Sequencing MS-20 mini with Analog Four

[Brandski]

Good evening,

I know that other topic deal with this subject but I have not found the answers I am looking for. I want to sequence my MS-20 mini with the A4.

• I want to send an envelope to the filter (instead of EG2)
• Assign an LFO from the A4 to the filter (instead of MG) [not both at a time, one or the other]

Here’s how it’s connected:

• CV A Hz / V for the pitch (in red on the diagram)
• CV B Gate S-Trig (3.0 V) (in green on the diagram)
• CV C Value Lin (-5V to 5V) for the LFO (in blue on the diagram)
• CV D Value Lin (-5V to 5V) for the ENV (in purple on the diagram)

I decided to connect the CV C (LFO) to the TOTAL jack to bypass the MG and not to affect the EG2
CV D (ENV) can therefore be used to replace EG2.

QUESTIONS :
-> Is it already good like that? : Lol:
-> If I wanted to send an envelope to the VCA, I branch where, INITAL GAIN, VCA IN, OUT or CONTROL INPUT ???

THEN:
I do not understand how the filter position on the MS-20 interacts with the VAL value sent by the LFO

-> To bypass the setting of the MS, should I open the HPF to maximum or zero?
-> What VAL I have to put in CV C / D so that the filter oscillates around this value, 64?
Because when I put 127, I still have the margin to open the filter on the synth …

-> can I assign any type of LFO from A4 or just SAW (-2.5 / 2.5V) and SQUARE (-5 / 5B) as original on the instrument?

Thank you so much !

[Devilfish]

All you need…

I watched the video 10 times or so. Really helpfull!

[Brandski]

Oh thank you!
Do you have an answer regarding this question : "If I wanted to send an envelope to the VCA, I branch where, INITAL GAIN, VCA IN, OUT or CONTROL INPUT ??? "

[pselodux]

CONTROL INPUT

This one!

edit: actually I don’t know how it works on the ms20… is that VCA separate to the one in the block diagram at the top? It doesn’t look like the input and output are normaled to anything… if that’s a separate one then you may have to patch signal into and out of it.

[avantronica]

^Indeed. That’s a separate additional VCA - to break the Env2 normal/routing just patch into Initial Gain for control of the VCA for the whole voice

The VCA next to S/H can amplify/scale a separate signal, its envelope is normalled to Env1 unless you feed Control Input with a modulation source

[pselodux]

Ah, interesting. I need to spend more time with the ms20. That additional VCA would be handy for pseudo-sequencing…

[Brandski]

Nice!
So, I can plug an ENV into the Initial Gain ? I tried and the output signal is much stronger !

Thank you for the advise about VCA 2
It gives 3 stages of amp with the ESP crazy !

[Brandski]

I’m having a great time since last week with my MS ! Thanks for your advices.

I noticed that the led next to the envelopes only lights up with MIDI control and not with CV / gate. does it change anything?

do some of you send a CV signal to the inital gain? The sound is much louder

[Brandski]

Hi there,
I switch from mini to the new FS model.
I have some questions regarding how to sequence the MS with an A4.

I try to send an Enveloppe to the MS.
As I understand from the MS patchbay, the ENV2 can’t be bypass. It is trig by the gate input and sum with the external one.
So, I decided not to connect a gate input. I use CV to VCOs and send an Enveloppe from A4 to LP Filter Cutoff and Initial Gain. Am I right so far?

Here my setup for Initial Gain, LP Filter and the Env applies to them.

Firstly, I am a little bit disappointing because the -5/+5v Initial gain input value requested is far from the internal VCA working. I have 0,72 to 3,24v sended by the A4. +5v is too loud!

Then, the Enveloppe curve received is very different from the internal one. The synth reaction is very different. Do you have any advice to get as close as possible? Which ENV type is better to choose on the A4 ? Thanks

[golddust]

The MS 20 expects 0 to 5 v (at least according to original manual, I believe it is also on front panel?) so if you are sending different values the envelope will most likely behave differently. I would set to 0 min, 5 max and see if they behave more as expected. I think you’ll have to deal with loudness issues through the master volume.

Also VCAs will not respond to negative voltage.

[Brandski]

Sorry, I made a typo.
I send 0,72 to 3,24v to the INITIAL GAIN and -5/+5 to the filter.

[golddust]

Yes, I understand, but you are sending 0,72 to 3,24v - not 0v to 5v as indicated on panel. The initial gain is tied to the VCA. The VCA expects 0 to 5 v. If you are not sending that then the VCA will be have differently. Initial gain knob should be at zero.

Let’s say your synth is a car that can go to 100 mph. The gas pedal is the “cv” you send to car.

With the max below 5v You are effectively putting something under your gas pedal - you can no longer push it to the floor - so you can longer push the car to it’s maximum acceleration.

By having your min value above 0 you are also effectively never taking your foot off the pedal, you are always moving (slowly) forward because you are always giving the car a bit of gas.

edit: Also ms 20 envelopes may be exponential - you may want to try exponential instead of linear - I don’t have an A4 but I assume that is an option (?)

[Brandski]

@golddust Thank you for your explanations and the analogy with the car

I notice that a 5v to the INITIAL GAIN produce a more louder sound than the internal ENV.
That’s why I limited my Enveloppe to 3.24v. But yes, you are right, it is better to send 5 volts and lower the volume.

And for the lower value, I set it to 0.72v because under that the VCA is not trig. So, I notice this free edge between 0 to this value where the Env sent do nothing. Do you agree?

[InTheAM]

I don’t have anything to add unfortunately but I did want to say once you get it working (I am horrid at this kind of stuff and I managed it when I still had those two boxes) the A4 sequencing the MS20 is a thing of beauty.