freestompboxes.org

http://www.yngwiemalmsteen.com/yngwie/f ... cessories/

You suppose it's a red OD250?

https://www.fender.com/accessories/peda ... 07000.html

$99.99

Why didn't Fender make the scale go to 11?

Every now and then it's great to find you are dead wrong about something.

Bought one of these in late spring on an impulse. Tried it out of course and it sounded and felt quite close to my DOD Malmsteen signature. Not quite like it, but sorta close. Tried to open it up back then, but didn't have suitable allen key (what's with you people using imperial keys!) to take the knobs off. So it got left behind and i almost forgot all about it. Today i suddenly recalled that i had ordered imperial keys long ago and took the pedal apart. Didn't get to do any tracing, but snapped a few shots and wrote the BOM down. And no. It is not an OD250.

So. This is what i have for now...

C1 - 102
C2 - 4µ7/50V
C3 - 474
C4 - 102
C5 - 10µ/50V
C6 - 221
C7 - 10p
C8 - 4µ7/50V
C9 - 103
C10 - 104
C11 - 104
C12 - 4µ7/50V
C13 - 2µ2/50V
C14 - 102
C15 - 4µ7/50V
C16 - 391
C17 - 104
C18 - 102
C19 - 104

R1 - 10K
R2 - 470K
R3 - 10K
R4 - 10M
R5 - 110K
R6 - 100R
R7 - 22K
R8 - 22K
R9 - 470K
R10 - 1R
R11 - 200K
R12 - 100K
R13 - 1K2
R14 - 200K
R15 - 470R
R16 - 100R
R17 - 10K
R18 - 22K

U1 - Texas Instruments RC4558P
Q1 - 2N7000
Q3 - 2N7000
D1 - 1N4148 (or something very close)
D2- 1N4148 (or something very close)
D4 - 1N4148 (or something very close)

Errors are possible.

Thanks for your post and the great pics, Mirosol. Unfortunately, we can't see the wiring and resistors hidden behind the potentiometers... Can anyone help?

It's a variation of the DOD250 or DOD308:


The second opamp could be used to add a little volume at the end. The mosfets are for switching and maybe polarity protection

What looks interesting to me is the reverse audio-taper pot for the gain control. DOD did that a lot for their later distortion boxes, and you'll see the last little bit at the top end of the rotation was marked 'BOOST'. Usually here it gets over the top, and noisy. I've replaced them with a lower value linear taper pot, and been a lot happier with my DOD. Yes, less gain, but less over the top.

As far as I know, every DOD 250, MXR Distortion+ and Micro Amp came with a C500k gain pot.

I'm not sure that's right. My handful of vintage and reissue Distortion+ boxes have A1Meg Gain controls. The Microamp yes, but DOD was known for RA controls from my experience. The last 280 compressor I restored had a C500K 'Sensitivity' control, and they're difficult to locate. Not impossible, but difficult. In that part of the circuit, it doesn't have that huge jump at the end and compress over the top, but as a Gain control in all my 'later' DOD dirt boxes, they just have that huge jump right at about 4:00, go over the top, and the pedal gets noisy. Now I haven't played a YJM box, but I'd suspect the same, and that's weird to me. We're all so particular these days about our pedals, and putting one out that has those 'quirks' seems like a bad idea. I could be 100% wrong, but that's just a first impression from the photo.

Thanks for your post and the great pics, Mirosol. Unfortunately, we can't see the wiring and resistors hidden behind the potentiometers... Can anyone help?

I just got onenof these too, miro, what do you think? I like it. I like the responseni get, i havent done the yngwie setting yet “all cranked into a dirty marshall” but i like the top end response. I like alot of bite hence why i love the bb and kot soo much. I think its especially great for retaining clarity and treble in the neck humbuggy position. Wish i had known about these in my gigging days.

Could it be some kind of Voodoo Lab OD, which essentially is a DOD250 + additionnal gain stage.

[quote=jefjef post_id=256710 time=1452286813 user_id=76629]
Thanks for your post and the great pics, Mirosol. Unfortunately, we can't see the wiring and resistors hidden behind the potentiometers... Can anyone help?
[/quote now I got pics closer of resistors below the pots. I routed the trails from bottom with sprint layout. with your help I can route the top too.
cheers
sorry about the number of picks. these was taken by a friend in the other side of the country

Great post thanks to mirosol!
Has anyone done any further work on this? I tried to trace the circuit using the photos posted here to learn how it's done and it's certainly not DOD250 or DOD YJM308 or the voodoo drive!
Does anyone know if it has been done by someone already? Maybe we can collaborate and be the firsts!

Guardead wrote: ↑14 Jan 2022, 18:33 Great post thanks to mirosol!
Has anyone done any further work on this? I tried to trace the circuit using the photos posted here to learn how it's done and it's certainly not DOD250 or DOD YJM308 or the voodoo drive!
Does anyone know if it has been done by someone already? Maybe we can collaborate and be the firsts!

Have you figured it out yet? I'm also trying to build this pedal. We could collaborate if you haven't done it yet but still interested.

WOW
it was originally posted in 2015 and still no schematic ?????
This surely must be a record for the longest procrastinated trace on fsb
lol
bajaman

Good day to all participants! I decided to assemble this Malmsteen Fender Overdrive pedal. But there were questions with switching Q1 and Q3, and in general in the wire area, as well as in the C 2, C 19, C 5, C 3 area on the front side of the board. This is mine you can say the first experience. I assembled from those components that I found in a landfill and sale and bought on the radio market. Help, please, someone!

I don't see a schematic in this thread, can you post one please.

I don’t have a diagram. I was guided by the photos in this forum thread.

deltafred wrote: ↑17 Nov 2022, 09:14 I don't see a schematic in this thread, can you post one please.

Particularly interesting is the connection of 1 legs (S) Q1 and Q3 of 2n7000 transistors in the area of ​​​​the dpdt switch and 1 tracks of Q1 going to the input of the guitar (it is not visible in the photo behind the input and output jacks as well as the course of the track 2 legs of the effect level-output potentiometer, further following this track (I assumed its direct input to the lower middle output of dpdt), as well as the connection of the track from the 50 kΩ potentiometer (its second and third legs) going to the ground of the input jack, and then the jumper from the back of the board to the external, front, where behind the input jack again nothing is clear.