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Re: Vortex Now (expression pedals)

At 08:51 PM 10/26/98 -0500, you wrote:
>On Mon, 26 Oct 1998, Joe Cavaleri wrote:
>> jeff , there is no difference between the two. 
>> I think what Roland was referring to is a voltage control pedal such as 
>> roland EV5. I think that's the one I use. "That is of course unless you
>> using a control voltage to control a volume parameter!"
>Just a heads up to those of you looking for the fabled EV5.  I looked and
>looked for one when I got a hold of my Vortex, but with no luck.  Perhaps
>Roland has stopped producing this pedal?  In any case, I picked up their 
>FV5 and it works as well (just need a different cable).
>My only complaint is that the FV5's response curve is odd (almost
>parabolic?).  It's VERY responsive in the first 20% of the pedal swing,
>then it cools out to give a flatter curve.  Do any of you folk know how I
>can flatten out the curve to get a more uniform response through the
>pedal swing?  As it is now, the first 20-30% of pedal swing takes my
>Vortex from 1-50 with the last 70-80% of the swing taking me up to 64.
>Is this behavior standard in E/FV pedals or is mine just whacky?

That is standard for a volume pedal. That's because volume is best
controlled with "log taper" potentiometers, where the resistance through 
pot changes in a logarithmic fashion. (for your ears, this sounds like a
smooth increase in sound as you move through the range.)

Expression pedals usually use a linear taper pot, where the resistance
changes linearly through the range. 

When you use one in place of the other, you get the sort of experience you
are having. Most of the change occurs in a very small range of the pot.

If you are willing to do a little soldering, change the potentiometer in 
pedal to something like a 20k linear taper pot. They should be easy to 

Kim Flint, MTS                 408-752-9284
Chromatic Research             kflint@chromatic.com