# CDXL reissue (DOD440) trimpots to full size pots?



## Dali (Feb 25, 2020)

Hello, I was wondering...

I finished my CDXL reissue (DOD440) and before boxing it I was wondering if it's a good idea or not to change those 2 10K trimpots to "real" ones accessible on the top of the box like normal ones.

I'm asking because I felt my different guitars really needs different settings there and being hidden inside the box could be frustrating in the long run.

I saw someone just drilling holes on the back of his enclosure to gain access to such trimpots but still looks inconvenient with my observation (each guitar needs a different value).

If I ever do such modification do I only have to replace the trimpots R20 and R23 with B10K, put some wires to reach the connection and that's it?

Thanks for helping me with a first "mod"!


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## Dali (Feb 25, 2020)

I would say the "emphasis" for lack of a better word. The documentation has even the schematic if it helps anyone find better words. English is a second language for me...

As for the trim-to-pot, which one is the correct pinout? Red or Green? Or another variation(1B,2A,3C)?


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## Dali (Feb 25, 2020)

thewintersoldier said:


> The first one in red. If in doubt check the schematic.



Thanks for the information. I sadly can't really read a schematic... 
So I will trust you.


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## zgrav (Feb 25, 2020)

use the first one in red.  if you don't like the way it "turns" out, then swap the outside wires on the pot.


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## Chuck D. Bones (Feb 25, 2020)

I'm a fan of moving trimpots to the front panel.  Not appropriate for all trimpots, but for these I would do it.  One caveat: don't expect the full range of rotation to be useful.


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## Dali (Feb 26, 2020)

Chuck D. Bones said:


> I'm a fan of moving trimpots to the front panel.  Not appropriate for all trimpots, but for these I would do it.  One caveat: don't expect the full range of rotation to be useful.



Do you mean that if the trimpot had 10 "values/positions" only 3-to7 would produced different sound for example?

And if so would a different value instead of 10K for the pot would be more interesting? A lower value?


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## Chuck D. Bones (Feb 26, 2020)

Quite possibly.  At the ends they might sound the same, or not good, or no sound at all.  Depends on the circuit.  In the CDXL reissue, R23 sets the tuning range for one setting of the DIRECTION switch.  I'll be damned if I know what R20 is supposed to do.  Maybe put a hard limit on the sweep.  I think they would be set once and forget.  Try 'em and see.


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## Cucurbitam0schata (Mar 11, 2020)

Just finished my CDXL Reissue Envelope Filter - so, so fun. I'll toss out a build report soon. I'm already thinking about my second build, because messing around with right trimpot produces wild results (especially when turned way up and the toggle switch is in the "down" mode). Would be fun to have that on the front. 

@Chuck D. Bones - any chance you got your trimpots swapped when you were talking abour R23/R20? I'm hoping you did, otherwise, something's extra goofy with my pedal! For me, R20 on the right is really fun to mess with... R23 has me scratching my head. 

So, questions for the hive mind:
 - What exactly does R23 do?
 - What exactly does R20 do?


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## Chuck D. Bones (Mar 11, 2020)

IC2.2 is the peak detector that converts the envelope, the instantaneous loudness, of the guitar signal to a voltage that is then used to sweep the filter.  R20 sets the bias of the peak detector amplifier.  R20, along with the LEVEL control, sets whether, and how much, that amplifier is driven into saturation.  When that amplifier saturates, it could load IC1.1 in such a way as to cause distortion, just a guess.  I would think that mainly, it would cause the filter sweep to go just so far and stop there when you strike a note, then tail off.  In other words, instead of a smooth filter sweep, the sweep would be more abrupt.  Maybe you could upload a sound sample.  

IC2.1 inverts the envelope signal, or not, depending on the position of the DIRECTION switch.  R23 sets the bias for IC1.2 when the switch is in one position, and does nothing when the switch is in the other position.  It kind of acts like another RANGE control, but only for one position of the DIRECTION switch.


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## Dali (Aug 30, 2020)

I still haven't boxed that one and while doing the graphic, I was wondering how to label R20 and R23...

Maybe:
R20: Area ?
R23: Mud ?

Any suggestion? How did it ended for you @Cucurbitam0schata ?


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## Cucurbitam0schata (Aug 31, 2020)

Once I got the internally trimpots dialed in - we were all good. I think initially, I had some extreme settings with the trims with the switch in the "down" mode, and the pedal sounded all out of whack. Once I realized I could dial things back, it was fun to intentionally manipulate/bludgeon things. All of a sudden, the "broken" sounds sounded way cooler.   

I like your names, sounds appropriate to me. Mud and Area. Synonyms that come to mind... 

mud/cudgel/club/bludgeon/boomer/'sploder/splatter
area/space/expansion/berth/frontier/great beyond/warp factor

Good luck! Looking forward to your boxed build. Someday, I'll build another with the trimpots turned into top-pots.


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## daeg (Oct 8, 2020)

What would you guys say the the range of useable sweep for R20 is?


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