{"id":8157,"date":"2006-04-04T23:28:00","date_gmt":"2006-04-05T03:28:00","guid":{"rendered":"https:\/\/nuxx.net\/blog\/2006\/04\/04\/casio-sk-1-midi-modification\/"},"modified":"2026-07-01T11:34:22","modified_gmt":"2026-07-01T15:34:22","slug":"casio-sk-1-midi-modification","status":"publish","type":"post","link":"https:\/\/nuxx.net\/blog\/2006\/04\/04\/casio-sk-1-midi-modification\/","title":{"rendered":"Casio SK-1 MIDI Modification"},"content":{"rendered":"

<\/a>
Casio SK-1 MIDI Modification PCB and my opened SK-1.
(Click for more…)<\/center><\/p>\n

Well, I’ve started the Casio SK-1 MIDI Modification project (photo gallery retired)<\/em>. That is, the one which will add a MIDI input to my SK-1. Since the SK-1 has a rudimentary sampler and the nifty ‘human voice’ patch, along with the fun-to-play-with ‘synthesizing’ section (must remember to read up on this), it could be nice to trigger it remotely.<\/p>\n

I’d imagine such a thing would also be useful to anyone with a bent or modified SK-1 (or SK-5, for that matter) too, since those are more likely to be used in a stage-type environment where remotely triggering with patterns would be useful.<\/p>\n

Anyway, after making the PCB<\/a> (and here<\/a>) on Friday I went ahead and opened up the SK-1<\/a> to see how much room I’ll have to work with<\/a>. While in there I also decided to strip the top panel and give it and all keys and buttons a good cleaning<\/a>. It actually came apart fairly easily.<\/p>\n

I did run into two problems, though. First, the PCB I made had couple small gaps in some traces where I had inadvertently scratched the photoresist before etching<\/a>, but those were easily fixed with a wee bit of solder<\/a>. Secondly, those spots in the tin plating are because I put the board in the plating bath before its precipitate had finished re-dissolving, and I think places where solid chemical sat against the board, those marks were left. Fortunately no pads are affected.<\/p>\n

Now I’m just waiting for the set of solid carbide drill bits from eBay<\/a> which I’ll be using to drill the part holes and vias in the PCB. Oh, and my order from Digi-Key for all the components I didn’t already have. I actually ordered enough parts for two of the adapters. Maybe I’ll etch a second board and make one to sell, if I find someone who wants one.<\/p>\n

I received the pre-programmed 2732A ROM<\/a> from Paul Messick<\/a> yesterday, so I now have the software (yes, 20 year old software!) for running everything. Hopefully by next weekend I’ll have the rest of the needed parts and I can get going on finishing it all up.<\/p>\n

One thing I forgot to order from Digi-Key was an Atmel AVR Butterfly<\/a> so I could play with programming the ATmega169. It’s only $20, so it makes for a good experiment, even if I don’t end up using the controllers in anything. Ah well, one project at a time.<\/p>\n

That reminds me… I also ordered some 20\u2126 wire-wound pots from Mouser (along with a breadboard and other unrelated stuffs) to wire in series with the Bourns 10-turn pots<\/a> I had previously installed in my Elenco XP-720K (photo gallery retired)<\/em>. While the 10-turns are quite precise, I was having a difficult time nailing thousandths of a volt precision. It was possible, but took some very careful nudging of the knobs.<\/p>\n

So, figuring that I have 2K\u2126 10-turn pots, one full turn is about 200\u2126. That means that the 20\u2126 ones should add about 10x the resolution, allowing me to hit whatever voltage I want. (I say ‘about’ because a ‘full turn’ is only 300\u00b0 on a single turn pot whereas it is 360\u00b0 on the 10-turn ones.) I’m still not completely certain where I will mount them, but for now I think they will probably be fit one above each other between the two current pots<\/a> with the top one being for the left pot, etc.<\/p>\n

Hmm, yeah. That was a lot of babbling about electronics. Don’t worry, I’m done.<\/p>\n","protected":false},"excerpt":{"rendered":"

Casio SK-1 MIDI Modification PCB and my opened SK-1.(Click for more…) Well, I’ve started the Casio SK-1 MIDI Modification project (photo gallery retired). That is, the one which will add a MIDI input to my SK-1. Since the SK-1 has a rudimentary sampler and the nifty ‘human voice’ patch, along with the fun-to-play-with ‘synthesizing’ section\u2026<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,11,34],"tags":[],"class_list":["post-8157","post","type-post","status-publish","format-standard","hentry","category-electronics","category-making-things","category-moved-from-livejournal"],"_links":{"self":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/8157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/comments?post=8157"}],"version-history":[{"count":1,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/8157\/revisions"}],"predecessor-version":[{"id":13472,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/8157\/revisions\/13472"}],"wp:attachment":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/media?parent=8157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/categories?post=8157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/tags?post=8157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}