Oddfelow Effects - Caveman Overdrive  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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AAntonio
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Post by AAntonio »

mmolteratx wrote:Did this pretty quick, but I looked over it and it looks good, as long as the schematic is good. Uploaded to OSH Park. I don't guarantee that it works, but it's very likely that it does. Might be up to organize a group buy after it's verified and if there's enough interest. Will fit in a 125B for sure with battery and everything. Might even fit in a 1590B with a bit of ingenuity. Plus it doesn't look like a monkey designed it.

https://oshpark.com/shared_projects/uhVgxqEH

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the link does not work!!!

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mmolteratx
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Post by mmolteratx »

zedsnotdead wrote:Hi guys, sorry for the necro-post.

I built this thing some days ago, and I'd like to share with you some thoughts.

Here it is, built on mmolteratx OSHpark PCB (excelent work, thanks a lot! :D there's only just one thing - please check note @ end of post):
11666171_1012943032072043_3926986634665265484_n.jpg
Now a few notes regarding the sound.
1- I compared it vs OCD. Caveman seem a little darker sounding, but tweaking the tone control they sound almost identical.
2- I used a B100K pot for boost control. Only at around 80% CW you start to notice a "boost on/off" difference. Lower than that rotation it doesn't do much for boosting the signal. What I mean is if you have the boost pot @ 50% and step on the "boost" footswitch you will hear almost no difference in volume. You only get it significantly above 80%.

So what I was wondering is:
a) how do I make it less dark sounding? Should I change the tone cap? Should I change the pF cap on the feedback? Both??
b) do you think that using a B50K pot for boost control could give a better "range spread" for it?

Thanks!!


@mmolteratx
Boost pot/trimmer connections are backward. 1 is 3, and vice versa :)
You'd need to use a reverse log pot. 50k may or may not work any better. To make it brighter, you can lower the value of C2 and C5. Might want to start with C5, as changing C2 will also change the nature of the distortion. The trimmer is just mislabeled on the board as well. If you use an actual trim pot, you shouldn't have to worry about the numbering. Simply swap 1 and 3 if you're adding a pot off board.
AAntonio wrote:
mmolteratx wrote:Did this pretty quick, but I looked over it and it looks good, as long as the schematic is good. Uploaded to OSH Park. I don't guarantee that it works, but it's very likely that it does. Might be up to organize a group buy after it's verified and if there's enough interest. Will fit in a 125B for sure with battery and everything. Might even fit in a 1590B with a bit of ingenuity. Plus it doesn't look like a monkey designed it.

https://oshpark.com/shared_projects/uhVgxqEH

[ Image ]
the link does not work!!!
Oh noez!!! For some reason all of my shared projects had their settings reverted to private. Should be fixed now.

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zedsnotdead
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Post by zedsnotdead »

mmolteratx wrote: You'd need to use a reverse log pot. 50k may or may not work any better. To make it brighter, you can lower the value of C2 and C5. Might want to start with C5, as changing C2 will also change the nature of the distortion. The trimmer is just mislabeled on the board as well. If you use an actual trim pot, you shouldn't have to worry about the numbering. Simply swap 1 and 3 if you're adding a pot off board.
I tried 50KB, so I start noticing the signal boost around 40% now. It fits me :)

About the caps, I lowered C8 to 22nf. There was a slight jump on the upper mids IMO, but still... C5 is next!

I add the boost pot off board, as you can see on the picture. And that swap is exactly what I did :)

Can't thank you enough for your time, work and help mmolteratx!
Thank you so much! :D

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Ichabod_Crane
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Post by Ichabod_Crane »

Very old topic, but I found this video (old, too):
It's a version 2 of the Caveman. Main distortion plus a clean boost.
At minute 2:22 https://youtu.be/si4IyG-MlS8?t=142 you see how much different the PCB is now! Nothing to do with the Fulltone OCD.
There are four TL072, I can't see any "clipping diodes". A diode 1N4001 (?), maybe as reverse polarity protection.
The Pre / Post Boost switch it's a simple three lugs. There's an internal slide switch for bass boost.
There's a peculiar switching way, perhaps. I see transistors and diodes on the 3PDT footswitches and a pair of relays.
Three electrolitycs one in the 9v and one in the Vref? (Other two electrolityc caps are close the relays, maybe not in the schematic effect).

Some chance to get the schematic?

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