DOD 250 chip use

philbinator1 · March 23, 2010, 10:06:40 AM

hey guys, i've decided my next project is gonna be a DOD 250, seems like a staple od around here. The regular IC (according to the vero i'm gonna work from) is a LM741. the only thing i have close is a UA741CP...will that work? If not i have other ic's in a jewel box from Small Bear...any recommendations?

cheers and thanks!

phil

StereoKills · March 23, 2010, 10:21:21 AM

Yup, it's a 741. It is exactly what the doctor ordered for a 250.

philbinator1 · March 23, 2010, 10:22:33 AM

Quote from: StereoKills on March 23, 2010, 10:21:21 AM
Yup, it's a 741. It is exactly what the doctor ordered for a 250.

awesome, thanks. i start tomorrow, wish me luck, and prepare yourself for many annoying noob questions

StereoKills · March 23, 2010, 10:31:04 AM

Good luck!

Renegadrian · March 23, 2010, 10:38:22 AM

I'd like (if I may) to suggest you a switch for the diodes. I just LOVE to switch from regular Si to LEDs.

philbinator1 · March 23, 2010, 10:41:54 AM

Quote from: Renegadrian on March 23, 2010, 10:38:22 AM
I'd like (if I may) to suggest you a switch for the diodes. I just LOVE to switch from regular Si to LEDs.

Oh yeah? you mean, just use regular 3mm leds instead of the diodes?

philbinator1 · March 23, 2010, 10:42:52 AM

another thing guys, do you know if this is the grey version or the yellow? i hear the yellow was pretty crap?

EDIT: I hope i'm allowed to post this, it doesn't say not to. I got it off diy layout creator.

Renegadrian · March 23, 2010, 10:46:47 AM

This should be the yellow, I built 3 gray and they don't spot that 25pF.
Usually yhe 250 has only 2 diodes, so symmetic clipping - that is unusual!

I built mine with 2 1n4148 on one side of the switch and 5mm ordinary red LEDs at the other side.
With the first setting you got great distortion and "tight, compressed" sound.
With the second setting you loose some distortion but the sound is more "open", more clarity, less "compression".
As I love both settings, here goes the switch.

philbinator1 · March 23, 2010, 10:59:54 AM

Hmm bugger ill have to find a vero for the grey, i wanna do that one. Adriano, do you know what the 250 is like compared to the mxr dist +? I've read they are really similar, but which would you say is better? Or too similar to call?

Renegadrian · March 23, 2010, 11:07:59 AM

Hey you wanna build the Grey on vero?! Here it is!
http://www.aronnelson.com/gallery/main.php/v/Renegadrian/250+grey.gif.html

As I am a Malmsteen guy, I just had to build one...And that's a winner for me...
D+, yeah, that's very similar, but never built one so far...

Electron Tornado · March 23, 2010, 01:26:24 PM

Quote from: philbinator1 on March 23, 2010, 10:59:54 AM
Hmm bugger ill have to find a vero for the grey, i wanna do that one. Adriano, do you know what the 250 is like compared to the mxr dist +? I've read they are really similar, but which would you say is better? Or too similar to call?

They are basically the same circuit with a few component values that are different. To me, they sound basically the same. You can find the schematics for both of them online. See which components are different and try different values yourself. Also, try a number of different diode combinations and see what you like.

I'm not sure if there's a video comparing the DOD 250 to the MXR Distortion +, but here is a link to a video of a side by side comparison between the grey and yellow DOD pedals:

http://www.youtube.com/watch?v=lc8wjq2TjhA

zombiwoof · March 23, 2010, 05:47:59 PM

I've got a related question, I'm going to mod my DOD YJM 308 pedal, the Yngvie version of the 250, with the 1458 chip (replaces the 4558 in there, supposedly closer to the old 741 in sound). I found 1458's by two manufacturers, one is a MC1458CN (made by ST devices), the other is the LM1458N, made by Fairchild. Does it matter which one I get? I wonder if there is going to be any difference in the sound between these two chips.

