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Martin WalkerModerator
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Expression Pedals not generating the full range of MIDI Data
      #322584 - 10/07/06 03:43 PM
A lot of people seem to have problems after plugging in volume/expression pedals into various keyboards, and resort to sending them back, buying a different model, sending it back, buying a different model. Given that the vast majority of such pedals simply house a potentiometer with a rack/pinion gearing system that rotates it over its full 270 degree travel as you push the pedal from 'full on' to 'full off' position, there really can't be much wrong with any pedal, and there isn't.


Here's one to show how little you normally find inside:



Most modern keyboards convert this pot movement into MIDI data rather than sending audio data through the pedal, which makes it easier to identify the cause of the problem. When I reviewed CME's UF8 keyboard for SOS August 2005 I plugged in my existing pedal and found it only generated MIDI outputs data between #127 ($7F) in the full 'on' position and #70 ($46) when I pulled it right back to the full 'off' position. However, it generated the full #127 ($7F) to #0 ($0) swing when plugged into other devices including my Kenton Control Freak.

The reason? Unless your pedal features some sort of separate range adjustment knob, the only reason to explain this is that the wires connected to the wiper (moving connection) and 'high' end of the pot are wired the wrong way round for your particular keyboard (sadly, manufacturers haven't adopted any standard, so apart from buying the pedal they recommend you normally only find out the hard way). There do seem to be a few such pedals that don't have captive leads, in which case remember that you need a stereo TRS (Tip Ring Sleeve) jack to jack cable.

Most pedals contain a 10K ohm or similar value pot, with the bottom end of the pot connected to the screen of the cable, and the top and slider either connected to the tip and ring of its captive TRS-wired jack lead or the other way round (top to wiper and slider to tip).

So, all you have to do to get an expression pedal working with any keyboard is to swap these two wires over. You can either do this at the pot end (black and red wires 'A') after first opening up the pedal, or inside the captive jack plug (black and red wires 'B'). It took me about five minutes with my soldering iron:



Those that don't fancy soldering can buy a foot pedal adaptor cable that you attach to the existing pedal cable - one suitable model is the FC7 Foot Pedal Adapter from Ashby Solutions ( http://music.ashbysolutions.com/misc.html ).

For those about to buy a pedal, here are some guidelines that I've checked as far as possible, to save you the inconvenience of five minutes soldering


FOOT PEDAL CONTROLLER COMPATIBILITY

KEYBOARD MANUFACTURER: Clavia (Nord), CME, Emu, Kurzweil, M Audio, Novation, Oberheim, Roland, Voce (+some pre-1995 Korg products).
PEDAL WIRING: Wiper of pot connected to plug Tip, top of pot connected to plug Ring, bottom of pot connected to plug Sleeve.
PEDALS THAT SHOULD WORK:

M Audio EX-P (has polarity switch) www.m-audio.com/products/en_us/EXP-main.html
Roland EV-5 www.roland.com/products/en/EV-5/index.html
VP 3 www.bck.co.uk/htm/Pedals/pedal1.htm
Lead Foot LFX-1 www.thomann.de/thoiw2_lead_foot_lfx1_prodinfo.html


KEYBOARD MANUFACTURER: Kawai, Korg, Yamaha, some more recent Clavia products (that now offer support for both 'polarities' of expression pedal)
PEDAL WIRING: Wiper of pot connected to plug Ring, top of pot connected to Wiper, bottom of pot connected to plug Sleeve.
PEDALS THAT SHOULD WORK:

M Audio EX-P (has polarity switch) www.m-audio.com/products/en_us/EXP-main.html
Korg EXP-1
Korg EXP-2 www.korg.com/gear/info.asp?A_PROD_NO=EXP2
Korg XVP-10 www.korg.co.uk/products/accessories/xvp_10/acc_xvp10.asp
VP7 www.bck.co.uk/htm/Pedals/pedal1.htm
Yamaha FC-7 www.yamaha-europe.com
Behringer FCV100 www.behringer.com/FCV100/index.cfm?lang=ENG)


If anyone has tried other pedal models with other keyboards not mentioned here, let me know and I'll update this list.


Martin



UPDATED 12/07/2006 Added Lead Foot LFX-1 pedal thanks to Alexx and Kawai keyboards thanks to Kayvon.

UPDATED 04/09/2006 Added Voce products to list, and some pre-1995 Korg products.
N.B. Kurzweil keyboards apparently also expect a 10K ohm pot, and won't provide a smooth, full-range adjustment even with a correctly modified pedal that uses a 50K or even 100K component. Thanks to Bruce Wahler who manufactures the Ashby Solutions FC7 adapter mentioned above for this information.

UPDATED 14/05/2007 Added Behringer FCV100 to list thanks to SteveECrane.

UPDATED 31/08/2012 Added Novation keyboards to list - the recommended pedal for these is M Audio's EX-P or Moog EP-2

UPDATED 18/02/2013 Added M Audio keyboards to list, and added 2nd Clavia entry to reflect the fact that more recent Nord products now support both 'polarities' of expression pedal.

Keep that info coming!

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Martin WalkerModerator
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Re: Expression Pedals not generating the full range of MIDI Data new [Re: Martin Walker]
      #748554 - 29/06/09 02:01 PM
Thanks to SOS forum user SteveECrane for proving this link to the wiring of Roland's EV-5 Expression Pedal, which has a second pot so you can set the minimum volume to the level of your choice:

www.midiguitar.net/group/EV-5%20Info/ev-5-schematics.png



Make sure you set this additional pot to its '0' value to ensure you get the full MIDI data control range!


