I did something but I don't know what.

[waltdogg]

So I'm an absolute fucking idiot and attempted to mod my OCD V1.4 some time ago. Following the instructions which read "The mod is the 1N34A diode located just above C1 and to the right of Q3 on the left edge of the board" I assumed they meant the diode at D2 because I'm an idiot who can't tell left from right and the idiot that wrote the mod up didn't just say R3. So I cut out diode at D2 seeing as it was above C1 and on the left edge of the board, just not right of Q3... So I soldered a jumper and called it a day. As far as I remember I don't think I heard a difference A/Bing the modded pedal with a stock one. Definitely didn't hear the fabled gain drop and fizz reduction, but maybe after the mod my OCD was darker/warmer than a stock one (V1.4 that is). It's been quite a while. So if anyone knows what the fuck the diode at D2 does in a V1.4 OCD please tell me before I go in and cut out the right one at R3. And while we're on the subject if there's anything else to cut or to jumper let me know. I'd be happy to tear this pedal a new one.

Here's a picture that points out the diode I was supposed cut out. The one I cut out is the one covered in hot glue/epoxy.

[crochambeau]

I have no idea if the schematic is correct, nor have I poked around in an OCD.



Based on the provided information, there are only two non LED diodes, and you claim to have jumpered D2 (upper right corner circuit) which sets bias for a transistor that looks to me to be there for the sole purpose of eliminating LED noise. So if your unit now pops when switched or has the faintest veil of grainy harshness it might be worth undoing the bridge, otherwise I wouldn't worry about it.

Don't be hard on yourself regarding left & right, those are relative directions based on the assumption you are looking at the circuit from the same fucking chair as whoever wrote it up. ABSOLUTE coordinates are the key to useful information.

[Jero]

Agreed, it does appear the diode you removed is just a part of the millennium bypass used. D1, in conjunction with Q2, are providing clipping. Removing D2 will also "remove" Q1 by default. There will still be clipping within the IC and rest of the circuit, but you will remove that hard clipping to ground, which generally should provide the changes you were seeking..."fabled gain drop/fizz reduction."

[waltdogg]

Hmm. So I should just leave the jumper on D2? As for cutting out R3, the actual suggested diode, I read an account that just cutting it out and not jumpering it really opens the pedal. At this point I'm willing to do whatever. I'm gonna save up for a V3 or have my friend build me a V3 and rehouse it in my V.1.4 box. Thanks for the reassurance.

[waltdogg]

I went ahead and cut out the germanium diode, this pedal has never sounded so good. Don't really know if I even want to bother jumpering this position like the mod suggests. Guess I will to see if the LED comes back on or if I can tell the difference. And yeah, now my LED doesn't work. Dunno what's up with that.

[waltdogg]

Yeah the status LED is somehow related to the clipping diode. I jumpered R3 and and LED came back on. I did cut my jumper at D2 afterwards just to be certain any harshness that can be removed will be removed. And the result is a much more real sounding pedal than the stock circuit. Almost no difference between no diode or the diode jumpered at R3 except for the LED not working when it's cut. So what exactly did cutting these two diodes out f the circuit do to my pedal anyways?

[crochambeau]

I can see how shorting out D2 may load the power rails down (and therefore impact sonic performance) but I cannot fathom how cutting the 1N34 in D1 position would affect the LED. Perhaps the schematic I referenced earlier is incorrect and you were fucking with the right diode all along?

[waltdogg]

I originally removed and jumpered D2 thinking I was performing the mod. I don't really remember what this did to the sound at this point compared to a stock V1.4 OCD. I then cut the jumper at D2 as suggested earlier to prevent any noise/harshness. I don't know what's up with the schematic it shows R3 as a 10k resistor in the power supply? While D1 on the schematic is clearly R3 on my PCB and same for the picture.

[multi_s]

I think cutting what is D2 in the schamatic should cause the LED not to work. If you cut it out there is no current through the emitter of what is Q3 on the schematic, so nothing through the collector either.

Q1 and Q2+D1 on the schematic each clip the signal so removing D1 will remove any clipping on one half of the waveform (looks like the "positive" half wrt to "V1") so this will open up the sound and make it less distorted. Shorting D1 would intensify the clipping on the positive half since the level at which it clips is reduced (less headroom). The distortion will also become... symmetrical (and that illusion that there was actually at least 6 tubes in your pedal will disappear) (;

I think it is quite possible the schematic numbering and pcb numbering are not consistent, consider that it looks like from your photo R18 and C10 are connected. I can;t even find R18 on the schematic, and i don't see it connected to C10 on the schem anyways. It may be the right (or at least similar) circuit though. Yours also has a D3 in the lower right hand corner of the board as pictured and, as pointed out earlier, there are only 2 non LED diodes in the schematic.

[waltdogg]

Hmm. I'm pretty confused at this point. Pedals and circuit mods have never been my forte.

[multi_s]

Hmm. I'm pretty confused at this point. Pedals and circuit mods have never been my forte.

if you are happy with the result, then i would say you did just fine.

i just meant to say that the schematic is certainly not the same as your pcb, so your own experience is a better indicator than theorizing what would happen according to the schematic.

s

[waltdogg]

It works, I think.

Okay then, Thanks!