Sequencing Yamaha CS-40M from Elektron Analog Keys/4

January 1, 2018

I managed to get the CS-40M controlled and sequenced by the Elektron Analog Keys (AK) and tracking over a useful 5 or 6 octaves today.  This was a bit of a challenge as I could not find any information on the internet about how to setup the AK to do this.  Sometimes with older synth’s it is hard to find information on how exactly to get them working with modern synths.  This info should help with the entire line of CS synths, but I have only tried with this CS-40M so, YMMV.  Also, before you start this, it is a good idea to ensure that your CS is calibrated and tracking across it’s keyboard range properly.  This will not fix a synth that is in need of calibration!  One other thing, all older synths age differently.  Settings that you need to use may be slightly different than those from the manual, and again slightly different from mine.

This process should also work for the Elektron Analog 4 (original and MkII)!

That’s it for the caveats – let’s get started!

The key to success can be found in the service manual (Google is your friend).  If you look on Page 33 you will find a tuning chart that lists output control voltages. As these are designed to control another CS, it stands to reason they should correspond to the input voltages, and as it turns out they do!


There are two CV inputs on the CS-40 and in order to get everything pitching correctly I connected CV’s A&B from the AK to these to control pitch.

In the AK CV settings, setup CV A & B for Pitch Hz/V set note 1 to F2 at 0.169 (the chart says 166.8 but my CS was only close with that so I fine tuned). I set Note 2 per the manual as C5 at 1.000. These settings worked well but I found the range to be more “normal from an AK perspective if I set the notes to F1 & C4 respectively.  Try it and set yours up whichever way you like.  I also had to go to the tuning page for CV A & B on the AK (from the screen pictured below just press the “No” button once) and making some adjustment there.  I also ended up making very minor adjustments to the VCO tuning on the CS to perfect it.  I probably could have just done that part right on the CS.



There are also 2 trigger inputs on the CS-40 so I connected CV’s C&D from the AK as triggers (Gate, S-Trig, 5V).  This was way easier to setup and no fine tuning was required!

Other Inputs

Unfortunately, I have now used up all of the CV outputs on the AK and I won’t be able to control the VCF (Voltage Controlled Filter) or the VCA (Voltage Controlled Amplifier)… but if I can find or create a couple of 1/4″ stackable cables or a basic mult we should be in business and I will be able to use the P-Locks from the AK for the filter and send envelopes from the AK too!