Fulltone - OCD  [traced]

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Greg
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Post by Greg »

kungpow wrote:Yay! :horsey:

Thanks for the responses. Got it to work; sounds good, not quite as much gain as I would've expected when dimed. A few questions remain, however:
useme2305 wrote:don't forget to ground lug one of the vol and tone pots.
kungpow wrote: 1)I wired them together. Is that grounded?
They should be connected to the bottom track on the layout as shown.. doesn't matter whether they're together or not as long as they're both soldered to that track.
kungpow wrote: 2) I know the HP/LP switch is a high/low pass filter. Seems when I put it in HP, I get a noticeable Vol boost. As I interpret the layout, I have lug 3 of Vol pot to lug 1 of S1, and then the board's "S1" to lug 2 of my SPDT. Then I put a small jumper btwn lugs 2 & 3 of that. Is this normal/others experience? Am I wiring this right?
kungpow wrote: 3) Lug 3 of Drive pot is empty. Should it be grounded, or o/w attached to something?
No.. not according to the layout.
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Post by kungpow »

Thanks again!

fastfrets
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Post by fastfrets »

Hi all,

I have built the OCD based on the vero layout above.

The sound is very distorted and when the drive is turned up at all it starts to oscillate and go mad!

Any ideas what ive done wrong?

Cheers

Mike

fastfrets
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Post by fastfrets »

No one???

Still pretty stuck.

Mike

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Post by floris »

Take a look here for debugging help:
DEBUGGING - What to do when it doesn't work
https://www.diystompboxes.com/smfforum/ ... ic=29816.0

Mihajlo
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Post by Mihajlo »

Hello (for the first time).
What a great forum!
I'm starting my OVD build today (markm layout). I have the pcb and most of the parts.
Since there are too many posts about this and none of the info in one place (someone should put all the corrections in one post and name the thread something like "ocd markm layout corrections" or something so they are easier to find).
Or maybe I'm just a lazy bastard eh?
So...the question.
What are the corrections and mistakes on the markm layout?
I've had the OCD V4 and I want to build it as close as possible to the original.

-Transistor pinout (for the 2n2007),
-missing resistors,
-wrong caps (and capacitor types!) ,
hp/lp switch?
Can I get all in one place?
Thanks a bunch.
Cheers.

Mihajlo
Attachments
OVD LAYOUT_001.png

Mihajlo
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Post by Mihajlo »

Found everything I need.
Sorry about my stupid noob question.
Pedal works, and it is awesome!!!
Cheers

nezek
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Post by nezek »

I got my OCD before I really started building stuff.. but lately i've decided this thing needs some work.
I got V3, and with my setup it sounded kinda fizzy, other than that I loved it.

threw out the TL082 and tried a few things.. ended up using a burr brown IC, 2104 I think. lost the fizz and the pedal is overall quieter.

tried a few others as well.. LM833 would've been my choice if not for the burr brown.
*out of all the opamps I tried, I gotta say the 082 was the worse to my ears.. kinda made me wonder, even a 072 gave the same tone just with less noise..

Mihajlo
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Post by Mihajlo »

Hm... :hmmm:
I did put a socket for the IC but didn't try anything but the TL082.
I'll have to give it a try.
Cheers

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Post by slash555 »

i tried lm833 as you said! wow, it's better to my ears, little brighter what's just what i was looking for. thanks for the tip :applause:

what burr did you use? maybe opa2134?

nezek
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Post by nezek »

yup. that's the one. the tone is very similar to the lm833, a bit more low end and less noise.
I'm a P-90 guy.. noise builds up rather quickly :)

Mihajlo
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Post by Mihajlo »

I've built one more OCD (vero layout one) but I have a problem with the volume potentiometer.
Unity gain is just above 10-15% from zero!?
When I turn the volume knob half way it is so loud it's unusable even for a lead sound! (not to mention the decibels when it's all the way up).
Other than that it works great.
Only substitution is the 1n4841 in the place of the 1n34a (in the clipping stage).
I've tried different pot values - it doesn't help.
Anyone knows what's going on?

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Post by jfk1063 »

Hi,

I wanna build the ocd according to the below tagboard lay-out, but there seem to be differences with the vero lay-out. Some values seem to be different.
Can someone tell me if it is correct?

Thanks!
Attachments
OCD.png

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Liquitone
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Post by Liquitone »

Mihajlo wrote:I've built one more OCD (vero layout one) but I have a problem with the volume potentiometer.
Unity gain is just above 10-15% from zero!?
When I turn the volume knob half way it is so loud it's unusable even for a lead sound! (not to mention the decibels when it's all the way up).
Other than that it works great.
Only substitution is the 1n4841 in the place of the 1n34a (in the clipping stage).
I've tried different pot values - it doesn't help.
Anyone knows what's going on?

Since this is my first post ever i wanted to say hi and compliment you all on this excellent forum.

I've had the same issue with the volumecontrol where everything seemed to happen on the first quarter, making adjustment very hard.
I tried putting in a 100k log pot instead of the linear and that really helped,.
untity gain is now about halfway on the control and i can fine-adjust it much easier now mid-song during bandpractice.

pgm
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Post by pgm »

Hiya new to the forum :D
Planning on building this
Just need to check something before starting!
Are the black triangles facing downwards to ground? because I think its to ground but my friend thinks it goes to 0v?

Image


cheers

Krallum
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Post by Krallum »

Short answer: yes

ground is 0v, or rather a reference for which to locate other voltages. The notation is a short hand, that way we don't have a thousand wires crossing all over for all of the + and - connections. Besides in reality none of those wires would even exist. In application your ground becomes a strip or location on a board so its pointless to draw something on a schematic that isn't even there. Same goes for all of the +9v those are all the same battery or in the practical sense, the same strip on the veroboard.


Think of it as a distance. Say the distance from your house to your friends, is 9 miles, that doesn't mean that your house is at some mysterious null location, its just the reference to which the battery and rest of the circuit are connected.

pgm
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Post by pgm »

Alright cool thanks :)

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Post by nooneknows »

pgm wrote:Are the black triangles facing downwards to ground? because I think its to ground but my friend thinks it goes to 0v?
yes, and the vero you' re going to use is okay, I've built mine with this and it's ok, just py atention to the traces you have to cut.
Btw, I think the switch is not that useful, since I always used mine on Hi, I just took out the switch, connecting the two resistors in parallel.

pgm
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Post by pgm »

nooneknows wrote:
pgm wrote:Are the black triangles facing downwards to ground? because I think its to ground but my friend thinks it goes to 0v?
yes, and the vero you' re going to use is okay, I've built mine with this and it's ok, just py atention to the traces you have to cut.
Btw, I think the switch is not that useful, since I always used mine on Hi, I just took out the switch, connecting the two resistors in parallel.
Thanks guys, schooled on reading schematics :wink:

Does schematic sound good?
I noticed theres a couple of different ones?
Do they all sound as close to the original as each other or?

kungpow
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Post by kungpow »

I've built off the layout you posted and it sounds great! Can't speak for the others...

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