Fulltone OCD versions

[amz-fx]

Fulltone OCD versions and mods:

http://fulltone.com/PDfFiles/OCD%20complete%20Mods_small.pdf

Official file from Fulltone site...

regards, Jack

[Bernardduur]

Where's the goop??

[Ghandi]

sometime in september 2006 jhs wrote...

For a 100k pot for volume the tone pot should 10k and 10-33n, for a 500k pot for volume the tone pot should 100k and 33-100n.
If the tone control on the OCD (100k/100n w 100k for volume) is set to zero the tone is very dull and for me nearly useless.

learning by doing or learning by listening ah reading!?!
oh, and the recomentation for the 10k pot + 33n cap was for the 100k vol pot.

does anybody of you guys know when the seriell #9474 passed?

and by the way I don't think that the 1m gain poti will sound that good.

cheers
ghandi

[Nashtir]

I played that pedal..and let me tell you that a thousand of the od posted on this forum are 1000 times better..that one sucks

[JHS]

Now, that everyone knows that it's a slightly modded VL OD there is no reason to goop it any longer.

This third version mod was developed by a FX-modder and published in another forum a few month ago.
The same with the 500k vol mod for the 2nd version. 

I like the first version better, way more open sounding and IMHO V1 is much better for clean boosting and light crunch. The third version is a real mid humper with reduced high and bass end and IMHO not good for boosting a clean sounding guitar or for light crunch.

I don't recommend to change the vol to 1M, w the 1M it sounds more like a fuzz pedal when maxed and very compressed and furthermore the 1M makes it hard to dial in gain nuances when the gain is set low.

When the tone pot (it's a simple guitar tone control wired to the vol pot)  is closed the sound is IMHO dull and useless and a small R in series  with this pot is a good mod to prevent this effect.

JHS

[96ecss]

Now, that everyone knows that it's a slightly modded VL OD there is no reason to goop it any longer.

Hi, sorry for the noob question. Does VL OD mean Voodoo Lab Overdrive?

Dave

[smank]

Hi, sorry for the noob question. Does VL OD mean Voodoo Lab Overdrive?
Dave

Yes


Hi JHS, just two questions.
1. Looking at original mods pdf photos, it seems the clipping section is realized with 3 MOSFETs (for a classical asymmetric distortion). Is it a right supposition?
2. In the photos I see also two 1N400X type diodes, one on the left (probably for supply polarity protection), one on the rigth. Do you know the use of the right one?

[JHS]

VL=Voodoo Lab

The 2nd diode (any Si-diode like 1N914/4148/... will work) and the 3rd trannie belong to the LED-circuit.  The led is wired in series with the collector R of the trannie and the footswitch shorts the LED when the FX is in bypass mode.

JHS

[Mark Abbott]

This is quite an interesting thread, I was under the impression that the OCD was an original circuit developed by Mike Fuller.

So the OCD pedal is in fact a VooDoo labs pedal?

Are there links for the circuit diagrams etc?

Do you suppose Mike Fuller is a member here?

Yours Sincerely

Mark Abbott 

[swt]

Hey Mark!! i know you from the trainwreck and d*mble forums. I have that schem...can't remember the link i got it from...but can email it to you if you want.

[rhys]

Here's a link to the VLOD schem.

http://www.freeinfosociety.com/electronics/schemview.php?id=1208

[amz-fx]

ooops, hit the wrong button...  wrong reply thread...   

[wampcat1]

This is quite an interesting thread, I was under the impression that the OCD was an original circuit developed by Mike Fuller.

So the OCD pedal is in fact a VooDoo labs pedal?

Are there links for the circuit diagrams etc?

Do you suppose Mike Fuller is a member here?

Yours Sincerely

Mark Abbott 

Word around the grapevine says Mike does browser through here a bit.
I can't think of one fulltone pedal that has been an original design, no disrespect to Mike - he's very good at marketing!
Honestly though, 95% of the "boutique" builders (is there really such a thing anymore?) are just building modified versions of existing pedals and to be fair, there isn't much that hasn't bee tried in some shape, form, or fashion in the distortion/overdrive/fuzz arena. I mean, there's only so many ways to skin a cat.

bw

[The Tone God]

I can't think of one fulltone pedal that has been an original design, no disrespect to Mike - he's very good at marketing!

Agreed but with all the bad things you can say about Mike and his product designs the one thing he still does that other builder still don't do very well is making the pedal tough. Tour worthy. I give him credit for that alone.

Andrew

[MKB]

Now, that everyone knows that it's a slightly modded VL OD there is no reason to goop it any longer.

Not doubting that it is a tweaked VLOD, but if you count the caps and resistors seen in the ungooped pictures, there are a few more parts in the OCD than in the VLOD, even if you count the HP/LP switch and associated components, and the tone control and cap.  Also I built a VLOD and it sounds nothing at all like the OCD; the clarity of the OCD is staggering.  I strongly suspect the OCD has some more stuff going on in there.  Also there do not seem to be any series diodes with the MOSFET clippers.  It sure would be interesting to see a schematic though...

[MartyMart]

Here's my VooDooLabs OD vero layout from early 2005 from Justins schem:
http://aronnelson.com/gallery/Martys-layouts-and-photos/VooDoo_Labs_OD?full=1

Gain should be a 500k ( all I had ten were 470's )
It's a cracking little OD circuit,
Mod away !!

Marty.

[WGTP]

I would like to know which Mosfets are being used.  I have tried almost a dozen and they all sound different.  Different clipping thresholds, capacitance, transconductance, etc.

I don't know, but he may be using the second method posted here at AMZ.  It works well with a low threshold Mosfet, but the std. BS170/2N7000 clipping threshold is a little high.  The IRF510 is even higher, potentially maxing out the op amp first???.  http://www.muzique.com/lab/zenmos.htm   

[PaulC]

I don't know the OCD circuit, but it seems a little bit different.  From the mod page if changing the gain pot to 1M gives more gain then that tells me that the pot is in the feedback loop, and not hanging off of the inv input.  If it was set up like the VL then a 1M pot wouldn't increase gain - it would lower it at the lowest settings.  Just a guess.

Later, PaulC

[MKB]

Here's my VooDooLabs OD vero layout from early 2005 from Justins schem:
http://aronnelson.com/gallery/Martys-layouts-and-photos/VooDoo_Labs_OD?full=1

Gain should be a 500k ( all I had ten were 470's )
It's a cracking little OD circuit,
Mod away !!

Marty.

Thanks for the layout, that's the one I built.  I made some of the mods listed here and elsewhere to try and get the clarity of the OCD, no luck.  Also, that would make sense what WGTP posted, the second clipper in the AMZ article; nice and simple and does the job with no series diodes.  The main problem to my ears with the VLOD is the lows seem artificially clipped along with the highs (not too fond of that sound).  Maybe the OCD has some sort of frequency dependant clipping, maybe clipping the highs while leaving the lows relatively unclipped.  I was going to try adding an additional 4.5v divider for the clipper voltage reference and using a smaller bypass cap to roll off the clipping at lower frequencies. 

[Torchy]

Then again, maybe the OCD simply isnt a VLOD knock-off 

So far we have had people insisting that its a TS, a Dist+, a Sparkledrive, a VLOD etc etc etc with absolutely nothing to confirm the claims. Until someone I trust comes up wth either ungooped pics of comp&trace, and a schematic, Im not holding my breath. I have no doubt it is a modded <whatever>, but as I didnt like the one I tried out I can wait.