Thanks for any info,
Al

Renegadrian · March 23, 2010, 07:41:41 PM

I have no idea...They should have slight differences maybe...

Mark Hammer · March 23, 2010, 08:18:26 PM

Quote from: zombiwoof on March 23, 2010, 05:47:59 PM
I found 1458's by two manufacturers, one is a MC1458CN (made by ST devices), the other is the LM1458N, made by Fairchild. Does it matter which one I get? I wonder if there is going to be any difference in the sound between these two chips.

The differences, if any exist, between these two chips will be like a grain of sugar in a bathtub of water when compared to the likely differences between any given pair of diodes, or the caps you use.

philbinator1 · March 24, 2010, 12:22:03 AM

Quote from: Renegadrian on March 23, 2010, 11:07:59 AM
Hey you wanna build the Grey on vero?! Here it is!
http://www.aronnelson.com/gallery/main.php/v/Renegadrian/250+grey.gif.html

As I am a Malmsteen guy, I just had to build one...And that's a winner for me...
D+, yeah, that's very similar, but never built one so far...

Thanks man! I'll have a look at both and start when i get home from band practice.

ciao

oldrocker · March 24, 2010, 07:26:55 AM

I have built 3 of the pedals. The OD-250, D+ and the 308. Personally I think the 250 and D+ sound quite different. IMHO the 250 is a lighter overdrive and the D+ a higher distortion sound. The 308 sounds more similar to a D+ to me. I would say if you want more hard rock sound go with D+ or 308. If you play blues or country or light rock build a 250. I haven't built the grey 250 version so maybe it's a higher distortion circuit. That's my opinion. But hey why not bread board and try all of them?

philbinator1 · March 24, 2010, 08:16:24 AM

Quote from: oldrocker on March 24, 2010, 07:26:55 AM
I have built 3 of the pedals. The OD-250, D+ and the 308. Personally I think the 250 and D+ sound quite different. IMHO the 250 is a lighter overdrive and the D+ a higher distortion sound. The 308 sounds more similar to a D+ to me. I would say if you want more hard rock sound go with D+ or 308. If you play blues or country or light rock build a 250. I haven't built the grey 250 version so maybe it's a higher distortion circuit. That's my opinion. But hey why not bread board and try all of them?

Thanks for that input oldrocker (sorry can't remember your first name?)! with that in mind i think i'll go for the Distortion +, i already have a tubescreamer anyway so might as well do the next progressively heavy sound. although i'll probably build Renegadrians in the future cos of the cool diode switch feature.

cheers!

oldrocker · March 24, 2010, 01:36:02 PM

Keep in mind (fuzzcentral) has the schem for the DOD YJM308. Cool hard distortion too. It uses half of a dual op amp and is super similar to the D+ and 250 layout. Just thought I'd mention it. Good luck on you pedal.

zombiwoof · March 24, 2010, 01:38:29 PM

Quote from: oldrocker on March 24, 2010, 01:36:02 PM
Keep in mind (fuzzcentral) has the schem for the DOD YJM308. Cool hard distortion too. It uses half of a dual op amp and is super similar to the D+ and 250 layout. Just thought I'd mention it. Good luck on you pedal.

The new (RI) 250 uses the same dual opamp (4558). The 308 just has a couple of different values in it to make it closer to the old 250's in sound. Either can be easily modded to old 250 specs.

Al

deadastronaut · March 24, 2010, 01:45:06 PM

Quote from: Renegadrian on March 23, 2010, 11:07:59 AM
Hey you wanna build the Grey on vero?! Here it is!
http://www.aronnelson.com/gallery/main.php/v/Renegadrian/250+grey.gif.html

As I am a Malmsteen guy, I just had to build one...And that's a winner for me...
D+, yeah, that's very similar, but never built one so far...

how do you get a malmsteen sound out of a dod 250....

just curious!...

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DOD 250 chip use