Recently, I ended up with a broken crybaby wah. I was already lucky enough to own a 70′s thomas organ crybaby which I love, so sacrificing this second newer crybaby for a project seemed like a fun idea. Since the crybaby chassis is extremely rugged and I like the action of the pedal, I set out to turn it into an expression pedal for my El Capistan. This article assumes that you have experience soldering and using basic tools like wire strippers, etc. Of course, always observe proper safety precautions and wear safety goggles while working on any type of electronics.
 Here’s my wah on the workbench. |
 First, opening up this box couldn’t be easier. Just remove the 4 thumb screws from the back plate and remove the plate. |
 Then, unscrew the two jack nuts from the input and output jacks and also remove the single screw holding the PCB (printed circuit board) to the chassis. Unplug the cable connector, remove the PCB and set aside. |
 Connect your treadle pot to a standard 1/4″ TRS (tip/ring/sleeve) jack according to the schematic in tech corner #1. Desolder all wires from the pot and switch and set aside. |
 The “sleeve” of the jack is ground, so first connect that to the pin of the post closest to the footswitch. Then, connect a 1k resistor to the wiper (center pin) of the pot. Connect the resistor to the “tip” of the jack. Lastly, connect the pin of the pot closest to the jack to the “ring.” You’ve got an expression pedal! |
Watch the youtube video for a walkthrough of the build process and an El Capistan demonstration with our completed diy project:
Happy shredding,
-terry
*All product names used in this article are trademarks of their respective owners, which are in no way associated or affiliated with Strymon or Damage Control, LLC.
Tags: analog delay, brigadier, builder, delay, delay pedal, diy, dtape, echo, effect, effects, effects pedal, el capistan, electrical engineering, expression pedal, how to, maker, orbit, pedal, stompbox, strymon, tape delay, tape echo, video
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Great Info!
Thanks!
I own an el Capistan and LOVE it. I saw your “How to make an expression pedal out of a broken wah” and I was wondering if you’ve ever tried converting an old Sewing machine pedal into an expression pedal? I have very limited space on my board, and the sewing machine pedals are so much smaller than Wah enclosures. I have yet to find any schematics on how to go about converting a sewing machine pedal. Any ideas? Is it really just installing a 1/4 jack and changing out a pot for a 10k pot or so? Any help would be great. I love the El Cap and really want to be able to put an expression pedal on the board, I just don’t have room.
Thanks so much guys… and I hope you can help.
I look forward to hearing back from you.
Paul
Great tutorial! On tech corner 1 you mention that the EV5 among others has a second pot on it to allow you to fine tune the range of sweep of the main pot. Could you show us know how to do add one of these extra pots to the above example?
Any pointers would be much appreciated!
Jeremy
Thanks, Terry! Very inspiring. I have an El Capistan and had briefly used an Ernie Ball Jr. Volume Pedal as an Exp. pedal. The 250k pot made it almost unusable, so a quick trip to “The Shack” today yielded a 10k pot, a stereo jack and a 1k resistor.
It only took about 2 hours to modify the EB and have it up and running with the El Cap… amazing fun!
The pot mount on the EB was the trickiest part, since the threaded shaft on the 10k pot was too short to allow the nut to lock it in; I ended up counter-boring the alum block a little to accommodate it, drilled a hole for the TRS jack on the front left, and voila… a solid aluminum expression pedal providing tons of versatility for the delay. I prefer it controlling the Mix function, but who knows what tomorrow shall bring. Fun stuff!
I really love the El Cap… even moreso, now.
:)
Hi Everyone, thanks for all of the comments! This is really great.
@Paul, It’s really just about getting the potentiometer to turn when you move your foot. The electrical setup is simple, but getting the pot to turn mechanically might be tricky.
@Jeremy, this second minimum value pot would be set up as a series variable resistor in the connection to ground (the shield of the jack).
@Derek, Nice work!
Happy Shredding,
-terry
I have a broken line 6 ex-1 and I want to replace the 20k pot with the 100k pot from the crybaby and put it back in the wah incosure. Will this work?
That will work just fine if you follow the wiring instructions above. If the 20k isn’t damaged that will work fine as well, no need to steal the pot from the crybaby.
One question: I would like to use the on/off switch under the pedal to also control some effect (on/off), using the second (now empty) opening of the original wah.
Could you give me some info on how to do this?
