Want to bend an SK-1? This might give you some ideas

Some time ago… well actually ages ago I built this thing here:


And since everybody kept asking me to share schematics and stuff, I’ve put everything together into a nice PDF so people could try and do the same (hopefully better).

If you’re into this type of thing, you can check the pre-release version here. I’m fixing the last “bugs” in the text and will soon release the final version together with some CAD files for the panel, in case somebody needs a starting point.

Download PDF here:

If you have errors to report or there’s things you don’t understand, please let me know!

Nice work Hannes!

And well done for documenting everything for the benefit of others - I know how long that can take.


Hehe, yes it took some time, but if people do something great with it, it’s going to be worth it!

Final version is online! Also I’ve added the CAD files for the front panel and some info on the case design in general.


Please refer to this page for future updates.

Dear Hannes, thanks a lot! This is a bunch of useful information - and it looks good, too :slight_smile:

There must be a second (rather beat-up) SK1 “somewhere” in a box “somewhere” in my cellar … The main SK1 I have is from a guy I went to school with. He got it as a present from his Grandmother back in 1985 or '86 when they hit the german market. Its boxed, still with the original manual, in good shape + it has a personal history to it. I can remember us burping and farting into the mic and play it back on reverse :wink: To me, this is a collectors item I would never even dare to mod. I also used it a lot for ambient/soundscapes I made in the late 1990s.

But the second one I have is in a poor shape. I bought it at a flea market for 1 or 2 Euro, it looks bad but works perfectly. This one I always wanted to mod/bend some years ago. Now I’ll just need to find it again. But I know IT IS there, “somewhere”.

Thanks for reminding me.

If I had an SK-1 like yours with memories attached to it, I wouldn’t try to mod it either. Actually even less is enough. We have a mint VL-1 with the original pouch and a working display (a rarity) here and even if it hasn’t much emotional value I wouldn’t dare to bend it. It’s also my wife’s and she would kill me if I tried any bending on it… but the point is still valid I guess :slight_smile:
Anyway, glad if this can be of inspiration/help or just a reminder to do a project that was sitting in the drawer for some time.

I have a similar story to to my SK-1. I got it for my 11th birthday or maybe it was ‘Sinterklaas’ probably in '86. I think it might have been the reason for me to get into music and synths. But i was interested in these things obviously then already.
I used it a lot in a music group i was in in the early 90ies. We drove it thru a wahwah pedal and a boss delay and it was our only ‘synthesizer’. The other sounds came from a AKAI S01 sequenced by an Alesis SR-16. We recorded a new track almost every evening. I’ve got about a dozen 90 minutes cassette tapes full of stuff we did in those years.

My first “synth” was a Casiotone CT-380… unfortunately a rather boring one compared to the SK-1… but I really regret giving it away now…