[sdiy] A different kind of polyphonic aftertouch

Richard Wentk richard at wentk.com
Fri Jan 5 11:57:30 CET 2018

Why would these methods be better than a switch? 

You’re only ever going to be measuring average travel time between two reference points. 

Do you think an SQ-80 had the processor power to do some kind of continuous numerical integration, and even if it did, would that generate a “more accurate” velocity measurement that somehow felt hugely more responsive to a player?

IME the biggest factor affecting playability is the quality of the mechanical action. 

E.g the DX7 had possibly the best semi-weighted action ever, with a good-enough mono AT mechanism. 

I don’t recall ever thinking it would have been improved with linear sensing. I do recall thinking “This is an exceptionally good action.” (Often followed by “I wish this had Poly AT...”)

The Ensoniqs had a clacky action that was distracting to play. Poly AT was very nice to have, but - unlike the DX7 - the keybed was always in the way. 

Nowadays most keybeds are crap. NI’s Kontrol series is bearable, Arturia’s keybeds have joke fake AT that ignores the sensor and simply fades in a simulated AT output with an envelope. Cheaper controllers (M-Audio, etc) are just horrible. The high end weighted Fatars are okay-I-guess, but a long way short of a good piano action.

The most interesting thing to appear for a long time is the Roli Seaboard, which has true poly velocity, poly pressure, and poly position sensing, and is also very playable (although it takes some getting used to.)

Bottom line is no one is bothered about linear sensing. They care how the keys feel under their fingers, and what they can do with them.


> On 4 Jan 2018, at 22:29, Mike HEQX <mike at heqx.com> wrote:
> As we see in the Ensoniq SQ-80 there is no physical switch. It was a change in inductance that was being measured and they did have a rubber pad under the key and they did give you polyphonic aftertouch ( not related I know ). So they used inductance, and someone else uses light, and yet another uses capacitance, and these are all linear sort-of systems that in my opinion are better than the two switch method of generating a psuedo-velocity sensitivity that measures time.
> So really the majority of synth keybeds that claim velocity sensitivity are really just sensing attack velocity. Some offer a choice of attack curve, which is artificially generated for you. Very few are actual hammer actions ( in the piano paradigm ), and very few are doing anything unique. Long live linear sensing!
>> On 1/4/2018 2:36 PM, cheater00 cheater00 wrote:
>> You put a spring or piece of rubber under the key and suddenly the
>> linear sensor is a pressure sensor.
>>> On Thu, Dec 14, 2017 at 6:46 PM, ASSI <Stromeko at nexgo.de> wrote:
>>>> On Thursday, December 14, 2017 5:09:40 PM CET MTG wrote:
>>>> https://deskthority.net/wiki/Adomax_Flaretech
>>>> "There are no electronics in the switch modules themselves. Instead,
>>>> surface-mounted infra-red optoelectronic components on the circuit board
>>>> provide the sensing in conjunction with a prism in the module's
>>>> transparent slider."
>>> So a vertical mouse, sort-of.  Which means it's very likely measuring key
>>> travel rather than pressure, which is a lot less useful for a musical
>>> keyboard.
>>> Regards,
>>> Achim.
>>> --
>>> +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+
>>> Samples for the Waldorf Blofeld:
>>> http://Synth.Stromeko.net/Downloads.html#BlofeldSamplesExtra
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at synth-diy.org
>>> http://synth-diy.org/mailman/listinfo/synth-diy
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy

More information about the Synth-diy mailing list