Hall effect CV pedals (was: Volume pedals for CV discussion)

[WeAreAs1 at aol.com]

Roland made a few pedals that used Hall Effect sensors, back in the late 
70's/early 80's.  They were the "Rocker" pedals.  I guess they'd have to be 
"Alternative Rocker" pedals, or "Post-Punk Rocker" pedals if they made them 
now.  I never got a chance to try one out, so I don't know how well they 
worked.  As John Blacet may have pointed out, unpredictable linearity, 
temperature response, and part-to-part variations may be mitigating factors 
in the practicality of these devices.  I may have a schematic diagram for the 
Rocker Wah around here somewhere.  I'll have a look and get back to the list 
about it.

Michael Bacich

In a message dated 4/6/99 12:27:39 PM, you wrote:

<<Have any of you ever tried to use a Hall effect device instead of a
potentiometer or LDR? A magnet can be glued to the underside of the pedal,
and as it is depressed, the magnet is brought closer to the Hall eff
device. The closer it is, the stronger the magnetic field is, and thus the
output voltage.>>