right 3 pins.

Pics of top of board ?

 

[roughshawd]

Reflowed. Found out of spec caps, transistors in backwards, wrong resistors. I didn't have the right time caps... Got close though!

 

[roughshawd]

Original JR4 regal do-wah-diddy board... To bad there's no fuzzy blue or red box!!

 

[Iron Works]

Just so you know, I have the exact same PCB board JR4 134-43 in a wah pedal labeled Foxx Wah & Volume. The potentiometer has been replaced so I'm unable to date it but almost certainly 1970s. I believe the same manufacturer issued their wah pedals under various brands including Foxx, Regal, Heil, Footsystem, etc.

 

[AnalogKid]

Single-sided and only 25 components. If you know which ends are the input and output, this is not a difficult schematic to reverse. To start, print the bottom side image mirror-image, and start marking up a blown-up image of the top side with traces. To keep the board design single-sided, there are lot of long traces looping around things. Step 2 is to redraw the traces with more straight-line connections to eliminate all of that looping clutter. Now you have something you can transfer to paper. All of that is less than 1 hour.

What are the markings on the transistors?

ak

 

[Harald Kapp]

this thread is over 1 year old

 

[AnalogKid]

Yeah, but I didn't see an actual answer in the thread, and he's still around.

ak