Original DOD 250 Grey Spec layout,and layouts with mods and transfer images

[Steve Mavronis]

This might be semi-off topic so ignore if it is. I was wondering if there was a listing of what guitarists over the years used or are using a DOD 250, YJM308, or even someones's 250 clone? The only ones I know about for sure (besides us amateurs) is Yngwie Malmsteen (gray 250 and YJM308), Joe Stump (gray/yellow 250's and modded YJM308), and his protege Dean Cascione uses a modded YJM308 and a 250 clone from FX Doctor. Please add to this list if appropriate. Even classic songs that were recorded using a 250 would be cool to know about just to go back and hear the sounds.

[Brymus]

nice Steve and Adriano
It looks like the only difference between the YJM and the 250 is the taming or anti oscillation cap in the FBL of the 741.
The only difference between the the MXR distortion +  and the DOD 250 seem to be minor value changes.

Adriano which pin does the gain lug 1 go to on your YJM vero layout ?

And I should have includued a 10n to ground at the input of the super modded 250 I posted to cut down on hiss introduced at the input.
And I should have added the option of having the small value cap in the FBL of the 741 too.
There should be room to add those by just drilling some extra holes in the existing layout,
But looking at it again I also see where I could have made the layout even better and more compact.
I may do another smaller version to use 16 mm pots,and the other added mods later on.

AnalogMan says the extra 25pf cap is used in the 308 because they used a 4558 in the pedal (actually only half of the dual 4558 IC), which has a wider frequency range than the original 741 IC.  The added cap attempts to make the 4558 sound more like the 741 circuit, and isn't needed if you are using a 741 in there.  One of his mods uses a 1458 instead of the 4558, which according to him is actually a dual version of the 741 chip, and sounds more like it in the circuit (and also doesn't need the 25pf cap).  He says the 308 does sound a little noisier with the 1458 in place of the 4558, but closer in sound to the 741.

Maybe you are already aware of this, but you mentioned having the option of using the 25pf cap with the 741, which shouldn't be necessary.

Al

Yeah your right Al,I was overlooking the use of different op amps,also
I was thinking in terms of reducing the hiss in the upper end of the frequency range,but that would detract from the "sound" of the 741 and it would also probably take something closer to a 50-100p cap to do that.(some breadboarding would be needed to say for sure)
nice catch on that thanks.

@Steve, No I think those YJM layouts are good here  ,so is the list of artist who use the pedals,even better a list of albums and tracks to give an idea of the sound in the right hands with the right amps.
I also think if you still have them ? Pics of the outside and inside of the different models in chronological order would be a really cool addition to this thread.

[Steve Mavronis]

@Steve, No I think those YJM layouts are good here   ,so is the list of artist who use the pedals,even better a list of albums and tracks to give an idea of the sound in the right hands with the right amps. I also think if you still have them ? Pics of the outside and inside of the different models in chronological order would be a really cool addition to this thread.

The YJM layouts as far as the PCB goes is the same as used on the yellow reissue pedal except they use different part values. Yeah I'm glad you also want to know the tracks the 250 was recorded on. Probably more classic songs than we realize now. For pictures I have folders on my hard drive were I've separated 250 pedals by year. Now some of them are based on what the owner said they were and what the CTS pot date codes say about when they were made before being installed in the unit. Let me organize a representation of them throughout the years and I'll post them with inside and outside shots. I've also noticed over the years the DOD logo changes position from left side to right side and back, which also sometimes helps when dating them.

[Renegadrian]

@zombiwoof

If memory still serves well, the use of a 1458 in a 308 instead of the 4558 is easy because they share the same pinout, while 741 has a different pinout, so it's not a direct replacement...

[Steve Mavronis]

^^^ Correct.

[zombiwoof]

@zombiwoof

If memory still serves well, the use of a 1458 in a 308 instead of the 4558 is easy because they share the same pinout, while 741 has a different pinout, so it's not a direct replacement...

Yes, I'm aware of that, Analog Man also does a full mod to gray spec of the reissues that uses a 741 chip, but it necessitates rerouting the pins because of the difference.  The 1458 mod he does is a "close but no cigar" mod that gets you into the ballpark of the original, but is easier because as you say the pinout of the 1458 is the same as the 4558.  I'm going to go the easier route and use the 1458, remove the 22pf cap, and change the input cap to a .01uf and see how it sounds.  I don't think there is any more to it, but I'll compare the components to the gray 250 component list and see if anything else is out of whack.

Of course, this is on a long list of projects I'm aiming to do in the near future when I can get to them!

