Re: expression pedal with all access

[jim palmer <jimp@pobox.com>]

i don't have the 251, but i have several moogerfooger pedals and i'm sure 
it 
works the same way.  moog made the control inputs so they could take 
either a trs expression pedal in or a mono cv input. it's a pretty clever 
idea,
he feeds a 5v source to the ring, which is shorted to ground when a mono 
cable is
inserted. it's current limited so nothing fries when this happens.
the expression pedal acts as a voltage divider so you get a 0-5v signal at 
the tip.

so you connect the ring to the high side of the pot
(this will be the tip of the input on the eb pedal)
the sleeve goes to the sleeve of either jack on the eb.
the tip goes to the tip of the output of the eb pedal.
you can use a standard insert cable or rewire the eb with a trs jack.

this is not the way most trs expression pedal inputs are wired.
for example the rocktron all-access has the tip and ring switched.
but then, it can't take a mono cv input...

----- Original Message ----- 
From: "Reid, Benjamin" <BReid@about-inc.com>
To: <Loopers-Delight@loopers-delight.com>
Sent: Tuesday, May 21, 2002 8:42 AM
Subject: RE: expression pedal with all access


> sorry to exhume thread but I got a new piece of gear and i'm a bit 
>confused.
> 
> I got the CP-251, which is a control voltage mixer/controller. It 
>references
> it's own expression pedal which has a single line out of the thing. Does
> anyone have experience with this and can they offer a suggestion on 
>whether
> I need to buy this or can jerry-rig something else?
> 
> My guess is that it's just a TRS line which could be duplicated through 
>my
> Ernie Ball mono pedal using a TRS breakout cable. Anyone know if this is
> true? I am reluctant to experiment with the thing and short it out by
> accident. Log range is OK.
> 
> Thanks in advance,
> 
> Ben
> 
> PS my application is controlling the Sherman which I monkey'd with last
> night and it is just wicked. But I'd like to get a VCO kit too...
> 
> -----Original Message-----
> From: jim palmer [mailto:jimp@pobox.com]
> Sent: Monday, May 13, 2002 6:51 PM
> To: Loopers-Delight@loopers-delight.com
> Subject: Re: expression pedal with all access
> 
> 
> you can use the ernie ball as-is with a standard insert cable, but you 
> get a log curve - the middle position of the pedal does not 
> translate to the middle of the control range.
> in other words: if you set your control range to 0-127 (default),
> the middle pos of the pedal will not result in a cc of 64...
> in order to get this behavior, you have to replace the audio taper
> pot with a linear taper pot...
> 
> > i think the ernie ball mono pedal will work fine....although i'm told 
>i'll
> > have to build a special cable for it...we'll see.
> > 
> > -jim
> > 
> > 
>