Re: [AH] Wiring standard for synth expression pedals?

From sam
Sent Mon, Dec 10th 2018, 03:41

First of all, there are active pedals and passive pedals, and they are =
all called expression, CV, or other names.  The active pedals PRODUCE =
their own voltage (so they must be powered), and these are for use with =
vintage synths.

More current products (90s for sure, maybe earlier) use passive =
expression pedals, where the pedal takes a voltage generated by the =
keyboard, and then doles it out back to the keyboard in the appropriate =
amount (depending on the position of the pedal).  An active pedal will =
have a phone plug with two connectors (TS, voltage and ground), while a =
passive pedal will have a 3-conductor (TRS) phone jack - one for =
incoming voltage, one for voltage back to the synth, and one for ground.

The Ensoniq pedal is passive, and there are definitely two flavors of =
passive pedals.  If I recall correctly, one uses a linear pot, and the =
other uses an audio-taper pot.  I remember once on the road some of our =
gear got stolen, and I had to use a Yamaha expression pedal with my =
Ensoniq boards.  All the =E2=80=98business=E2=80=99 of the pedal =
happened in just a few degrees of travel of the pedal.  So while you =
will get results using the wrong type of pedal, they won=E2=80=99t be =
usable in a practical situation.

I have not, though run into a situation where the pedal is wired =
differently=E2=80=A6

Sam Mims
Syntaur



> On Dec 9, 2018, at 4:22 AM, Thomas Strathmann <xxxxxx@xxxx.xxx> wrote:
>=20
> On 09.12.18 08:24, Brian Willoughby wrote:
>> I just ran into a situation where my Ensoniq Expression Pedal is not =
compatible with a new USB-MIDI controller. Is there one standard for =
wiring a passive expression pedal, or is there more than one?
>=20
> Yes. My expression pedal has a switch to select different =
configurations. It's the same mess as with sustain pedals.
>=20
>         Thomas