Cv/gate sequencing ms20



Anyone knows why i cant use the keys (transpose) on the ms20mini while cv/gate sequencing from A4?

I also sequence a sub phatty the same way and i can play the keys while the sequence is running.

Unable to track audio from ms-20 to analog 4 MK2 via cv function

When you control your MS-20’s pitch via the CV input on the right side of the patch panel (next to the TRIG input), you break the connection between the keyboard and the pitch. You essentially use your sequencer as a replacement for the keyboard, and therefore the keyboard doesn’t have any effect.

However, that’s not a problem! The trick is using the osc modulation input (top left corner of the patch bay) for controlling pitch instead of the dedicated CV in. Now the keyboard controls the base pitch and the sequencer just offsets it from this. Note that you’ll need to adjust the pitch modulation knob to get the range correct (mine’s fine somewhere around 8 if I remember correctly), and AFAIK the A4 should send pitch as 1V/Oct instead of Hz/V.

I’m pretty much always using this method when I’m sequencing the MS-20, though you do lose that modulation input so it’s not always possible.


That’s clever !


Thanks Low Life, ill try this asap. Ill report back to you and let you know how it works.


By the way, when you’re setting up CV for this, it probably makes sense to set it so that middle C is at 0V since you’re sending offsets. Now sequencing middle C from the A4 will always play the base note (which you played on the keyboard) of the MS-20.


Hm, maybe im doing something wrong. I have the cv cable in the top left corner input like you described and the gate cable in the “normal” gate/trig in on the ms20. When playing the sequence from the A4 its only playing the same note, well not the same note but all the notes in the sequence have the same pitch. Smething i have missed here?


Did you remember to adjust the appropriate frequency modulation knob on the MS-20? Either EXT if you’re sending the CV to the FREQ input or T.EXT if you’re sending it to TOTAL.


Hey, this is cool. The frequency knob offcourse, how could i forget, hehe.
Somewhere between 8 or more towards 9 works for me. I will try some more tomorrow. Thanks once again.


Great to hear it works! There’s no transpose like keyboard transpose.


Praise be to this thread btw, took me a while but I got there. Now I’m triggering my MS20s farts from all the right places.


does anyone know how to correctly setup the A4 Hz/V CV-range to sequence the Ms-20 mini?


by trial and error i figured this settings
A2 = 0,869 V
A5 = 6,891 V

strange numbers but works ok


if the voltage nominally doubles per octave then it shouldn’t be ‘trial and error’ to get close, those numbers look close


Can i clock the MS=20’s Sample /hold with A4?
Doing any of this is still pretty foreign to me, and i"m still pretty fresh on the A4 still.
But I have 2 MS=20’s, and can probably be doing way cooler shit with them+A4 if i knew how to think about it.
Rn i have a really cool patch happening with the pair of Korgs all patched into one another, that if i could just sync the A4’s master clock to the clock of the “master” MS-20’s sample and hold, i could work this cool sound into a composition i have the rest of the stuff co-operating to perform.
Do i even make sense?


Couple of things to set straight first … the MS20 has its own way of doing things and that’s what makes it so very special imho (besides the glorious sounding voice) So conventional thinking if you’re used to more popular synth paradigms will get you stuck a bit; things like the Hz/v tuning, the modulation of the amp envelope and a few other things, including the ‘Sample and Hold’ - I’ve read it described as more of a ‘track and hold’ i.e. the input is always followed when open and the snapshot is taken when closed(held)
Now another idiosyncrasy of the MS20 is the ability to use grounding to trigger things (see screen print under the ‘passive’ button) - this means you can wire up an external push to close switch and ‘ground’ the action (as opposed to sending an active ‘high’ voltage to trigger things, this has advantages)
So to do this with the A4 you need to know that the Korg will pull to ground when you send a voltage that is lower than approx 1.3v - you can test this by setting a CV channel up as value lin, make the range be 0v to 1.5v and vary the value whilst connected to the S&H ‘clock’ (hook a slow ramp lfo to the input and put the output on the pitch) … you should see that when the voltage is high (i.e. value lin is at 127 that the ‘track and hold’ will pass the lfo through, but if you drop the value lin down to 100 or so, it’ll drop the voltage sufficiently to effectively ground the circuit (& then hold).
So you need to be able to drop a voltage beneath a 1.3ish threshold to act as a ‘clock’ in your case, now if you want a typical ‘S&H’ effect where the effect is steps, then all you need to do is set up e.g. an envelope which is targeting the value lin value (set it to zero on its main twiddle page (ie 0-127)) if you set all parameters of the Env to zero then you get a very fast voltage spike which momentarily exceeds 1.3v and allows the input through, but because it is so fast the ‘tracking’ isn’t heard, you just get the stepping effect whenever you play a key
So that’s how to get it going, to make it work best for yourself you’ll want to use any number of strategies to work the voltages - if you don’t want it linked to keyboard action you have lots of options to explore - remember that the MS20 noise section is quite low voltage, so as a mod source it’s underpowered, you’re best using the ramp LFO set fast to get a broader ‘random’ input to sample - the CV potential of the A4 is extremely powerful, so you ought to be able to get what you’re after with a bit of thought

Sequencing/Playing Ms20 mini from A4

I’ve read this like ten times, you are so generous.


Cheers, you’re welcome. Hooking other non MS things up to >gnd inputs was something I wanted to refresh in my head.
One thing to add, re noise level, is that there’s an easy to forget spare VCA on the MS20, so if you wanted a true random input source for the S&H circuit, just boost the noise through the VCA.
fwiw: It may also be simpler to use a clocked random(S&H) LFO directly from the A4 straight to the input you were feeding from the MS S&H circuit - use a CV track LFO on a Value Lin channel and set the appropriate Voltage range (refer to MS input labelling) and LFO modulation amount to taste - this way you still only use one A4 CV channel, but you have saved all the MS circuits for other duties :wink:


Just thought i’d add This Link to cross-reference a more recent thread as it contains some more setup info and other things to check for basic connection teething issues


This is great - I’ve been tweaking away all evening on the MS-20 under A4 control thanks to this - cheers!


I have a Ms20mini sequenced by a Analogkeys and it’s well sequenced except that the Ms20 never stop sounding. When I have one step, that note keeps on sounding all the time (till the next step ).

My configuration is:
Ms20 output to the inLeft of the Analog Keys
Pitch is controlled by the Cv A of the Analog Keys
Trig-in (of Ms20) connected to CVA/B of Analog Keys

source for the Cv A: CV track of Analog Keys
Source for the Cv B : Cv track of Analog Keys
CV B config: Gate/S-Trig/5.0V

Note length: 1/16

Could you help me?