Fulltone - OCD  [traced]

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Re: Fulltone - OCD

Postby POTL » 01 Sep 2017, 02:06

bugg wrote:Sorry man, haven't forgotten about you! Had to deal with some car repairs this week so been busy.

The trace is done, PCB is drawn, I just need to clean up the schematic and export to an image then I'll post it.


OK
Thank you bro
In fact, I do not need a fee. I'm interested in the circuits themselves.
1) I like to breed boards myself
2) The scheme is interesting from the sports interest, I do not plan to collect a clone for myself or for sale, I'm just curious
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Re: Fulltone - OCD

Postby bugg » 02 Sep 2017, 23:07

Schematic.png


Here ya go, I'll upload a pinout for the 3PDT shortly. I have PCBs ready to go for this if anyone wants em.

I'm aware that Q5 appears to be upside down, I reconfirmed this multiple times, it is correct. Since these are 2N5457 the Drain/Source is interchangeable.
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Re: Fulltone - OCD

Postby POTL » 03 Sep 2017, 00:47

bugg wrote:
Schematic.png


Here ya go, I'll upload a pinout for the 3PDT shortly. I have PCBs ready to go for this if anyone wants em.

I'm aware that Q5 appears to be upside down, I reconfirmed this multiple times, it is correct. Since these are 2N5457 the Drain/Source is interchangeable.


thank you very much
in the description it was said that there will be buffers, and he added boosters lol
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Re: Fulltone - OCD

Postby boukman » 05 Sep 2017, 13:53

Hi guys!
So is that buffer worth the effort?I already have an OCD clone.All that talk about Class A buffers at the product description..I mean is it really much better than a simple fet buffer in the dynamics department?
Can someone post the schematic of only the buffers section,or a tagboard?
Thanks!!!
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Re: Fulltone - OCD

Postby Blend » 05 Sep 2017, 14:28

This new version is a maquillage operation. When the sales are jammed, the product was to be redone, the stated goal was to retire the fulldrive with the improved ocd and strange case pops up buffers like fulldrive, morning glory, ts etc etc and takes a bit here and there, like the snake that continues to bite its tail. An input Fetzer Valve, the disappearing germanium diode, and the 1k resistance on the tone as on the od Glove electro harmonix clone or other mods experienced on this forum. I bought a Ocd to resell it after cloning it and although it was not the best pedal in the world it sounded good, I will apply these novelties to the circuit and see if it's worth it.

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Re: Fulltone - OCD

Postby Groovenut » 05 Sep 2017, 15:41

POTL wrote:
bugg wrote:
Schematic.png


Here ya go, I'll upload a pinout for the 3PDT shortly. I have PCBs ready to go for this if anyone wants em.

I'm aware that Q5 appears to be upside down, I reconfirmed this multiple times, it is correct. Since these are 2N5457 the Drain/Source is interchangeable.


thank you very much
in the description it was said that there will be buffers, and he added boosters lol

Yeah, those aren't necessarily buffers and I would hardly call them boosters either. Maybe an inverting amplifier that provides unity ( 0.37dB of gain). I suppose you could call them impedance converters. I agree with the smoke and mirrors assessment so marketing can say it's something new. I doubt most could hear (or measure) a difference from the original at normal guitar levels. Of course if you hit the input with anything over the pinch off voltage of Q5 (Q6), you'll get asymmetric clipping from both Q5 and Q6.

