Line 6 uses a very different kind of expression pedal than the ones you would normally find. I will describe the differences and what I did to build my own expression pedal for my POD HD 500.
Commonly an expression pedal would include a 10K Ω (ohm) linear potentiometer, a 1K Ω resistor and a TRS (tip, ring, sleeve) jack.. To use such a pedal you would need to use a TRS to TS (tip, sleeve) y cable, which is essentially a stereo to dual mono splitter cable. You would plug the stereo end into the device you are controlling, the ring side to the input side of a passive volume pedal and the tip side to the output of the same pedal.
Line 6 however implemented a design that allows their volume pedal to be hooked to their device with a single instrument cable. A very good idea indeed. The problem is that the Line 6 EX-1 expression pedal being plastic, in my opinion, may not hold up to the rigors of gigging or heavy handed usage.
Mission Engineering makes an expression pedal that will work with Line 6 devices and in my opinion would be road/gig worthy. Street price is $129.99. This is a great alternative solution. But as is the case with most artists, funds may be a bit slim.
As an alternative I built my own expression pedal with about 20 minutes of my time and a final cost of $50.50 USD. (Your cost could be between $50.00 to $65,00 USD and your time). Which is a far better deal than $130 USD plus delivery and/or gas.
To build your own you will need the following:
- 10K linear pot with a minimum of a 3/4″ (20mm) metal shaft (I recommend CTS pots for the high rate of cycle before failure) $12.50 USD
- Dunlop potentiometer replacement gear $5.00 USD
- 1/4″ Mono Jack $1.00 USD (I prefer Switchcraft)
- CryBaby Wah shell, used $32.00 ~ $47.00 USD
- 2 pieces of wire about 2″ (49mm) in length
Tools you will need:
- Dremel rotary tool with a aluminum oxide grinding stone (8175, 8193 or 932)
- Soldering iron or gun
- wire strippers
- diagonal cutters
- 1/2″ open end wrench
- 7/16 open end wrench
- hot glue gun
I like sourcing a CryBaby shell for 2 reasons, they are easy to come by and I can get them cheap. I usually source used ones from eBay. Same with the 10k pot and gear which I buy new. The price difference between a broken CryBaby and a used working one is negligible. In fact I have found broken ones that go for more than used ones on eBay. So buy carefully to keep your costs down. For the 10KΩ linear pot i use this eBay store. They provide the right pot to get the job done and the shipping is pretty quick.
If you get a late model CryBaby pedal you can usually use the gear off the existing potentiometer. But do not use the pot that is in the unit, as the taper is not linear and will produce poor results. If there is a mono jack that is not soldered to the board you can reuse that as well.
So here is the shell I used
I took out all the internals as I would not be using them. I kept the jack as this was an early 90’s unit that did not have the jack soldered to the board. The gear that was on the pot was worn so I used a new one. In the picture you will notice that it has a “D” shaped opening. This will require a modification to the potentiometer before we assemble the expression pedal. You can access the internal PCB by removing the base plate. Take out the switch, PCB, pot, etc.. Loosen but do not remove the cable holder that is used to tension the gear rack.
The CTS 10K Ω linear taper potentiometer has a round shaft and the gear fits only onto a D shaped shaft. Turn the shaft all the way to one side till it hits it’s stop. You will now use the Dremel with the grinding stone to shape the shaft into a D shape carefully. Be sure to wear safety glasses as you grind the shaft to fit the gear. At the bottom of the shaft the is a c-clip, be careful not to grind this off or your pot will come apart. You will grind the shaft into a “D” shape for the length of the shaft all the way down to the c-clip. Test the fit till the gear easily slips down the shaft.
Once the gear easily slips down to the base of the shaft use the hot glue gun to affix it to the shaft. In the picture you will notice the glue is on the end of the pot shaft.
Next install the pot and the jack into the shell. The pot will install with the gear able to engage the rack so that it will turn the pot. Tighten the nut to hold the pot in place firmly. Looking at the pot from the gear side make sure the pot is rotated all the way clockwise. Rock the treadle so that it is toe up to the furthest extent. Engage the rack to the gear and tighten the rack tensioner to hold the rack against the gear. With the pot and jack installed and the rack engaged to the gear we are now ready to solder.
Firstly, you will want to strip and tin your wires. Here is a video to show you how it can be done. On the pot you will notice that there are three connection lugs available. Looking at the pot from the gear side you will solder the right and center lugs together by bridging them with a piece of wire. I simply tined a longer portion of the white wire and soldered the 2 lugs together by passing the extra length through both lugs and applying solder. Next I soldered the other end of the white wire to the lug attached to the inner ring of the 1/4 inch Jack. The black wire I soldered to the left lug of the pot and the opposite end of the wire to the tip lug on the 1/4 inch jack. Completed this is what it should look like.
Next we will want to test to make sure we connected everything up correctly. Insert an instrument cable into the jack. Set your multimeter to test for ohms in the 20K range. Make sure the treadle is in the toe up position. Connect the meter so that the read lead is touching or is attached to the tip of the instrument cable that is loose. The black lead should be connected behind the separator that separates the tip from the sleeve. You should read 0.0 ohms. Rock the treadle so the toe is down and you should see the meter sweep from 0.0 ohms to somewhere between 8.4K to 9.6K ohms. If not check your connection. If it sweeps through the range mentioned then you’re ready to fasten the cover and connect it to your POD device.
This expression pedal will work with the following Line 6 devices
- Pod HD 400
- Pod HD 500
- Pod HD 500X
- FBV Short Board MKII
- TonePort KB37
- Pod Studio KB37
So for about $50.00 I built my own Line 6 compatible expression pedal that has quality components that can be used with my Pod HD 500 and also my KB37 keyboard controller. It will also hold up to the rigors of gigging and my tendency to be heavy footed.
*all product and company names are protected under trademark and copyright of their respective owners. ebay, Switchcraft, Line 6, Mission Engineering, Dunlop Manufacturing and CTS products are all mentioned in this article.