SOLVED - Mission Expression Pedal question

  • Hi Guys,


    I bought a used Mission Expression pedal a while back on ebay and have never been happy with the taper of the pot. It seems to go from off to on but the space in between is a no man's land. Looking at the calibration bar on the Kemper, it looks like the pedal has an audio/log taper pot instead of a linear pot.


    I have been quite vocal about how shit this pedal is in the past but maybe I have been wrongly criticising it.


    I was about to change out the pot for a new one so I loosened the nut holding it in place and lifted it out (still fully wired) just to take a look at the back of the pot and see if there was any specification markings on it.


    WOAHA hold on Tonto - it says Dunlop :huh:and when I look up the part number online it comes back as 10k linear pot for Cry Baby Wah. =O


    There are two possibilities here:


    1 - (and probably most likely) the guy I bought it from had tried to change the pot before and fitted a Dunlop Wah pot which in theory should work as it is 10K Linear just like the Mission. If that's the case his soldering technique is fantastic because it looks like factory soldering.


    2 - the reason people say the mission pedal feels like a wah is because it IS a wah. 8| It is literally a Crybaby casing and it may even be a Crybaby pot. Which would make the retail price of the EP1 a total rip off. i.e £130 for a Crybaby with most of the circuit removed V £80 for one with everything still in it but you can take it out yourself and change the jack socket from TS to TRS for about £4.


    Could someone with a Mission expression pedal take a look inside and tell me if yours also has a Dunlop pot in it?

  • I shared this post in the Kemper Facebook group too and Eric Tayetaye told me that his Mission pedal is also just a regular Dunlop Wah pot inside it. He also said he has built 3 other pedals using the same Dunlop replacement pot and they all function exactly like the real Mission. So on that basis it does seem like Mission are totally milking it on cost. It would be much cheaper to just by a regular Crybayby, disconnect the PCB and change one of the jacks for a cheap stereo plug. :huh:


    Anyway, the other thing Eric pointed out is that the pedal type affects the taper. He described it as one is for volume and one is for wah, whammy etc. I was all ready to tell him he was talking nonsense and the pedal type was just about polarity as page 62 of the reference ma manaual says:


    “Pedal Type 1” is also preselected, which fits nearly all regular expression pedals. If you are using an expression pedal with reversed polarity (e.g. Yamaha™), please select “Pedal Type 2”. Wrong polarity could cause a sub-optimal response curve."


    However, fortunately, before being a smart ass I decided to test it. And....... he was absolutely right. Although the manual says that Type 1 works with "nearly all regular expression pedals" and the mission is a recommended pedal for the Kemper (which would make you think it would qualify as "regular"), this gives it a very Logarithmic taper which makes it virtually unusable for anything other than on/off type control. Setting a specific value for morph or volume was damn near impossible. However, when I changed to Type 2 the Mission that I was ready to throw in the bin suddenly started functioning like a real Linear taper expression pedal. I can now use it for volume and morphing and it works just as well as my cheap as chips (1/10th of the price second hand) Zoom pedal ^^


    So here are my take aways from this whole experience:


    1 - yes the Mission pedal really is just a cry baby with the guts ripped out but costing nearly twice the price. In future I will just by a used Crybaby on ebay for peanuts and rip them out myself :)


    2 - either my Mission (which is actually the SP1 RJM but it's basically the same as the EP1 KP) is accidentally wired with the wrong polarity or Mission pedals should be set to Type 2 in the KPA


    3 - Someone needs to update page 62 of the reference manual to explain the polarity and what "sub-optimal response curve" means in the real world. ( Burkhard could you look into this or pass it on to the relevant person please)


    4 - I have been telling people that the Mission expression pedal has a really awful (bordering on unusable) taper and strongly recommending people don't use it. The truth is it doesn't as long as you set the correct Pedal Type in the KPA



    I hope this helps anyone else that is struggling with a Mission or any other expression pedal not responding as expected.

  • Wheresthedug

    Changed the title of the thread from “Mission Expression Pedal question” to “SOLVED - Mission Expression Pedal question”.
  • Dunlop crybaby wah uses a 100k pot. I just converted one to a expression pedal. I removed the 100k pot and ordered the 10k pot that Mission uses. 10k is what you want in an expression pedal. Works great for me

    Thanks. Sorry I just noticed this reply. I think it depends which Dunlop Wah you have. Some have 10K pots others have 100k or even 150k.