automation: the 89MotioN system

hey

I'm thinking about a new "automation" system around my 70' Studer desk, which is actually 12 patchable VCA, controlled from my DAW using DC signal.

The dream will be real motorized fader!
Did someone try or know someone who try to replace motor fader in a standard HUI DAW controller (mackie or similar) with audio taper motorized fader?  i mean using the same brand of fader (P&G, ALPS) if they share the same motor and servo track spec?

Zam

have a look at ucapps.de, there's a lot of activity there on this stuff.

Rochey said:

have a look at ucapps.de, there's a lot of activity there on this stuff.

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tks, i know this, but never look at the forum
after quick search it appear that ALPS are the most used in DAW controler
assuming it's the RSA series, there is no version with servo and audio track.
My "simple" idea seem not possible

only The P&G PGFM8000 seems to offer servo and audio tracks.

zamproject said:

assuming it's the RSA series, there is no version with servo and audio track.

Click to expand...

You want a 'Dual-unit' (servo+audio track), servo track is always lin.taper, audio track can either be lin, 10A or 15A taper.
For 100mm travel and concuctive plastic 10K log with 10A taper and without touch sense track, this might be 'RSA0N12M T0 D103'.

tks Harpo, but i don't find them on APLS website  :-X

I take more time on the ucapps forum and find interesting things

One guy made a controller close to a mackie clone with the MF_NG board (able to drive 8 motor fader)
He use P&G PGFM3200 series, and i have better look at the whole P&G product, the 8000 series seems to be a 3200 with a second track for audio or vca (depending on taper).
It should work 8)

i will catch a MF_NG board kit, it's cheap, I need to prototype this  :
the problem will be the P&G fader, 1 or 2 for test (my need is 32 :-\ )

Zam

Harpo said:

You want a 'Dual-unit' (servo+audio track), servo track is always lin.taper, audio track can either be lin, 10A or 15A taper.
For 100mm travel and concuctive plastic 10K log with 10A taper and without touch sense track, this might be 'RSA0N12M T0 D103'.

Click to expand...

i find this, should be good

http://www.ebay.de/itm/ALPS-Schieberegler-Motorfader-RSA0N12M9-touch-sensitive-10K-linear-log-Mischpult-/261440798809?pt=Bauteile&hash=item3cdf160059

did some one know where I can get ALPS K serie with audio and servo track, also P&G8000 series.
Of courses in very low qqtes (1 or 2 pces) just for prototyping...

I will start with the ALPS RSA, but audio spec are not so good regarding curve tolerance  , I have stereo modules, i need better matching.

zamproject said:

...but audio spec are not so good regarding curve tolerance  , I have stereo modules, i need better matching.

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So don't use a stereo pot to attenuate audio signals but use a linear mono pot instead to control VCA control port(s) that attenuate (or boost) audio signals. Maybe have a look at THAT design note DN116.

Harpo said:

zamproject said:

...but audio spec are not so good regarding curve tolerance  , I have stereo modules, i need better matching.

Click to expand...

So don't use a stereo pot to attenuate audio signals but use a linear mono pot instead to control VCA control port(s) that attenuate (or boost) audio signals. Maybe have a look at THAT design note DN116.

Click to expand...

Tks for link Harpo, so instructive, it could be an option (i also check THAT website an read some other "design note")

the good point of this is that i can use only one fader for my stereo chanels, easy for mechanical integration
I can also use "cheap" ALPS servo + VCA track

Bad point is it's not passive. As y say I already have a DIY patchable VCA automation trough insert, DAW controlled, but without moving fader of course.

another "bad point" is that fader physical position from "lin VCA" will not match virtual DAW/HUI audio fader position, but maybe I don't care as if I have moving fader, i will not use my Wacom to write volume automation anymore !

more investigation and prototyping on the way :

Zam

I'm working in a good way to do this with LDR, linearity is not a problem, already tested, but other concerns are in the middle, I think they shouldn't be a problem but I have no time to look a solution for them. I was controlling the leds from an arduino directly and a feedback with another LDR to the analog input of the arduino, it worked nice in a small range, I should add some analog circuit between the control and the leds to get a better curve than the direct (linear except for the led response) used so more bits are in fact usable, also an analog feedback instead of the digital used could be very simple and leave the analog inputs alone and just CV is needed. I was using discrete LDR/LED because I couldn't find any optocoupler ready, but it may be better or at least easier. Just tried two pairs of LED/LDR both from the same bag and matched really nice, the third one I tried looked like a bad LDR so no problems there and those where all the LDR I had at that time.

