Discussion about the Korg PolySix synthesizer group photo

Yahoo Groups archive

Discussion about the Korg PolySix synthesizer

Archive for polysix.

Index last updated: 2026-03-30 01:17 UTC

Thread

Velocity Sensitivity

Velocity Sensitivity

2015-10-20 by chipaudette@yahoo.com

Hi All,


As you might now, I've had a long road of fun modifications to my Polysix.  I've replaced the keybed with a sweet Fatar.  The new keybed enabled me to implement aftertouch pitch vibrato, which is cool.  Putting in the pitch vibrato also enabled me to do portamento and variable-detuning for my Unison mode.  Those are very cool additions.


The new keybed also gave me dreams of adding velocity sensitivity to the Polysix.  It's been a long time, but I'm finally diving into it.  I'm making my Polysix have velocity senstivity!


If you're interested, here's a high-level overview of my plan:


http://synthhacker.blogspot.com/2015/10/velocity-sensitive-polysix-dream.html


More details are coming in follow-up posts.


Has anyone else added velocity sensitivity to any of their synths (Polysix or otherwise)?  How did you do it?


Chip


Re: [PolySix] Velocity Sensitivity

2015-10-23 by Florian Anwander

Hello,

There are two topics to think about:
1.) Do you want to add the velocity also to the VCA control (means: gate
and env to the VCA are sensitive).

2.) The envelope amount of the original Polysix is not simply an adder,
but the sustain voltage is used as an negative offset to the Cutoff
frequency. It is not a 100% offset like at yamahas polyphonic CS-series,
but it is about 40%. You can test it out if you set the attack,, decay
and release to minimum and set sustain to ~10:30 position. The turn up
the envelope amount and you will find that the cutoff frequency does not
change (or nearly does not change).

Florian

Re: [PolySix] Velocity Sensitivity

2015-10-23 by chipaudette@yahoo.com

Hi Florian,

On your first point, regarding also affecting the VCA, the Polysix schematic makes it look harder to affect the VCA envelope as the VCA CV comes direct off the Envelope IC (via a solid state switch).  In other words, the envelope for the VCA never leaves the per-voice section of the circuit.  This is in contrast to how the envelope is sent way away from the per-voice section of the circuit, it is multiplexed, and is then modified by the "EG Int" processing.  If I target just the VCF envelope, I only need one circuit (not six) and it's a simpler modification.  Maybe in the future, once I gain confidence, I can also make the VCA envelope be velocity sensitive.

On your second point, regarding how the "EG Int" also adds an offset to the VCF cutoff, I'm all over that.  I detected it pretty quickly after getting the Polysix and I thought that it was a nice touch.  My plan is to affect attenuate the envelope itself and NOT modify how the EG Int is applied.  As a result, the way that the EG Int applies the offset will be unaffected by the velocity.  I think that this will result in the most natural sound.

Chip

Re: Velocity Sensitivity

2015-10-23 by chipaudette@yahoo.com

Step #2, I've figured out the Polysix's approach to multiplexing the VCF envelopes.  My approach to modulating the envelope based on note velocity is taking shape...

http://synthhacker.blogspot.com/2015/10/velocity-sensitivity-understanding.html

Chip

RE: [PolySix] Re: Velocity Sensitivity

2015-10-25 by target.nine

Chip - that's darn cool. Great work, and patience!
From: chipaudette@yahoo.com [PolySix]
Sent: ‎25/‎10/‎2015 13:06
To: PolySix@yahoogroups.com
Subject: [PolySix] Re: Velocity Sensitivity

 

Step #3 is complete...I've figured out the addressing and synchronization of the multiplexing process.  Now I now how my "Velocity Processor" can stay synchronized with the multiplexing of the VCF envelope.



Chip



Re: [PolySix] Re: Velocity Sensitivity

2015-11-08 by Ben Stuyts

Nice work!

Ben

> On 08 Nov 2015, at 16:36, chipaudette@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:
>
>
>
> My velocity sensitivity works! You can check out demos here:
>
> http://synthhacker.blogspot.com/2015/11/korg-polysix-with-velocity-sensitivity.html
>
> There are two demos in there right now...at the top is a piano/clav demo and at the bottom is an organ vamp.
>
> The added expressiveness of the velocity sensitivity is fun!
>
> Chip
>
>
>
>

Re: Velocity Sensitivity

2015-11-08 by reboot@hotmail.com

you bring the polysix more far than "normal" midi kits ...

keep on !