Roland D-50 Sustain Pedal Jack problem

[thepkdmt]

I have a vintage Roland D-50, I am not a keyboard player, I bought this a while back to use on some recordings and for something to play with.

When you play the keyboard, the sustain is constantly on and on all patches without any pedal plugged in.

If you plug a 1/4" jack into the pedal jack, the sustain ends when you close the contacts. I have read that Roland keyboards (or at least the older ones) have a normally closed switch for this control... so what I am wanting to find out for sure is:

1) Is this true, that the sustain circuit is normally a closed circuit and requires a pedal that is normally closed?

2) Is there some master setting or menu option where this can be changed?

3) Does this mean the jack is broken or the keyboard as some problem since it sustains without any pedal plugged in?

Any help would be greatly appreciated. I have the user manuals and the service manual for this unit...

Thanks for any help,

-Kyle

[rhino]

Welcome to the board.

1) Try plugging in the pedal BEFORE you power-on the synth. Many synths automaticaly sense the pedal polarity.

2) If still no joy, suspect the the jack where the pedal plugs in is damaged inside.

[cornutt]

1) Is this true, that the sustain circuit is normally a closed circuit and requires a pedal that is normally closed?

It's true; older Rolands are notorious for this. The jack is a normalling-type jack that is supposed to short itself when nothing is plugged in. If the normalling function of the jack isn't working, you get forever sustain with nothing plugged in.

You might be able to fix it by opening the unit and spraying the contact points in the jack with contact cleaner. If you have it open and you plug and unplug the sustain pedal, it will be obvious which part of the jack performs the normalling function; you might be able to clean that up with contact cleaner. If that doesn't work, replace the jack.