Martin

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Martin WalkerModerator
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Re: Expression Pedals not generating the full range of MIDI Data new [Re: Martin Walker]
      #750665 - 07/07/09 11:25 AM
Sadly Ashby Solutions is closing, so their FC7 Foot Pedal Adaptor mentioned above is no longer available.

I don't know of any other source of such adaptors, but making one wouldn't be difficult. You'd need a stereo in-line 1/4-inch jack socket and a stereo plug, and the wiring would be :

Socket TIP Plug RING

Socket RING to Plug TIP

Socket SLEEVE to Plug SLEEVE

Alternatively, those who don't want to use a soldering iron could buy two Y-jack adaptor cables and use them in tandem, as suggested in Barry's Mixed reviews:

http://barrysmixedreviews.blogspot.com/2008/09/barrys-mixed-reviews-yamaha -fc7_313.html




Martin

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Martin WalkerModerator
Watcher Of The Skies


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Posts: 17383
Loc: Cornwall, UK
Re: Expression Pedals not generating the full range of MIDI Data new [Re: Martin Walker]
      #818070 - 11/03/10 12:25 AM
UPDATED 10/03/2010 Yamaha's FC7 pedal employs a 50K linear pot (thanks to Matt_Moose for this information), whereas as you can see above, the Roland EV-5 uses a 10K linear pot, which may explain its greater compatibility across keyboards.


Martin

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Martin WalkerModerator
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Ashby Solutions and their FC7 Adaptor are back in business! new [Re: Martin Walker]
      #894826 - 15/02/11 03:40 PM
Good news - Ashby Solutions and their useful FC7 Adaptor have risen from the dead and re-opened their on-line shop for business:

http://music.ashbysolutions.com/



Thanks to Bruce Wahler of AS for letting me know, and apologies for forgetting to post the information until now


Martin

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revoltingrobots



Joined: 07/02/12
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Re: Expression Pedals not generating the full range of MIDI Data new [Re: Martin Walker]
      #968886 - 07/02/12 09:19 PM
hello &
thank you all for helpful information...
with one (main) question remaining for me:

does it mean that it is possible to trim the Lead Foot LFX-1 for usage with a yamaha dx7?
i primarily want to control the master-volume with it.

thanks e lot,
tibor


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Martin WalkerModerator
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Re: Expression Pedals not generating the full range of MIDI Data new [Re: revoltingrobots]
      #969139 - 08/02/12 09:19 PM
Hi tobor, and welcome to the SOS Forums!

Yes, according to the compatibility data above it should be possible to use the Lead Foot LFX-1 to control a Roland DX7.

Fingers crossed!


Martin

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Martin WalkerModerator
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Ashby Solutions FC7 adaptor is back! new [Re: Martin Walker]
      #1034016 - 18/02/13 11:42 PM
Some good news from Bruce Wahler of Ashby Solutions - their FC7 Foot Pedal Adapter has risen from the dead once more! (see photo in above post)

http://music.ashbysolutions.com/misc.htm


1. It converts a Yamaha FC-7 to work with a product that needs a Roland EV-5 or EV-7.
2. It converts a Roland or Fatar pedal to work with a Yamaha keyboard or multi-effect.
3. It swaps the phase of a balanced output to match the polarity of other devices in a large keyboard rig or PA system.

Other useful news from Bruce to add to this thread is:
Clavia (among others) now offers support for both 'polarities' of expression pedal
M-Audio belongs in the Roland camp

Thanks for the update Bruce!


Martin

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Matthew Marichiba



Joined: 29/11/13
Posts: 1
Re: Ashby Solutions FC7 adaptor is back! new [Re: Martin Walker]
      #1076735 - 29/11/13 06:58 AM
Just a suggestion: 1/4" headphone extension cables cost as low as $4 on ebay with free shipping. Buy one, cut it, twist the wires together reversing Tip and Ring, and tape it up with electrical tape. Done in 15 minutes for $4. Wha-bayam!


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Martin WalkerModerator
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Re: Ashby Solutions FC7 adaptor is back! new [Re: Matthew Marichiba]
      #1077329 - 03/12/13 06:36 PM
Yep, that would work just as well Matthew - welcome to the SOS Forums!


Martin

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Martin WalkerModerator
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Re: Expression Pedals not generating the full range of MIDI Data new [Re: Martin Walker]
      #1103758 - 18/05/14 08:05 PM
I've just received a request for clarification about buying particular pedals to use with particular keyboards/synths, but had to admit that I can't categorically state whether one particular keyboard/synth will be fully compatible with a particular foot pedal (at least, not without a lot more comprehensive feedback from users), even if you use the Ashby Solutions adaptor or do a DIY swap of the tip and ring connections to the pedal's jack output socket as described above.

However, if you are considering buying a footpedal for use with a particular device, I can say that:

1. The 'safest' pedal to buy is one like M Audio's EX-P, since this contains a 10k pot and a polarity switch, so that it should work with almost all devices.

2. If you particularly like the build quality of another model such as Yamaha's FC7 that uses a 50k pot, then in conjunction with the Ashby Solutions adaptor (to add your own polarity switch when it's needed) or the DIY tweak detailed above, it SHOULD work with 'most' devices, except those that are known to have issues with 50k pots, such as those from Kurzweil.

3. If you are still uncertain, your safest solution is to Google the name of your particular keyboard/synth device along the lines:

"yoursynthname" AND footpedal OR foot-pedal OR foot pedal

...and see what comments you can find from people who have tried particular combinations and found them to be fully compatible.


Hope this helps!


Martin

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