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Korg DSS-1 help

2016-04-22 by nuwavboy@...

Hello! I have a DSS-1 that I bought years ago as a parts machine, it's been in storage and I just recently took it out and was pleasantly surprised to find that it fires up!

I'm having a problem in that every 8th note is not sounding - I also hookedup the midi out and it's also not sounding on the out - so I'm assuming it's the keybed, not the actual voice itself. Is there something to look for? I took the keybed apart as it was crazy filthy, pulled all the keys to clean em. I havent put it back together yet as I'm thinking I'll just install a new(used) keybed from Syntaur.

Thoughts? Excited to get this one up and running!

tom

Re: Korg DSS-1 help

2016-04-23 by rpcfender@...

This message is from bobgrieb <bobgrieb@...>

Sorry Bob. Your message is still filled with that formatting stuff.

Royce

The DSS-1 has 8 voices, so it's possible that one is not working. That could also cause every 8th note to not sound. If it's certain keys that are not working, then that is one thing. But if it's every 8th note, regardless of which keys are causing them to play, that's a voice issue. I see you are not getting MIDI out either. Hadn't noticed that. So I guess it is not a bad voice. I grabbed the service manual from the web. On pdf page 14, you can see three connectors for the keyboard. Two are driving the contacts (a pair for each key) and one is sensing. Before you replace the keyboard, you might want to do a little troubleshooting to make sure it isn't one of the three chips instead. Looks like IC5,6,7. You should be able to use jumpers instead of the keyboard and play notes. The keyboard is just a bunch of switches. Use jumpers with series diodes as well to mimic the keyboard circuit. Probably the DSS-1 code expects the first contact to close, then the second one. That would mean a jumper from one pin of connector 24, such as 24-1 to one pin of 23. Put a diode in series with the jumper, with the anode towards connector 23. Then after you have made that connection (and are keeping it made) place a second jumper from the same pin of connector 25, such as 25-1 to the same pin of connector 23. At this point a note should play. Actually, it might be best to connect the two diode cathodes to connectors 24 and 25 first. Then connect the anodes together and hook them both to the pin of connector 23 at the same time. That would simulate a fast key press, unlike connecting them one at a time. That should make the note louder if velocity is enabled. By connecting the anodes to each of the 8 pins on connector 23 in turn you can see if all 8 inputs are working. Likewise, by moving the other ends of the jumpers to 24-1 and 25-1, then 24-2 and 25-2, etc, you can see if all 8 of the driving circuits are working. If one signal is out, then every 8th key will not play. Of course, it could also be a trace on the keyboard pcb itself that has corroded through because someone spilled something years ago. That's pretty common. If you know which keys are out, then use an ohmmeter in the diode position to check continuity (through the diodes) from the key contacts back to whatever connector is on the keyboard, or wherever the cable hooks to it. The polarity has to be correct on the meter leads of course, to forward bias the diode. Hope that helps.

Re: Korg DSS-1 help

2016-04-23 by nuwavboy@...

It definitely is something in the keybed itself I believe. I've ordered one from Syntaur for 40$, figure its cheap enough to start like that. Thanks for the info!

Also, having a brain fart of a moment. I took all the keys out, and to reinstall I know I have to start with the black keys, but can not figure out how the springs go back in. Does anyone have any advice, pictures etc?

tom

Re: Korg DSS-1 help

2016-04-27 by nuwavboy@...

Update - bought a new (used) keyswitch board from Syntaur and it fixed the problem of every 8th note not triggering. A couple keys were broken, so it obviously took a hit at some point and probably broken a trace or connection somewhere in that board. 40$ well spent.

Has anyone installed one of the cheap floppy emulators into the DSS-1?

The 25$ ones on ebay?

tom