My Gray DOD 250 Overdrive Clone

[mentoneman]

making me miss my old yellow od250...

 

[Steve Mavronis]

you say you have the yellow dod 250, i have this pedal and it has been through the wars and is in bits. Im trying to put it back together, pcb is ok, having trouble with the wires, if you can take some close up photos of the wiring inside, and send them to me, it would be just great

I have some photos of the yellow reissue 250 and YJM308 which use the same circuit board that I can email to you for wiring reference. I also have collected photos of the original 80's yellow 250 as well. I'm assuming you have the newer reissue yellow 250 version?

 

[Steve Mavronis]

I still owe you pics

I have 2 original gray models, one I ripped apart to tinker with. The other is untouched and in mint condition.

Oh yeah! Hey can you carefully measure the gray PCB size from the pedal you have apart aready and give me the exact width and height of the board? I want to draw a precise graphic of the gray 250 circuit board and component positions. Good clear photos of the front and back of the PCB would help too. Email to snmavronis@gmail.com and thanks!

I have a fried pre-LED 1980 version of the MXR Distortion+ and a working tan Ross R50 Distortion pedal that I just started doing the same with now.

LOL, here's a picture of my minimalist pedal chain:

 

[andomando]

hi steve,
pics and info would be great,
my dod250 is the "old yellow version,"
look forward to seeing the pics.
thanks
andomando

 

[Steve Mavronis]

my dod250 is the "old yellow version,"
look forward to seeing the pics.

Okay I'll email you what I have on the old yellow versions in a little while. Have to do some store errands out on the road and then I'll be back.

Update - I emailed you a bunch of 80's yellow 250 gut shots a little while ago. I hope they help!

 

[Atomic Playboy]

My YJM308 was modded by Analogman first, 741 mojo mod, true bypass, green LED, then I sent it to John Evosevic for his grey DOD 250 spec upgrade and I can tell you it is the most killer pedal of it's type I have. So I have the best of both worlds I think. sold my YJM Strat though so I hardly use it at the moment.
Atomic Playboy

 

[JohnnyC]

Pedal Looks freaking Sweet!!!
the 250 was the first kit i ever got as a present from the BYOC line...and since then ive been on a DIY fueled addiction.

great design/concept and looks killer

DIY FTW!!!

 

[Steve Mavronis]

My YJM308 was modded by Analogman first, 741 mojo mod, true bypass, green LED, then I sent it to John Evosevic for his grey DOD 250 spec upgrade and I can tell you it is the most killer pedal of it's type I have.

Analogman does good work (plus the personal Yngwie connection with the YJM308) and I've also heard good things about John's work too, with him testing different part brands and everything for the truest sound. I was going to use one of them to mod my YJM308 (or do it myself) but after researching what it takes ended up deciding on just building my own gray spec DOD 250 from scratch. There is something interesting about the part to part connection ordering from the original PCB that I wanted to try and duplicate, as sort of a mojo factor to me, when designing my own custom board layout.

 

[Steve Mavronis]

my dod250 is the "old yellow version"

Here's a quick schematic I updated after verifying the parts on your 1982 yellow 250 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.

I'll get an answer for you soon so you can wire your board to the jacks and footswitch as on the original.

 

[Steve Mavronis]

Andomando,

Okay well is the offboard wiring in the schematic I made below consistant with the example 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.

Example yellow 250 gut shot:

 

[andomando]

Thank,s Steve,
Ill give it a try,and get back to you..

 

[Steve Mavronis]

You're welcome. I posted about the offboard jack wiring on several DIY stompbox forums too and discussing this to make sure I have the schematic drawn correctly to depict the wiring of the jacks and footswitch. Use that gut shot photo as a guide too and you should make your wire colors match as well if you can. Good luck and I'll update here if I get more info. I'm collecting research material on all the 250 versions so all this helps.

 

[andomando]

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.
i have a drawing of this ,but alas,,cant seem to upload image into this letter.
will post by email.

 

[Steve Mavronis]

Yeah I was wondering if I used the proper schematic symbol for that type of dc jack. I used a different boss style 2.1mm center negative pin dc jack for my clone 250. But I think in principle they work the same way. Pins 2 and 3 (both positive) are connected until the power jack is plugged in which then disconnects the battery's red wire connection. I'll compare to your style dc jack which is the same type as used on my old tan Ross Distortion.

Here is your DC jack sketch by the way:

 

[Steve Mavronis]

I decided to see how my pedal works with a Metal Can 741 op amp vs. DIP in the IC socket. I don't really notice much of a sound difference but since it is a vintage RCA 741 should I keep it in or go back to the Motorola LM741CN op amp DIP version? I don't know if I'm kinda out of 'gray spec' or not using the Metal Can 741 although RCA 741's were used around 1979 in the gray DOD 250. Here are some pictures I just took. What do you think?

I used a strain relief technique with the loops where the 4 wires attach to the PCB and I looped wires around the jacks, in the same direction so I can rotate them in the opposite direction if they needed to be removed or re-soldered. I see from my picture than I didn't loop the black battery wire around the input jack on the left, nor the red battery wire around the DC jack on the right. I think they were the first wires I put on when I was trying to figure out a neat wiring pattern to use. Maybe I thought there was enough slack with the length of the battery leads. But if I looped them around the jacks first that may act as psuedo strain relief since any pulling force would grip and distribute against the jack body.

P.S. I'm trying to get used to the idea of using a metal can 741. I couldn't really find any specs on that RCA package. Does anyone know if there is any internal circuit difference between that and the Motorola LM741CN chip that I was using? Maybe I should put it back, I don't know.