Anyone familiar with the OCD circuit?

[HeavyXIII]

I hear it's highly similar to the D+, DOD250 and Voodoo Labs OD250 and that many people prefer these circuits to proc asymmetrical clipping for clarity and fuzziness. I recently acquired a Joyo Ultimate Drive and have been interested in this type of mod for some time, but only was able to get it open last night. I see a few different diodes in the circuit, but only 2 appear to run in parallel (D3 and D4) which are both 1n variant diodes (can't really see the rest of the designation). I wanted to clarify that these are the diodes I'd want to experiment with, and the not D1 or D2 earlier on in the circuit.



As pictured above, the red section, not the blue ones?

[D.o.S.]

Vintage Freekish Blues alert!

[Gone Fission]

The pedal uses mosfet transistors as diodes for clipping, one in series with a normal diode, usually germanium, to clip asymmetrically. My casual guess is that the clipping section is around D2.

You should search freestompboxes.org on this pedal. I think some mods and helpful info is already waiting there for you, including schematics to work from.

[HeavyXIII]

http://freestompboxes.org/viewtopic.php ... ve#p226682

I found this thread, but I'm unclear on what all the different diodes do. I get the impression that Gone Fission is pretty much on the money with the D2 clipping assertion, based on the next thread. I have a V2 circuit by the way. I also got the impression that D3/D4 were related to the 9V power supply, but I'm not certain.

http://freestompboxes.org/viewtopic.php ... ve#p227483

Will there be a substantial different in removing the diode in D2 vs removing the proper mosfet transistor? I'm trying to achieve a more loose, fuzz like sound, but I want it to retain it's touch sensitivity. After all my searching, I couldn't find anyone who's approached this pedal with the Ben Adrian style asymmetrical clipping that I'm looking to try (complete removal of half of the clipping section/diode).

I don't want to feel like I'm wasting anybody's time here... Is it a better idea to just post this on freestompboxes?

[Gone Fission]

This might fly better at ILF if moved to the DIY subforum, but FSB might get more traction overall. Some dudes here do like OCDs, don't get me wrong, but I've not seen a throng of people interested in clipping mods for them.

You currently should have mildly asymmetric clipping. Yes, you can push that out. You might want to replace the current spots with sockets so you can experiment with a bunch of options. Or just desolder or clip out one side and see if your good to call it a day. I dunno, preferences are all over the place and my symmetric/asymmetric overdrive preferences flip nearly every time of the few times I use one of the damn things.

[HeavyXIII]

Ya, I gotcha there. I went ahead and posted to FSB so we'll see how that goes. Most guys on that forum seemed more worried about getting it to match specs with a legit OCD, but I'm really hoping for a much simpler change, given that I already like it a fair amount and just wish it were fuzzier.

Socketing is a great idea, I just need to figure out a) how to do it and b) if there's enough space. I'm competent enough to solder, but not quite enough to feel comfortable just winging a mod. Thanks for the suggestions!