This solution works 100% on sp 280 and sp 170. I guess it works anywhere a pu 2 triple pedal goes.
Tried to find relevant info online, but since i couldn’t find anything, i studied the service manual of sp 170 and came with a simple diy approach.
First of all, the pu 2 is connected with a male 4 pin NPP connector on the piano. These connectors come with extra male crimps.So you need at lest one connector and at least 4 pins. I say at least because they are super cheap (under a euro all together) and they can be damged during construction if you haven’t used them before. No need for more than another set.
You also need to know or understand how such crimps are attached to the cable.
It’s not a task for first timers since good contact and good alignment of the thin pins is of vital importance. I mean the cable will not work at all. Or it will be really bad and will betray you when it shouldn’t.
If you can’t trust your cable construction skills, just buy a ready made spare pu 2 cable. Easier, sturdier but more expensive. Just use the connector that goes to the piano and cut the other side.
The connector is connected only one way on the piano.
The first pin towards the bass notes side (can be left or right depending on point of view) is the common ground. Common that goes to each pedal that will be used.
The second is the damper pedal.
The third is the sostenuto.
The forth is the soft.
So just take the cables attached to the 4 pins (if you want three pedals attach three cables on the ground pin, if you want two, just two).
If you want you can only use it for sostenuto or soft and connect the damper from the jack. The jack is connected internally to the line of pins.
Keep always in mind that whatever single pedal (with korg piano polarity - they all have the same) has to have the ground sent to pin one (the one towards the bass notes) of the connector.
Use a splitter box with female jacks, a female jack on the end of the cables, or even the pedal directly on the connector (i wouldn’t advise it because it can play a bit with the connector’s stability.
I repeat and repeat…Keep an eye on the correct alignment of the pins in the connector and make them as firm and stable as possible.
If you know what you ‘re doing, you ‘ve tested the construction properly, and sometimes you feel that the effect comes and goes (check it properly once more if you can with midi monitor like midi ox etc)the problem lies on the pins stability.
Not very hard for most intermediate cable builders and really easy for experienced diy-ers.
For the extra special second step and a great half damp approach pedal read this great article and mix and match.
https://peter-repin.livejournal.com/98934.html
Hope it might be helpful to someone