[sdiy] Hacking the expression pedal input on a JD-800

[phillip m gallo]

David,

Here's a ref for a EV-5 schem.

http://www.geocities.com/phillipmgallo/ev-5-schematics.gif

regards,
p


-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of WeAreAs1 at aol.com
Sent: Thursday, February 19, 2004 11:10 AM
To: david.k.cornutt at boeing.com; synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Hacking the expression pedal input on a JD-800



In a message dated 2/19/04 10:58:27 AM, david.k.cornutt at boeing.com
writes:

<< So the question is: has anyone opened up a Roland 

expression pedal?  Does it consist of just a pot, or is

there active circuitry in it? >>

Hello David,

The Roland EV-5 pedal is simply a pot that's wired directly to the three

terminals of the 1/4" TRS plug (there's second pot that's also in there
to set the 
"minimum value", but it can be eliminated for your purpose).  I don't
have 
the schematic handy, but a 50K pot value seems to come to mind.  I'm
pretty sure 
the pot has custom taper that's designed to match the throw of the pedal
(the 
EV-5 still has a terrible feel, though).  I'll look around and see if I
can 
find the schematic.

Michael Bacich