Vintage Synth Explorer Forums

Hi, I recently obtained a Korg Poly-61 with a midi retrofit. It works good but the keyboard contacts are either dirty or worn out so a good amount of the keys are unresponsive/dead and I don't have the money to have it serviced at the moment or the know how to repair it myself. I have been using a Yamaha keyboard as a midi controller for the poly-61 as a temporary solution. Everything works good but when I try using the Korg's built in arpeggiator in latched mode and use the the midi keyboard controller, every so often it will lock up/go crazy when I hit keys. It seems to do this the most when I try doing chords. When this happens, If i unlatch the arpeggiator, it will continue playing. To make it stop I have to find the keys that are sticking/continuing to play and press them down. It seems to make it stop when I do this. This issue only happens on the Yamaha keyboard/midi controller. Even though some keys are dead on the poly-61, I can still do some chords and stuff on it's keyboard and this never happens. Only with the midi controller. Any Idea what the problem could be??

It sounds like the Korg is not seeing all of the Note Off messages. Two questions: (1) Does your external MIDI controller have a "panic button", or some other way to send an All Notes Off message? If so, does that straighten out the arpeggiator when you send it? (2) If you turn off the Korg's arpeggiator, can you play chords reliably from the controller, without stuck notes?

I just thought of something else... you say you are using a Yamaha keyboard as a controller. Which one? Some old Yamaha gear does note-off by sending Note On messages with a velocity of 0. Although the MIDI standard permits this, a lot of older gear didn't implement it properly.

Who did the retrofit? There are a few of them, along with the official Korg one.

cornutt wrote:It sounds like the Korg is not seeing all of the Note Off messages. Two questions: (1) Does your external MIDI controller have a "panic button", or some other way to send an All Notes Off message? If so, does that straighten out the arpeggiator when you send it? (2) If you turn off the Korg's arpeggiator, can you play chords reliably from the controller, without stuck notes?

To answer the first question no, it has no panic button. The Yamaha is a cheap one. It's model number is ypt-230. I'm not sure how old it is though. It only has 5 pin midi in/outs. No usb. I guess it can't be that new then. To answer the second question, Yes it works fine that way. Even the arpeggiator works right if I keep latch mode off. It's when I turn the latch on so I dont have to keep holding down the keys to continue the arpeggio loop does it happen. I will try to play another chord and it seems that if I change chords too fast it sets off other notes that I didn't press and then they wont stop playing on the arpeggiator until I unlatch it + press down the keys that started playing randomly to make all the notes stop.

Jabberwalky wrote:Who did the retrofit? There are a few of them, along with the official Korg one.

It came with a certificate that said it was retrofitted by a tech licensed by Korg sometime in 1986

Very strange problem. I know P61s pretty well, but don't have Midi on mine. Perhaps it's getting mixed signals from some dirty key contacts.

Jabberwalky wrote:Very strange problem. I know P61s pretty well, but don't have Midi on mine. Perhaps it's getting mixed signals from some dirty key contacts.

That could be possible. It's strange though that it only does it when it's latched.