I would like to use this modded pedal along with my MFC101 Pedal board (for the Axe-FX Ultra), which has some decent wahs on board, so I could mimic the switching behaviour of a Wah-pedal when stomping on it.
Thanks,
Reinhard
Hi Reinhard,
It’s possible most likely, however I am not familiar with the MFC101 midi controller so I can’t give more specifics. The basic idea would be to wire the two switch poles from the unused wah switch to the second 1/4″ jack.
Terry
Hi Terry!
Thank you for your response!
One question remains …. what is the 1K resistor for, that you mention in your video?
Thanks,
Reinhard
Hi Reinhard,
The 1K simply serves as a current limiting resistor in case of a short.
-terry
Hi!!
I was able to modify my old EX1..I put a pair of TRX female Jaks, a 50 k volumen pot and I leave the original 20 k pot…and it works fine controlling my Brigadier and El Capistan..both at the same time, no bugs,,works fine ..I hope there will be no future electric damage for my devices.
Best!!!
Hi Terry!
First i’m gonna say, you guys make some amazing pedals – i’m so excited about the sounds i get from my bluesky.
I was wondering where I should if I want to buy the components to build an expression pedal. I don’t think my local guitar store have these components. Do you have any recommendations?
Hello Terry!
I want to made a expression pedal for my line 6 m5…
what i need? a mono or stereo jack? i read that the pot is 10K. and the 1k resistance?
Thanx!
Line6 does their expression pedals differently than pretty much everyone else. You use a mono cable and a 10k pot to vary the resistance from tip to sleeve.
so for the line6 style would you use the same trs input jack but use a mono cable? and the crybabies pot would have to be changed to the 10k pot or would the original pot work?? Thanks allot!! I have 2 extra crybabies and would rather not by the plastic one that said company makes…
I am building an expression pedal for my boss bass synth. I am using an old volume pedal but he value is to high I believe (250k audio). I used a stereo jack and wired it according to you schematic and used a stereo cable to connect. Nothing. I then used a mono cable and actually got an effect but not like it should. I guess my question is what value and type of pot would be best and should I use a tsr cable or standard mono?
Hi Robbie, you would have to know what type of expression pedal input the bass synth is expecting. I’d consult the BOSS manual and see if it recommends a standard expression pedal with a TRS cable.
Terry, I have modified a Cry Baby Wah to an Expresion pedal per your instructions, and of course it works! However, the sweep on the pedal is extremely short, making it unusable in practical terms – it goes from min to max with a very slight touch to the pedal. Is there a way to change the sweep so it is longer using resistors, or do I simply need to replace the original 100K pot with a 10K pot? ALSO, If I replace the pot should it be a linear taper pot and is 10k the right value?
Hi Brian, you’ll want to replace it with a linear taper pot to get a more even sweep. 10k or 100k will work.
[...] has made a great post about converting a Cry Baby to an expression pedal. I just wanted to [...]
Hi, nice blog and site! I have a question about the resistor. What kind of effect is it on the 1K? Is it important to choose the right one?
Hi Terry. Thanks for this article. Very informative. Would a 2k resistor do the trick instead of a 1k. I have a few 2k’s lying around. Also, would a univibe replacement pot do the trick for a 10k pot sweep? Like this one: http://picclick.com/NEW-Dunlop-Univibe-UV1FC-160615320911.html I can’t tell if it’s linear or not.
Thanks again. Love your pedals.
A 2k would probably be fine. That 10k pot should work great as well :)
Thanks terry. I might as well buy some 1k resistors while I’m at it. Are the carbon film? And what wattage? Thanks for your help. This is gonna be fun.
I just used this to solder up an expression pedal. Thanks for the info, I greatly appreciate it!
So if I wanted to do this for to control my Line 6 DL4 what would be different from what you laid out above?
Thanks.
I just took my crybaby, opened the back, and moved the pin connector over two places to the left (which bypasses the battery and who knows what else). After that, it actually works as an expression pedal. However, the pot makes it so that there is barely any sweep to it. However, this can be a pretty cool effect in itself with certain midi parameters so it is a free and totally reversible mod. Just thought I’d share.
Hi,
I have a Line6 M13 and an under utilized Vox Wah. I’m wondering if these 2 combinations would work? Mono\Stereo?
Please advise.
