<!-- from fixya rte -->M audio sustain pedal scematic - M-Audio SP2 Piano style sustain pedal

No you can't as our PROPER Expert Cindy says.

Casio Ct-636 does not support any sustain pedals.Amazon.comhttps://www.amazon.com > ask > questions
A: Casio Ct-636 does not support any sustain pedals.

The other 'Contributor' probably saw this

CT-S1000V - SupportCasio https://support.casio.com > manualPDF

This Digital Keyboard does not come with a pedal unit. • You can use the PEDAL1 jack to connect an optional (SP-3, SP-20) sustain pedal. You can use the.

I would suspect the sustain pedal jack on the keyboard is either dirty or defective. Try using some contact cleaner first, and if that doesn't work replace the jack.

Sorry, but the Yamaha pedal has the opposite sense (it is a normally open contact) than what is REQUIRED by Roland equipment. Roland requires a Normally Closed contact. Unfortunately, one is confused because the Roland jack for the sustain shorts itself to no sustain when you unplug a pedal. SOMETIMES one can open a pedal and with soldering iron change a wire to reverse the pedal sense IF the particular pedal has both contacts available.

This is confusing... you say "the sustain works when you disconnect the cord"? How can that happen? and doesn't work when it is plugged in.

MOST sustain pedal problems are due to people using a different pedal than the keyboard is designed to use. It is very common that someone tries to use a Roland sustain pedal on a Yamaha and oof course it doesn't work because the Roland pedal is normally closed and Yamaha usually requires a normally open contact.

A FEW keyboards now check the state of the pedal input when power is first turned on and configure the pedal polarity accordingly. For these keyboards, make sure the pedal is plugged in before power is turned on.

No it does not have a sustain pedal input an there is no way to add one, sorry.

Make sure you are plugging it into the place for the sustain pedal. If you happen to plug it into the audio out it may kill the sound.

The sustain pedals have only two wires. Usually they terminate in a 1/4 inch mono plug.

yamaha USUALLY sustains when switch is closed. Roland usually sustains on a switch between the wires when the switch is open.

NO POWER should be supplied BY the sustain pedal... it is ONLY a switch.

I have the same problem, But I have been using the same pedal since new. Infact it came with this pedal. Then suddenly it started doing this. Could I have changed soem setting by accident?

I found that if I plug in the sustain pedal BEFORE turning the power on, it works fine. If I plug in the sustain pedal AFTER turning the power on, then it works in the opposite way. Probably just the design. So I would try playing with that before doing anything drastic.

Not if its like mine, its a completecircuit vs.incomplete circuit problems.

I had the exact same problem with my Casio keyboard and a Yamaha sustain pedal I bought.

I'm not an electrical genius, but I was able to get it to work by opening it up and doing a little modification. Of course I first just tried switching the white wire with the black one but that didn't change anything at all when I tried it. It turns out the Casio wants the circuit completed to sustain, and broken for no sustain, which is the opposite of what the Yamaha pedal does.

I opened it up and mine had three three flat metal strips let's call them Top, Middle and Bottom. The Middle and Bottom ones were joined together on the right side, and the Middle and Top ones were touching on the left side when the pedal was not pressed. These seperated when the pedal was pressed, thereby breaking the circuit because the wires were on the top plate and on the joined Middle/Bottom plate.

So to flip it I:
1. Unsoldered the Bottom wire
2. Cut apart the Bottom and Middle plates on the right.
3. Bent the Middle plate on the right to touch the Top plate instead and soldered those together.
4. Soldered the Bottom wire back on.

That's it! Once I figured it out, it took only a few minutes to fix.
Good luck!
Paul