Al

[Steve Mavronis]

Hey all. Just a minor gripe I hope. I have a problem at that "other" forum. If JOHNO (who also is a member here) is going to take my PCB transfer graphics from "this forum" and repost it on the other "Free.........." forum with a sarcastic line like this in a lame attempt to mock me:

Is this the PCB layout your talkin about? Wow that's really kind of you  

Should I just yank all my stuff and not contribute anything? I'm trying to be friendly and exclusively posting my transfer graphics here before releasing elsewhere. That's why I want them all in this gallery first as part of the DIY Stompboxes collection. This forum has helped me more than any other during my project. Eventually it will be released anywhere else but at my doing. The DOD pedal isn't my property at all but my artwork and graphics are mine and I should be the only one authorizing who gets a hold of them first and feel the people here get first try at it if they want to make one. If you want to post my graphics someplace else ask my permission which is proper to do. If not then maybe they shouldn't throw stones by instigating matters making it get ugly again. I hope not. This is a good neutral thread that Brymus started about a great classic pedal and all variations including clone layouts so pray some will not ruin the mood here, 'nough said.

[Steve Mavronis]

a full mod to gray spec of the reissues that uses a 741 chip, but it necessitates rerouting the pins because of the difference.

The YJM308 layout graphics I posted on the first page shows how to do this. It isn't that hard but the 1458 being a dual 741 shouldn't be too off spec if you don't want to cut the traces.

[JOHNO]

"Please step back, there is nothing to see here. Thank you.

[Brymus]

Could we please keep this thread on track ? PLEASE ,this thread is for those who wish to build a 250 type pedal and need help in the form of layouts ,ect,and for documenting the changes and revisions in design of this circuit.
Steve has every right to decide what to do with his artwork. So please no further posting about that...

[Steve Mavronis]

Hey Bryan if you like I'll make a better version of the YJM308 PCB layout component diagram along with the Yellow re-issue now that my ExpressPCB skills are better than when I was first learning the program. Could someone post the part value differences between the YJM308 and Yellow re-issue? They both use the same identical PCB so it would be super easy to make the layouts for each one. Thanks.

[Brymus]

Hey Steve no need to ask me,please donate whatever you feel appropriate for the thread.
I was looking at the Voodoo Lab Overdrive at Gausmarkov http://gaussmarkov.net/wordpress/circuits/voodoo-lab-overdrive/
and I think that we could even include that in this thread due to the clipping diode arrangment,
Opinions ?

[Brymus]

Gausmarkov also did the DOD 250 and still has the Eagle files up offered to use and modify.
http://gaussmarkov.net/wordpress/circuits/overdrive-250/
I really like what he has done for the DIY scene I built my Dr Boogie using his layout and PCB transfer and its now my favorite heavy OD pedal.
Anyway here is his 250

I think I will search the gallery and link all the other layouts too,make this the ultimate 250 thread for comparing layouts.
I would really like to see that pictography of the 250 and YJM you were talking about doing Steve...
Hows that coming along ?
You are probably the forum expert /fanatic on the DOD 250 history 
Any progress progress with it ?

[Steve Mavronis]

Thanks for reminding me about the 250 photo history. It's too late tonight but I'll post a set of photos tomorrow after work. Some are subject to some guesswork without at least pot date codes to go by but we'll start with what we have and make corrections as we go based on other's input and any new discoveries.

[Brymus]

Here is an interesting one I just found based on the Gausmarkov version,it would be easy to make any version with the layout though.

[Steve Mavronis]

Here are pictures I have. I included the outside because I found it interesting that the DOD logo changed positions. I remember throwing these into folders based on best guess at the time or the pedal owner's description. I'll split these across several posts.

1976 Gray 250 -



1978 Gray 250 -



1979 Gray 250 -



The large diode is not original on the PCB above.



The RCA 741 was only supposed to be used in the DOD 250 in 1979. Here you see versions with and without the extra 100 ohm resistor.




1980 Gray 250 -

[Steve Mavronis]

Here's something that I've been curious about with the gray 250. First look at this partial schematic excerpt showing the op amp output going to the diode clipping section:



Note that the 10K resistor R8 and 4.7uF capacitor C5 order is reversed from what other people's standard 250 schematics show. I only have it that way because it reflects the actual parts order on the gray PCB. Now another thing that goes on with part to part order on the PCB is C5 actually connects here to the diode clipping section:



I think (my father tells me) that electrically it's the same thing both ways. But could it make any difference maybe with a slight signal time lag or anything? Probably not but I was always curious about this. Here is my illustration representing the gray PCB layout parts pattern for reference:

[Brymus]

Thats a cool run down. Thanks
Do you have any pics of the YJM and Distortion + ?
Also what other colors and graphics have been available through the years ?
Seems I have seen a yellow 250 before, but didnt pay much attention to it.

I used to think the 10K resistor came first to act as a load for the op amp,but now I really dont think the order matters much when its in series.

[Steve Mavronis]

Bryan, here's another pair of outside/inside photos downloaded from ebay showing probably a 1979-1980 era gray DOD 250 with a UA741 IC and the extra 100 ohm resistor:



These seller descriptions are so generic. I wish they would take the time to post the pot date codes for authenticity.

[Renegadrian]

Do you have any pics of the YJM and Distortion + ?

You want some pics of the 308?!