Thanks \m/
I am trying to build the expression pedal from an old CB 535Q and I was only able to get a 3 conductor 1/4″ stereo phone jack. Will this work?
A 3 conductor 1/4″ jack is TRS (tip/ring/sleeve) and is exactly what you need :)
thanks Terry.
So is a stereo cable required for this to work???????
Yes, a TRS stereo 1/4″ cable.
This is great! However, I’d really like to install another jack to control another pedal simultaneously. Is this possible?
If both pedals are Strymon pedals it should work. With other brands, all bets are off because the control voltage specification could be different.
A caveat to this is that you’ll likely create a ground loop and possible noise between the pedals by ganging them together.
That makes sense. Thanks anyway!
Can anyone walk me through how to do this with a crybaby 535 and a stereo guitar jack?
The pot on mine looks different so I’m not sure where the wires go.
Please email me at guitarest@aol.com if you can help. Thanks
Wooow… speechless i was going to buy a line (cheap) 6 expression pedal for my m9 but now i think i´m going to just undust my old cry baby..3 questions though…1. do i need a new pot or the one in the cry baby will do the thick? 2. the resistance is necessary for this EP1-L6 clone and 3 . the jack on the cry baby is a regular, mono (TS) guitar cable…can i use that?? thanks terry your are indeed the man!! by the way i reckon They are wired Tip and Sleeve.
Hi Anthony, what does the pot look like? Not familiar with the innards of the 535 specifically.
Hi Gerard, the Line6 ep-1 is a non-standart expression pedal design. I believe it uses a 10k but I am not certain about that. I know that is does use a standard TS cable (not TRS) and simply varies the resistance of the pot between the tip and sleeve.
Thanks for the great article! I have an EV-5 around that needs the potentiometer replaced. Do you have any idea what the specs for that pot is? The pot that shipped in mine is made by Alpha and is stamped with “8h3″ (the 2nd pot that adjusts the range is stamped with “8h4″) but I haven’t managed to find any specs just yet.
Are there any minimum / maximum specs that I should keep in mind or is a pot a pot and they simply vary by size? I believe the pots in the EV-5 or other wahs are described as rotory potentiometers. Is any difference between the form factor of such pots or are they all the same?
Any suggestions for manufacturers of pots that are better quality than others?
Thanks in advance for you help!
I’m looking to convert an Ernie Ball volume pedal to be an EV-5 equivalent, so I ordered the EV-5 pot as a spare from Roland UK (current part number is 01678156). The pot has no obvious manufacturer mark and is labelled “10kΩB”. I’ve measured the resistance from “off”/-150° to “full on”/+150° in 10° increments; the pot reads <1Ω from -150° to -40° and 8.82kΩ from 60° to 150°, and from -30° to 50° the values are 1.01k, 2.11k, 3.07k, 3.98k, 4.97k, 5.95k, 6.84k, 7.90k, and 8.75k. So there you go – highly non-standard, flat at the sides and linear in the middle.
Hi Terry,
What about the same except using two pedals simultaneously (same brand) in order to use the expression feature for both. A la Pigtronix Dual Expression Pedal
We could reuse both jacks and the switch on the pedal.
What is your point? Could you show us hte way to achieve this?
Thanks in advance!
Hi! i have just done it, and have tried it with a digitech rp50 for the whammy effects. but instead of having the signal all dry at heel position and all wet at toe position, its only full wet in the middle and stays all dry in both heel and toe position. im using a stereo cable. what can i have done wrong?
thanks
-btw, i’ve used a stereo jack like this one: http://www.synthrotek.com/wp-content/uploads/2010/11/amp_stereojack_id.jpg
does it matter?
Can’t wait to to convert my Boss FV-60 to a double CV pedal. One question- how do I know which pin on the pot is ground, just in case they aren’t labeled? I have a little knowledge of electronics and schematics. Once I know that I can do the rest.
@Ron, if you watch the video, at the 3 minute mark, terry wires up the ground connection. On the pot, it’s the pin all the way to the left.
I would like to convert my soon to be faulty crybaby into an expression pedal for my line 6 M13. I know they use a mono jack instead of TRS jack. Can this be done in a similar way to your tutorial above but wire the jack socket differently to suit the M13. Thanks.
There’s one thing i’m not understanding – did you use the original 100k pot in the video? Where would you get a 10k pot that would work in the crybaby, with the treads?
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