Velocity Control of the P6 VCA's

The Sequential Prophet-6 Analogue Synthesizer

Moderator: Pym

Post Reply
Hector Space
Posts: 3
Joined: Wed Mar 09, 2016 7:03 pm

Velocity Control of the P6 VCA's

Post by Hector Space » Wed Mar 09, 2016 7:25 pm

To me, a pianist, velocity control is very important. It's why I didn't buy an P5 back in 82, so I'm very glad to see the P6 with both Velocity and Aftertouch. But the velocity control applied to the VCA's is extreme on the P6. Regardless of what setting I select the control signal drives the output to zero or pretty near at low velocities. In other words the dynamic range is too wide to be of any practical use. Currently velocity control isn't anywhere near what a piano would do, or indeed most synths. Especially when playing softly e.g. during a legato piece. It results in notes more or less disappearing and forces you to play more aggressively. Really one of the velocity settings should provide an offset or a more compressed scale for the VCA so as to limit quietness of the lowest volume. Please! :-\

drxcm
Posts: 11
Joined: Mon Jun 09, 2014 9:12 am

Re: Velocity Control of the P6 VCA's

Post by drxcm » Sat Mar 12, 2016 4:50 am

have you tried adjusting the keyboards velocity response in the settings?

Hector Space
Posts: 3
Joined: Wed Mar 09, 2016 7:03 pm

Re: Velocity Control of the P6 VCA's

Post by Hector Space » Sat Mar 12, 2016 1:51 pm

P6 velocity response is an issue. It currently does not work properly. None of the P6 velocity options improve the fundamental problem that low velocity values produce too little signal or volume. :o

I have conducted some velocity offset tests to determine what is required to fix the issue.
I used an Apple iOS App: Midi Bridge (Audeonic) running on an iPad to remodel the velocity values produced by the P6. This was done by turning P6 Midi local off. Midi Bridge receives the P6 Midi data stream, adjusts the velocity values received and transmits them back to the P6. For these tests I used the P6 default velocity scale of 0.

Please see the attached jpeg of the remodeled velocity curve needed to correct the problem. As you'll see the P6 input velocity of 1 needs to be offset by 33 in order to produce usable control. The curve isn't linear either (Although I tried it as a straight line from 33 to 127!) by experimentation I've found that to obtain the best control-ability in the middle ranges the response needs to be more exponential than it currently is. Note that this remodeled response also seems to work fine for the P6 filters. Please see the curve required in the attached jpeg image.

I hope DSI will be able to fix this in an update to the P6 firmware in the near future. :D
Attachments
P6RemodelledVelocityCurve.jpg
P6RemodelledVelocityCurve.jpg (770.44 KiB) Viewed 1016 times

Post Reply