Not convinced with kempers pedal calibration: FIX NEEDED?

    Quote from paults

    Do you still have this problem if you push the pedal far enough to compress the rubber stops when you calibrate the pedal?

    Not sure if you are asking OP or me, but anyways I will post my answer. :)
    I would say that pushing the pedal far enough to compress the rubber exactly causes this problem, because it forces pot to value which is beyond normal pedal range. Kemper gets this out-of-range value and makes it new MAX. but is is NOT MAX of normal range. I came to one possible hardware workaround: take the rubber stops out and replace them with uncompressible material, so the pedal would not go out of range. But then we will loose ability to use the switch. :) I would really like to see how the Mission EP1KP is set up because it's construction is the same as my pedal - VOX/CryBaby. And they use the switch also....

    Quote from paults

    Do you still have this problem if you push the pedal far enough to compress the rubber stops when you calibrate the pedal?

    Yes, the springy-ness of rubber stoppers gives the same "partial return travel" as the spring-return of a push switch.
    Glad someone else has this experience (not glad for them personally, but glad the issue has been recognised and raised by another user)

    Kemper Amps should look into this, looks like a valid argument against constant calibration. Then again, I'm not too sure what the benefits are of the pedal constantly being calibrated.


    I have a wah pedal that allows you to calibrate dead zones. You activate calibration mode, then sweep the pedal within the range you want it to be in. After that, you click the toe button in order to exit calibration mode. At first, this was really hard for me to grasp, because pushing down on the toe button made it impossible to reach the highest 127 message. I then realised after reading the manual that you had to sweep as far forward as you wanted, then press the button with your hand, instead of pressing down with the pedal.


    Hopefully Kemper Amps gives this idea of dead zones some consideration. You can create dead zones both toward the heel and toward the toe, which is great.

    There are already dead zones automatically. Right now they are 5% of the current learned range at both ends.
    What's funny that such a pedal as shown in the opening post is actually a faulty design since it would also drive an analog effect the wrong way (it might be more forgiving, but still... )

    Quote from timo

    There are already dead zones automatically. Right now they are 5% of the current learned range at both ends.
    What's funny that such a pedal as shown in the opening post is actually a faulty design since it would also drive an analog effect the wrong way (it might be more forgiving, but still... )

    valid points, I do agree, and this design has been around for decades. Some of the major benefits of digital systems verses analogue is there is greater control and forms of "error correction" whether that's to combat analogue noise or something like the situation we have here.

    Quote from timo

    What's funny that such a pedal as shown in the opening post is actually a faulty design since it would also drive an analog effect the wrong way (it might be more forgiving, but still... )

    I agree that this design is rather not good, but those pedals are here and we would like to use them with KPA. And simple function of locking calibrated range would allow us to use our pedals. :)
    BTW, Isn't Mission EP1-KP (for Kemper) pedal of the same faulty design/construction? Maybe it works different, but it looks no different to CryBaby design.
    [Blocked Image: http://deluxeguitars.com.au//m…ssion-ep1kemper-2-400.jpg][Blocked Image: http://www.fullcompass.com/com…ducts/original/243867.jpg]



    @timo please, what is continuous calibration good for? And what's the purpose of calibration button / calibration screen, if after we calibrate pedal to desired range, KPA re-calibrates it afterwards to different values?
    And last and I think most important question is: Will we get some kind of "Lock range/Continuous calibration disable" button? Thank you!

    Quote from timo

    There are already dead zones automatically. Right now they are 5% of the current learned range at both ends.
    What's funny that such a pedal as shown in the opening post is actually a faulty design since it would also drive an analog effect the wrong way (it might be more forgiving, but still... )


    That's pretty cool, the Kemper is such an ingenious invention. Not sure why @slateboy is having the problem though, if this is the case. I'm pretty sure pressing down on the rubber bumper and the position the pedal moves to after you release (due to the bumper) would not be 5% of the pedal's range.

    I've calculated that my "dead" zone is about 8% at the toe-position.
    Whilst relaxed on the toe switch this equates to 92% of the full-range, going all the way to 100% when depressing that sprung-loaded switch. Heel goes all the way to 0% (the rubber bumper on the heel-stop is negligible)


    I wonder what percentage margin there is on the old crybaby's, which were always "active" unless the toe-switch was triggered, thus completely bypassing the device. I appreciate this is not a fair comparison with the Kemper, which is a different arrangement completely, but if someone was to convert their old crybaby into a Kemper control pedal (as im sure some users have done) it would become relevant.

    Using a pedal with this design as a conventional wah does not require a full value sweep for the effect to work consistently.


    With a Crybaby and other analog wahs, the pedal throw is not the entire range of the potentiometer sweep. It even is possible to "fine tune" the beginning/ending position of the potentiometer sweep range by turning the potentiometer a notch or two in either direction, compared to the position of the straight notched pedal attachment.

    Quote from slateboy

    but if someone was to convert their old crybaby into a Kemper control pedal (as im sure some users have done) it would become relevant.

    Yes, that's me. ;)


    Paults is true, for controlling KPA wah, there is no need for full sweep. But pedal is unusable for morphing, pitch and will cause problems with volume.

    Quote from warlus1

    question.
    the calibration is a "midi-algorithm" no?
    so min = 0, max = 127


    if it's true, maybe it s possible to set max = 115 (for exemple)?

    Quote from warlus1

    question.
    the calibration is a "midi-algorithm" no?
    so min = 0, max = 127


    if it's true, maybe it s possible to set max = 115 (for exemple)?


    Sorry for the double quote. This might cause problems with how the pedal sweeps through values, because by shortening the number of midi CC messages within the throw, it might result in jumps in inconsistent jumps in value. Are there any devices that accept this kind of truncation of the maximum (or boost in the minimum) midi value?

    So, after all this back and forth...is there a Kemper "approved" expression pedal(s) which will solve the issues the OP is having with the inconsistent calibration of his no-name pedal?

    Quote from Tritium

    So, after all this back and forth...is there a Kemper "approved" expression pedal(s) which will solve the issues the OP is having with the inconsistent calibration of his no-name pedal?

    I once blamed a missfunction of my Volume pedal calibration at the support.
    When the KPA started the calibration has to made new very often. ( I thought)
    Actual the problem was the "min" poti which was not always at the same mechanical position due the transport.


    Now I take care that no min volume is set, before I start to play.

    Just finished modding an old crybaby I had laying around. Mod worked fine, but I'm encountering the same issue as the OP. Kemper re-calibrates pedal on its own once it recognizes a newer "highest value" (i.e. when activating switch). So, I can only agree that it would be great if the KPA was not in constant calibrating mode [cf. Slateboy's post nr 8] 8)


    If that's not possible, I guess I'll just uninstall the switch and use the exp on its own ;)


    Cheers!

    But the switch remains at place so do rubber parts. Doesn't change a thing, if you use it or not.


    Anyway, I went a little deeper into this and I found out, that there are also pot tapers which do give 100% resistance from 3/4 to full turn.
    It look something like this:
    [Blocked Image: http://lh6.ggpht.com/_xtvfH1oX…ZdWvrZJRiYg/octavewah.jpg]
    http://www.diystompboxes.com/s…m/index.php?topic=88422.0


    I think if I had such a taper available I would not experience these problems and the switch would be still usable.
    With this kind of curve, the Crybaby pedal design does not look faulty at all. :) So my 1st question is answered. :)