Expression Pedal Cables

  • Hi folks, this might be a bit left field but bear with me.

    I have a Mission SP-1 RJM which I am using with my remote. As far as I can make out from the specs the SP1 RJM is exactly the same as the EP1 KP except that the RJM has a TRS out for send 2 while the KP has a TS. None of this matters if you only want to use it as an expression pedal. However, if you want to use the switch to turn effects on and off etc it does. Neither a Standard TRS or TS cable will work with the Remote as the Tip and Ring seem to short out and confuse the Remote. RJM get round this on their PBC when using Mono/Stereo effects by using what Ron calls a Ring Disconnect cable. This is a cable with the Tip and Sleeve wired as normal but the Ring only connected at one end. I've used it on RJM stuff before and it works. I thought it might also work between the SP1-RJM and the Remote but it doesn't.

    Anybody else tried this?

    If so how did you solve it?

    I'm thinking my next try might be to disconnect the Ring at both ends and failing that connect the Ring to Sleeve at one end rather than leaving it disconnected.

    Does anyone know how the Remote's switch jacks are wired? ( @burkard ? )

  • PROFILER and Remote expect the contact between tip and sleeve if it's a mono switch. Stereo switches have an additional electrical contact between ring and sleeve.

    If the toe switch in your pedal closes the electrical contact between tip and ring, you could either change the cabling inside the pedal and solder the internal wire connected to the ring of the socket to the sleeve instead. Or you use a special cable with TRS jacks wired tip to tip and ring to sleeve.

  • Excellent thanks @burkard

    I’ll experiment with that. I’d rather not mod the pedal itself so that I can still use it with the RJM Mastermind if required.

    Am I right in assuming that the special cable would have sleeve connected at the pedal end and ring but no sleeve at the Romote end? As opposed to sleeve at the pedal connected to both ring and sleeve on the remote.

  • I think, you need to connect the ring contact of the pedal to the sleeve contact of the Profiler to make it work.

    If you take a TRS cable with three wires and exchange the wires soldered to ring and sleeve in one TRS plug, the cable should work in both directions. I'm wondering if you could even find such a cable pre-configured somewhere, as such cables are sometimes used to twist the phase of a balanced connection, if needed. But these might be custom made.

  • @Burkhard thanks for all your help. I thought I should update you on the outcome.

    It turns out that the switch on the Mission SP1 - RJM should work just fine with any regular stereo cable. The reason I was having a problem was much simpler than needing a specially wired cable! I should have checked this earlier but didn't think about it until I had wired several cables - none of which worked.............

    The actual switch in my pedal was broken :rolleyes:

    I have now replaced the switch and it works fine. I haven't managed to get the LED to work properly though .It only lights momentarily when I push the pedal then goes off again when I release. I''m not sure if wiring it differently would fix that but I'm not going to lose any sleep over it regardless.

    The only other thing I find a little strange now is that my new switch changes the KPA (for example turns on/off a Stop slot) when I release the pedal. The switches on the Remote change when pushed rather than released. Again, this isn't a major issue but I'm curious as to why this happens. Is it because I am using the wrong type of switch or is it because the Remote uses some form of internal programing to accomplish the change.

  • Ok, I'm glad, you figured that out!

    That the PROFILER switches, when you release the button instead when you push it is indicating wrong polarity setting in the menu. The PROFILER expects momentary switches. Polarity "normal" is related to switches with electrical contact closed while the switch is idle and momentarily opening the contact while you press. Polarity "inverse" is related to switches with electrical contact open while the switch is idle and momentarily closing the contact while you press. If you select the wrong polarity for your switch you have exactly the problem you describe.

    I don't understand which LED you are referring to!? The Mission SP-1 RJM doesn't seem to have a LED by default.

  • Thanks. The polarity part makes sense and probably explaines why the LED was constantly on with the briken switch but is not off unless actually pressing the switch.

    The SP1-RJM does have an LED as standard. I'ts one of the things that's specific to it so that the RJM controllers can send a signal to the SP1 to reflect the status in the RJM preset.

    Co-designed by Mission and RJM, the SP1-RJM is an optimized version
    of the SP-1 switching expression pedal for the Mastermind GT and
    Mastermind PBC MIDI Controllers
    Expression and switch outputs on the pedal connect to inputs on the rear panel of the Mastermind. The expression pedals can be used to control external MIDI effects such wah, whammy and volume.
    The integrated toe switch can be used to turn effects on and off, or toggle between effects. An LED on the front of the pedal is signaled to by the Mastermind and can be used to indicate state. For example, you can tell if your wah is turned on and the expression pedal assigned to it. One pedal can be connected to the Mastermind PBC and up to four pedals can be simultaneously connected to each Mastermind GT."

  • Yes, I guess that is really a RJM custom solution.

    You could only monitor the signal chain in the Remote's display OR redundantly assign one of the four Effect Buttons to that very same effect module and watch the status of it's white LED.