MIDI control for standard 1/4" expression pedals.

[willhaven]

So, I'm getting a MIDI floorboard (Rocktron All Access LTD) and a couple of audio switchers (2x Voodoo Lab GCX units). I know that the expression pedal input on the Rocktron (1/4" plug) gets converted into MIDI and can be sent along the MIDI cable to your rack, but I don't know if I can make use of this without a MIDI input on my effect pedals.

 

My Dunlop UniVibe, Mesa Revolver (leslie speaker cabinet), and a couple of pedals I'd LIKE to get use 1/4" remotes for expression.

 

Is there some sort of device that can interpret MIDI signals and convert them into the proper resistance and output in a standard 1/4" cable for real time remote control of non-MIDI pedals?

[NITEFLY182]

Not that I know of. Midi control pedals are often used with rack units.

[enditol]

Check out http://www.midisolutions.com/ they have things like that.

[willhaven]

Thanks for that site. Their products look promising! I'll have to delve into the manuals to see if it can really do what I need, however.

 

Anybody else know of anything?

[slight-return]

but I don't know if I can make use of this without a MIDI input on my effect pedals.

 

 

Well, obviously not DIRECTLY, you'll need some conversion

 

 

Is there some sort of device that can interpret MIDI signals and convert them into the proper resistance and output in a standard 1/4" cable for real time remote control of non-MIDI pedals?

 

 

It can depend, expression control is FAR fom standardized, so just 1/4" expression jack isn't enough of a spec

 

for instnce, the moog stuff can be run as CV input (when you plug an expression pedal into em the unit is feeding the supply voltage to the expression pedal, so it can be read as a CV)

 

so a MIDI to CV convertor (like the Doepfer MCV4) could do this by changing the midi cc values (the part of MIDI that acts like "expression" controllers) into actual CV out

 

you are often going to find these sorts of products associated with old-school analog/modular synths

 

 

Other mnufacturers that are using different systems in expression control (like where the expression pot is modifying an RC network for timing control, etc) will probably need more conditioning (like having a CV drive an optoisolator to mimic the actual resistance) and may be getting to the limits of practicality, esp if you arent into brewing your own

 

I think the first thing to do would be to find out the specs on the expression control INPUTs and work from there

[willhaven]

I'm not using anything wild like an EH Memory Man/HOG/2880 CV controller yet. Just simple expression pedals. I know they can have different pot values, but I would assume a flexible unit could cover most ranges of resistance to make almost anything function properly.

 

It looks like this unit here may do all I want and more. I found it linked from the MIDI Solutions website. None of their products seemed to do what I'd need.

 

Oooooo... aaaaaahhhhhh...

http://www.kentonuk.com/digital_interfaces_converters/midi_cv_converters_extras/pro2000.html

[slight-return]

I'm not using anything wild like an EH Memory Man/HOG/2880 CV controller yet.

 

 

that gen of EHX foot controllers aren't CV

 

 

Just simple expression pedals. I know they can have different pot values, but I would assume a flexible unit could cover most ranges of resistance to make almost anything function properly.

 

could be a dangerous assumption - I'm only seeing CV in their little "features" list, not resistor control. Resistor control can be a lot more all-over the place (even the "pinout" on the jack isn't standardized)

[willhaven]

So, what do the EHX foot controllers use?

[slight-return]

apparently logic pulses from the microcontroller in the control pedal (I don't know the format of if it's simple 2-state serial or some n-state)

I'm under the impression the communication is bidirectional as well
(I had some techn questions last year and thy were VERY responsive, had me chat with one of the technical guys)

[MegaTom]

what you want. I'm stoked!

Moog?

[Jumbo Fuzz]

Moog?

 

 

That is what I was wondering. This could be very interesting and I will be following this thread closely. The ability to control multiple Moogerfoogers and all of their expression parameters (in addition other pedals with expression pedal capability) would be very interesting.

 

I was thinking about this just a week ago, great thread.

[MegaTom]

Moog?

 

 

http://www.moogmusic.com/detail.php?main_product_id=21107

[SpectralJulian]

Moog pedals and some other pedals use CV, so a midi to CV converter would work. But for pedals that use resistance instead of CV, you could probably make a CV to resistance converter, using a photocoupler.

[willhaven]

This is the closest I've found... but it would be a DIY project at the very least. It also seems to top out at a resistance of 100K.

 

Ideally I'd like to be able to program my Rocktron All Access to send values to set the resistance value (like setting a preset on a wah or Leslie rotation speed) in addition to acting as a foot controller with a variable max resistance (to accommodate different designs).

 

Anybody know off hand the typical resistance values used with most expression pedals?

 

http://highlyliquid.com/kits/mpa/

[boogieman_dan]

 

Anybody know off hand the typical resistance values used with most expression pedals?

 

 

Generally, 50k? or less. I use a 25k? with my G-Force and it works very well.

[SpectralJulian]

But not all pedals work on resistance for expression dude. Some of them work on voltage. You want to be able to do both, and have intimate knowledge of each pedal's expression requirements.