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Re: Fulltone - OCD

Postby bajaman » 17 Sep 2017, 06:20

I had some boards made and built one to satisfy my curiosity and it sounds good - I think the enhanced bypass buffers are a nice touch - I will most likely leave the small switch in the enhanced position :wink:
PM me if you want to purchase a spare board :wink:
cheers
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Re: Fulltone - OCD

Postby Blend » 19 Sep 2017, 10:47

I agree, it now also works in front of the gain pedals or a high gain channel and the output buffer keeps a neutral sound in combination with the chain pedals. It has a low gain sound like a tube blow with the increase in average frequencies compared to previous OCD versions while distortion loses the previous bite. I would not remove the smooth germanium diode.
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Re: Fulltone - OCD

Postby 287m » 19 Sep 2017, 14:39

so its just a OCD plus buffer? hahaha
i just covered some year ago when OCD going to Carbon Delay, make vomit.
just add buffer i found in cazilt oldcraft blog, smile again. hahaha
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Re: Fulltone - OCD

Postby ggbb » 01 Apr 2018, 23:00

Is that correct - the new version has no input cap going into Q5?
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Re: Fulltone - OCD

Postby Ichabod_Crane » 04 Apr 2018, 15:55

I saw this document linked, more than one time: http://www.fulltone.com/PDfFiles/OCD%20 ... _small.pdf But there's no anymore.
May someone link it again, please? :thumbsup
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Re: Fulltone - OCD

Postby ggbb » 05 Apr 2018, 00:01

Ichabod_Crane wrote:I saw this document linked, more than one time: http://www.fulltone.com/PDfFiles/OCD%20 ... _small.pdf But there's no anymore.
May someone link it again, please? :thumbsup



That document is old and out of date anyway. It only covers up to "version 3" and all of the information is documented elsewhere on the web. But for those who want it: https://web.archive.org/web/20081209114 ... _small.pdf.

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Re: Fulltone - OCD

Postby Ichabod_Crane » 05 Apr 2018, 10:01

Thank you.
Indeed it was old, further I found it somewhere else but I didn't know that it was the same I had. :oops:

8)
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Re: Fulltone - OCD

Postby Ichabod_Crane » 07 Apr 2018, 11:36

Excuse me, I didn't really get the OCD V2.0 schematic.
I identified the original OCD section, it just includes some mods and a kind of output stage Tube Screamer type. It's useful to get the OCD more friendly with other pedals, especially those buffered. Right?

There's a switch, and you can choose EB if want to use the buffer when the pedal is engaged or not engaged, or you can choose TB if you want omit the buffer and make the pedal true bypass as the older version.

I can't understand, in the schematic above, the route and the connection of the signal through the first switch, that two buffers stage and the input of the OCD. :scratch:

Thanks!
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Re: Fulltone - OCD

Postby bucksears » 23 Apr 2018, 15:55

A couple of questions, since I've never really been into OCDs until recently.

1) Heard a demo of the 1.6 or 1.7 version last night (comparing it to a DLS III) and was wondering if there are schems for those anywhere. I've only seen info for v1.0 thru 1.4.
2) Is there an audio comparison/description of the different versions? I'm looking for whichever one(s) have the most mids.

Thanks!
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Re: Fulltone - OCD

Postby Ichabod_Crane » 24 Apr 2018, 09:33

Hello.
I am in a full immersion of the Fulltone OCD (and surroundings) schematic. :D
I guess there's a bit of confusion about the different release of the OCD. The people know the several versions called V1, V2, V3 e V4. I want to exclude the very last release 2.0: a bit different.
The changes are the tone cap and the three pots, and of course the germanium diode. The V4 should be the 1.4, that should be very similar to the 1.6 and 1.7 versions.

In my opinion, folllowing all the info I found in the web, the trackers are ignored the power supply, where we can find a diode instead of a 100R resistor, which limit the voltage, plus another diode across the ground. And, probably, a 47uF 0r 100uF cap filter, where about this, I found a comment by Mike Fuller by Fulltone.
And even a bit detail maybe is "missed", Indeed I suspect we could find in the 1.7 version of the OCD not a 500k Volume pot as we can see in the known schematic of the V4. Some images of the 1.7 PCB version shows, after the volume pot changed from 100k to 500k in the V2, the pot is back again to the 100k, initially linear, and only later log.

There's another suspect cap changed, a cap lowered in the feedback loop of the opamp to cut the bass. I read it around, but I didn't see in any schematic.
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