1982 Yellow DOD 250 Overdrive w/351 Wiring Help?

[Steve Mavronis]

I'm trying to help someone put back together an 1982 yellow DOD 250 (w/351 op amp) Overdrive. Can anyone help me explain to him where his wires should connect to using his sketch below?

I can't tell from reference pictures what leads are connected to with enclosed jacks and I can't see how the DC jack was wired. His 250 is using red wire for the input and blue wire for V+. The PCB wiring pad order left to right is Output-Ground-Voltage-Input. Here is a drawing and 2 pictures he sent me asking for help:





Here is a reference picture from another yellow 250 that I was trying to compare with. Note some wire colors are different than what he's using:

[Steve Mavronis]

Here's a quick schematic I updated after verifying the parts on his PCB:



I just need to work out the wiring to the jacks. Apparently the published 250 schematics don't show the wires going from the PCB to the jacks and footswitch in the exact order as they are in reality.

[Steve Mavronis]

Can anyone draw a simple schematic representing that wiring gut shot above showing how the input, output, dc jack, and footswitch are wired together? You can leave the four PCB connections for output, ground, voltage, and input hanging. I can wrap everything together later. Thanks but none of the existing 250 schematics with a regular SPDT footswitch truely represent how this pedal is actually wired point to point in its original state. I'm really confused how the jacks are wired in the photo since I can't tell for sure what is the tip and ring lugs, plus on the DC jack there is 2 red wires going to the same lug and no black wire going there so I assume it's grounded to the enclosure.

[Joe Hart]

Can anyone draw a simple schematic representing that wiring gut shot above showing how the input, output, dc jack, and footswitch are wired together? You can leave the four PCB connections for output, ground, voltage, and input hanging. I can wrap everything together later. Thanks but none of the existing 250 schematics with a regular SPDT footswitch truly represent how this pedal is actually wired point to point in its original state. I'm really confused how the jacks are wired in the photo since I can't tell for sure what is the tip and ring lugs, plus on the DC jack there is 2 red wires going to the same lug and no black wire going there so I assume it's grounded to the enclosure.

Okay, no one else is bitting, so I'll give it a try. It looks like the purple wires on the in and out go to the switch, so they must be signal wires ("tip"). So the other ones on the jacks are the "ring" wires. The purple wire from the in goes to the switch, then either goes to output (purple wire) of the circuit (green wire). Also, the drawing is incorrect in at least one way -- the wires going to the PCB are not "green, black, blue, red" but "green, black, red, blue" (according to the picture). And it may be cynical of me, but I subscribe to the theory that if there is an obvious error, there very well may be more no so obvious errors. Where did you get the info that there are two red wires going to the DC jack? I can't see that in any of the posted pictures. And if the owner told you that... well, the drawing is wrong...

Anyway, just a quick look and that's what I have for you. Hope it helps some! Or gets others to offer their know-how (because mine is admittedly limited).
-Joe Hart

[Steve Mavronis]

Also, the drawing is incorrect in at least one way -- the wires going to the PCB are not "green, black, blue, red" but "green, black, red, blue" (according to the picture). And it may be cynical of me, but I subscribe to the theory that if there is an obvious error, there very well may be more no so obvious errors. Where did you get the info that there are two red wires going to the DC jack? I can't see that in any of the posted pictures. And if the owner told you that... well, the drawing is wrong...

Thanks Joe for your insight! Yes his drawing is wrong according to what the wire colors are supposed to be and I told him that. But I'm assuming maybe his pedal was wired like he illustrated since sometimes you see pedals not adhering to wire color standards. It's hard to see the DC jack clearly in that gut shot reference photo (which is not his pedal) that I was using as a wiring guide. There are 2 red wires going to it with no black wire. Maybe there is a lug behind the one with the thick red battery wire that I guess the thin red wire from the PCB is soldered to. I'll try to use your description as a schematic guide.

This is yet another reason I don't trust 'established' pedal schematics that are not drawn by the company who produced it. For example here is an old schematic before people started adding true bypass and 3PDT switches. If you follow the wiring to the jacks, while electrically valid in its own way, does not follow how the pedal is actually wired. In the photo the blue PCB input wire goes to the input jack before hopping to the footswitch with the purple wire, etc:

[Steve Mavronis]

Okay well is the offboard wiring in the schematic I made below consistant with the 250 gut shot photo? I'm not too good at redrawing schematics so some adjustments will probably have to be done. I'm not sure of the orientation of the footswitch from physical to schematic representation.

[slacker]

That looks right to me, it will work anyway even if it doesn't exactly match the gut shot.
I don't know if you've already figured out the PCB connections but from the first drawing they are.
Green = out
Black = ground
Blue = 9 volts
Red = input

From your reference Yellow 250 photo, the switch lug on the left (the one on it's own) is the throw connected to the input. The one top right is the throw connected to the output and the one bottom right is the pole connected to the output jack tip.

[Steve Mavronis]

From your reference Yellow 250 photo, the switch lug on the left (the one on it's own) is the throw connected to the input. The one top right is the throw connected to the output and the one bottom right is the pole connected to the output jack tip.

Thanks for the footswitch info! I wasn't quite sure.

I suggested to the guy that needs the help he should go with the standard red wiring for positive voltage and blue for input to the PCB.

He emailed me this little sketch he made of the DC Jack (I don't know how accurate the description is) saying:

Steve, check out the wiring between the battery snap connection and the dc input, Ive read that the battery snap connection goes to the centre tab on the dc jack and that disconnects the battery snap when the dc plug is inserted.

[Joe Hart]

Yes his drawing is wrong according to what the wire colors are supposed to be and I told him that.

Whoops. I thought all the pictures were of his actual pedal. Sorry! 
-Joe Hart