Diva Vs. Real Analog

[aciddose]

it's clear the ADC (voltage meter) in your tester is a decent good one, likely much too expensive to attach to an entire bank of potentiometers.

there is no way this is true. buy a reasonable quality DAC with good DNL. if you use more bits than you need, the non-linearity is often lower than the number of bits you're interested in and you can use the extra bits to fine-tune values and store those in a table. ($5?)

connect the dac to a high-accuracy comparator ($2?) and locate the values between which the flag switches true/false.

for example your input is 5916, your bits are 16. start at 32768 - true. 16384 - true. 8192 - true. 4096 - false. 6144 - true. 5120 - false. 5632 - true. you should see where this is going. with 16 bits you have a maximum of 16 steps to reach any value.

that means you need to run this loop at 16x the desired sampling rate. if you're just measuring a knob you probably will be filtering that already and the rate you're interested in is not going to be more than 1khz. this is easy to accomplish!

if you're only interested in 12 bits, you can use the extra 4 bits to fine-tune linearity. you'll need a table with 4096 entries.

also keep in mind that you can add a bit by using a full-wave rectifier ( abs() ) with low-offset and high-linearity using an existing single polarity circuit. (also $2?)

the ADC on those chips is pretty well useless. that's designed to input basic parameters to the chip to test functions quickly while prototyping. it's also there to be hopefully "good enough" to do something simple like the volume knob on a remote control, or the controls for a gamepad/joystick or RC controller or so on.

it isn't designed to provide what you need. it's thrown in because it's cheap and general purpose.

if you're scanning controls on a precision instrument that is not general purpose.

you can add up to generally 32 (actually i can't remember where i get this impression. it's from experience.. might be to do with offsets or non-linearity or something. you might be able to get more!) channels easily using analog multiplexors. ($2 each, usually 1-to-4.)

[electro]

Much like the value encoder of the Little Phatty. Knobs On a positive note, we pretty much researched all technologies and suppliers for building a Diva controller. The microcontroller is working for most of what we want to do, so we might be seeing something soon. Can't wait to have a hands-on Diva in front of me

Cheers,

Urs

How do you build a controller for a synth with variable modules? It would be more sensible to do something like the Creamware ASB for specific emulations.
http://www.soundonsound.com/sos/may06/a ... amware.htm

[justin3am]

How do you build a controller for a synth with variable modules?

It's not so difficult. Particularly if there is a fixed number of modules and a known quantity of parameters. It probably also helps that he is developing the controller for a synth he also developed.

It would be more sensible to do something like the Creamware ASB for specific emulations.
http://www.soundonsound.com/sos/may06/a ... amware.htm

How is that more sensible?

[aciddose]

you don't need an unusually large knob

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it ain't the size of the thumb knob, it's the motion of the wiper.

[Urs]

I think the ideal solution are high res pots for each parameter and an encoder to fine control the last selected parameter. Much like the value encoder of the Little Phatty. Knobs for coarse settings, encoder for the small details.

Random thought (well, inspired by a calculator's mem assign and recall) - would it make sense to have a toggle-able locked assignment on the encoder? It might be nice to have that assignment stay static while tuning against other tweaks, or for a quick recall, or for a quick way to flip between two fine-tuning parameters.

This could be done with any form of firmware on the controller.

We're all kind of very excited about doing this, specifically also to check out what's good and what's not.

[phazedown]

delete-me

[JerGoertz]

you don't need an unusually large knob

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+1

[HcDoom]

Diva's filter are....something special, love it.

[bill45]

The proticol organ patch is probably the best organ patch I've heard in a VSTi,
But the cpu hit!I have an I7 920!I mean a four note chord will cause cubase5 cpu to hit 60%!

[Arksun]

Continuing the theme of knobs and sliders. Don't forget that for some cheap midi controllers with short sliders and such, the resolution you're getting probably isn't even 128 steps!.

On my old Roland synth the slider on that would do jumps of about 4 each time. So a filter sweep would be midi cc messages of 0, 4, 8, 16 etc, which of course sounded very stepped.

Simply smoothing it with the mouse in the DAW made it sound much.. well, smoother.

In many ways 128 steps is probably enough for a filter cutoff if its well interpolated by the synth itself, its more then a question of how well the synth interpolates between that points to make it sound smooth, but without affecting how quickly its able to jump between extreme values either.

[Urs]

One thing about analogue feel is that many knobs are very sensitive. Oscillator tuning knobs will often be so sensitive, they seem to move just by looking at them

I do believe that the .01 resolution in our stuff is just so sufficient to hit the right spot. However, using the mouse with shift all the time is tedious. Building a hardware controller with very good quality parts is thus also part of evaluating workflow options. Who knows what's possible

[Fred_Abstract]

and add some dsp to it ! that would open so much options with lot of dsp power.
to run diva at max quality with lot of voice and futurs uhe synths i would buy something like this in a heartbeat

[Urs]

and add some dsp to it ! that would open so much options with lot of dsp power.
to run diva at max quality with lot of voice and futurs uhe synths i would buy something like this in a heartbeat

We're looking into that. Unfortunately it isn't quite trivial to get that Total Integration thing going, or even DSP for what it matters. However, if the core of the built-in sound generation was a Linux system with an ethernet card, then one could probably use JACK or something to get the audio back into a DAW.

[william27]

Downloaded the demo and as far as a synth goes this thing is amazing. But you dang near have to go with using a second pc to get this thing to live up to its potential. Now watch me start a argument if you slap 61 keys on this thing a host of knobs to control things a lcd screen and bump the price up oh anywhere between $500 to $1500 every synth snob in here would be saying its the next best thing to a bloefield or the new sledge or access or the ultranova or the this or the that.
I have used every freakin plug under the sun along with some hardcore synths and this thing just made it on to my short list which includes
Trillian
Omnisphere
Nexus
Kontakt 5
And the access virus
Great job on urs part (now lets do something about that DSP)
How about a hardware device like the bloefield sledge or access or even like the ultranova
But keep the functionality of the plugin i rather like the interchangeable parts[/quote]

[trimph1]

you don't need an unusually large knob

.... ......... .......... .................... .................

it ain't the size of the thumb knob, it's the motion of the wiper.