Thanks for the information guys. I will be getting an FC-7.
I really appreciate your help!
John Broaddus
--- In motm@y..., WeAreAs1@a... wrote:
>
> In a message dated 2/7/02 9:49:12 PM, motm@y... writes:
>
> << "corelli44" <john@p...> wrote:
>
>
> Hello List,
>
>
> I have an old Volume/Modulation pedal that I got with my original
DX7
>
> back in 1985. I'm trying to measure the resistance to see how to
use
>
> it with the pedal interface but I'm not getting very clear numbers.
>
>
> I get readings between 25 and 40 most of the time with the pedal up
>
> or down. It does go up to as high as 150 sometimes but very briefly
>
> (could this be my DVM? It's quite cheap).
>
>
> Also, I only get readings with leads on the very tip and behind the
>
> first ring on the plug. I get nothing with one of the leads between
>
> the two rings (and the other on either side of either ring). Is
this
>
> the way the newer Yamaha pedals are wired?
>
>
> I'm just wondering if older pedals might have been made a bit
>
> differently than the newer Yamaha pedals or if they should be
>
> somewhat similar (if anyone has any experience with older pedals).
>
> >>
>
> The foot pedal you have is a model FC4. The pedal they are
currently making
> is the FC-7. The old FC-4 is an opto-electric pedal. It contains
a small
> incandescent light bulb and a photoresistor. Two of the TRS plug
conductors
> are connected to the photoresistor; the other conductor supplies DC
voltage
> to the light bulb. Movement of the pedal opens and closes a small
shutter
> between the bulb and the sensor, allowing in or shutting out the
light from
> the bulb. With no power applied to the lightbulb, moving the pedal
(opening
> and closing the window) won't really change the measured value of
the
> photoresistor (it's dark in there!). This is in contrast with the
newer
> "passive" FC-7 pedals, which are potentiometer-based, so their
resistance can
> be varied with no power connected.
>
> For more reasons than one, it's probably a better idea for you to
try to
> obtain one of the newer pedals for use with your analog equipment.
>
> Michael Bacich