JS

little update

"moving fader" motor driver pcb from MIDIbox is on the way. It work under HUI protocol
I already made some test with ALPS fader with both audio and servo track, basic mechanical integration in my fader module...

also a 3D rendering for the final goal

I can load TKD fader
I keep the big EAO swithes for my PFL... like them  :
Add 7 ITT button for DAW remote:
"Solo" and "mute", "read" and "write" for automation
one "select", and 2 "F" (function key) that I can assign for what I want
also LED for each one

i'm thinking to double the mute command with a relay paralleling my existing switches in the Studer (FET mute)

voilà !

Zam

Work in progress !!!

https://dl.dropboxusercontent.com/u/95767560/IMG_0265.mov

Have noise issue to fix, some HF clock leak to my audio signal
Also some pitch bend conversions table to match DAW log scale and analogue fader log scale.

Zam

the switches control mutes and solos in the daw channel or in the analog mixer channel?

the second would be very useful!

also, you know if it is possible with that midiboard project to make the motorized fader switch between controlling audio fader and daw fader? sort of like the ssl consoles

really interested in this project! please keep posting your updates!

beatnik said:

the switches control mutes and solos in the daw channel or in the analog mixer channel?

the second would be very useful!

also, you know if it is possible with that midiboard project to make the motorized fader switch between controlling audio fader and daw fader? sort of like the ssl consoles

really interested in this project! please keep posting your updates!

Click to expand...

the goal is that mute and solo button control the DAW, BUT mute from DAW will also control a relay in parallel of my actual analogue (FET) mute switch, easy retrofit.
I have no need for solo function at mixdown, and as I have no solo bus on the desk (only PFL) it's complicate to add this function, i keep solo only at DAW side.

The fader actually control the DAW fader, both way, like any MCU/HUI devices, but as it is a real passive fader(with servo track) you can not disconnect one function from other (DAW volume and analogue volume)
Maybe SSL use VCA fader with CV standby when you are in DAW mode only?

At the end the DAW fader will be only to print automation for the analog side, multi track output to the Studer line input will be done from DAW prefader aux send.

Zam

Watching with interest..

ruairioflaherty said:

Watching with interest..

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tks ! i will update time to time

I try to solve noise problem due to PWM driver, and touch sensor 1kH trig...
Did someone know what driver type/technologies is used with hi end moving fader?

I try to smooth the PWM with big caps, work in a way, but target always mis-shoot.
what about a RC lpf, can I ad some resistive load to a L293 output ? i find nothing about this in the datasheet.

This week i will start modification to the software side, and i'm not good at this

Not to derail your thread but an idea I had was to tap the voltage on a standard moving fader (non audio as used in something like the Mackie Control or Avid Artist) and scale the voltage and filter before using it to control a VCA. 

that's my backup idea, putting (moving) fader to my actual VCA automation
But for a nice discrete console, I hope I can find a noise free, accurate and passive system

you might want to have a look at the studer documentation on the 970 / 980 / 990 series desks over at the studer ftp site. the fader module has may be a few clues on how to do this...

very impressive what you have achieved so far.

- michael

audiomixer said:

you might want to have a look at the studer documentation on the 970 / 980 / 990 series desks over at the studer ftp site. the fader module has may be a few clues on how to do this...

very impressive what you have achieved so far.

- michael

Click to expand...

tks michael

I already look at the 980, for the motor fader version and schematic there is nothing more than a arrow at the fader component pointing a text with "UPTOWN"  :-X