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General Discussions => Truth Table => Topic started by: Juanpcdiy on March 06, 2019, 05:25:04 PM

Title: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 06, 2019, 05:25:04 PM
the idea is to make an Open Source Hardware & Software,
to control Analog Audio Hardware with Digital signals, like a dummy plugin that has Total Recall in VST, AAX & AU.

WesAudio already has a similar project, but is Not designed to retrofit older vintage equipment, its designed for New HW.
by USB
but the principle is similar / same..

to modify existing hardware and clones from any manufacturer...
and be able to control it
like mixanalog.com
by Ethernet
but open source.

Digitally controlled Analog.

Relays, VCA, AD, & DA are basically the building blocks for the HW,
the hard part is the Software, because it also needs to download the Steiberg & Avid developer SDK.

maybe a Stand alone version would be enough, for version 1.0
Requirements:
Must Be OSX, Windows & Linux/FreeBSD compatible... "Multi Platform",x86_64 & RISC.  "future proof."
Must be OSX Maverics compatible 10.9.5 minimum.. "backward compatible" compiled with older version of Xcode.
preferably OSX 10.6.8 SnowLeopard compatible...
must be as compatible as possible.
must be as low latency as possible, RealTime if possible.
must have common parts, time proven, time tested, Not obscure or very obsolete.

i think this is the future...
McDSP the plugin company is also making a Digitally Controlled Analog HW.
Waldorf had a 16 channel DCA Low Pass Filter Box,
Summit Audio also has a DCA EQ.

like the movie, Back to the Future, where there is a billboard in the future, to convert any vehicle to a flying car... for $49.999

Not MIDI because it has 7-Bits, and thats too little for some things, maybe having an offset to fine tune could work too...
if CC has 156 steps per Hz.
a EQ that can swept from 0Hz to 20050Hz,
at CC 64 would be 10025Hz
at CC 32 would be 5012.5Hz
at CC 63 =9868 Hz
at CC 65 = 10181Hz
at CC 33 = 4855Hz
at CC 31 = 5169Hz
 
i feel MIDI is too coarse.
Yamaha DSP Factory volume control had a mathematical formula to change the volume smooth between MIDI jumps...
like Lag circuit.

 
Title: Re: Open Source Digitally controlled Analog Project...
Post by: gyraf on March 07, 2019, 02:11:23 AM
Good idea - would be great to have an open standard supporting this.

Maybe base it on some common hardware like a simple serial port under USB? That way you can circumvent some of the driver problems.

Would be great to interface to likeminded people like https://mixanalog.com/ and https://accessanalog.com/

Jakob E.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: zamproject on March 07, 2019, 07:20:33 AM
Hello

Midi is a good protocol and can be used with NRPN for extended 14bit data
USB or ethernet (RTP-midi)
About no driver issue...

Have a look at http://ucapps.de/ (http://ucapps.de/) for the HW and embedded SW.
almost everything is possible, I use this platform for my fader automation, work great.

Best
Zam

Title: Re: Open Source Digitally controlled Analog Project...
Post by: mhelin on March 07, 2019, 07:24:57 AM
Not MIDI because it has 7-Bits, and thats too little for some things, maybe having an offset to fine tune could work too...
...
i feel MIDI is too coarse.
Yamaha DSP Factory volume control had a mathematical formula to change the volume smooth between MIDI jumps...
like Lag circuit.

MIDI 1.0 is 7-bit.

Maybe it's time to move to MIDI 2.0.

Or maybe not in this case as OSC could be a better protocol than MIDI 1.0/2.0.

It's also used on Behringer X32, so you could just borrow X32 control messages.

https://behringerwiki.musictribe.com/index.php?title=OSC_Remote_Protocol

Better documentation here:
https://www.academia.edu/9709659/UNOFFICIAL_X32_OSC_REMOTE_PROTOCOL

Effect parameters starting from page 85.

More reading:
Introduction:
http://opensoundcontrol.org/introduction-osc

File area, various projects:
http://opensoundcontrol.org/files


Title: Re: Open Source Digitally controlled Analog Project...
Post by: zamproject on March 07, 2019, 07:53:48 AM
MIDI 1.0 is 7-bit.

No...

RPN/NRPN do 14bit...
sysex can even do more...

Best
Zam
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 07, 2019, 08:51:49 AM
Not MIDI because it has 7-Bits, and thats too little for some things, maybe having an offset to fine tune could work too...
if CC has 156 steps per Hz.
a EQ that can swept from 0Hz to 20050Hz,
at CC 64 would be 10025Hz
at CC 32 would be 5012.5Hz
at CC 63 =9868 Hz
at CC 65 = 10181Hz
at CC 33 = 4855Hz
at CC 31 = 5169Hz
 
i feel MIDI is too coarse.
Do you want 1 Hz resolution all the way?
Think different; you have 127 steps over a range of 10 octaves; each step would be 1/12th of an octave, which is not bad. At 5k, the next step would be 5.3k.
It would not be enough for surgical EQ, but for tone control, I could work with it.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: zamproject on March 07, 2019, 09:46:19 AM
Do you want 1 Hz resolution all the way?
Think different; you have 127 steps over a range of 10 octaves; each step would be 1/12th of an octave, which is not bad. At 5k, the next step would be 5.3k.
It would not be enough for surgical EQ, but for tone control, I could work with it.

I totally agree...
then again, if you want more use RPN/NRPN up to 16384 steps...

But after that be ready to design a HW that properly convert a more than 7bit data to analogue function.
Good DAC design practice, digital pot (over 1024 steps 10bits ?) etc...

Best
Zam
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 07, 2019, 10:44:20 AM
I totally agree...
then again, if you want more use RPN/NRPN up to 16384 steps...

But after that be ready to design a HW that properly convert a more than 7bit data to analogue function.
Good DAC design practice, digital pot (over 1024 steps 10bits ?) etc...

Best
Zam
When digitally-controlled analog mixers were considered a viable option, several techniques were considered, including digipots and photoresistive optocouplers; only two remained: DC-driven VCA's and MDAC's. Although more expensive, the VCA solution was preferred by several designers because of the absence of the dreaded zipper noise. The lack of resolution of digipots was an unanimous no-go.
Of course, the appearance of decent digital mixer put a stop to hybrid mixers.
For the subject at hand, I would say that digipots are an adequate answer since they don't require modification of the analog circuitry. There are some possibilities regarding the issue of resolution:
Now if the idea is to build a dedicated HW, without any reference to an existing one, I would follow the path of those who've treaded it successfully before and go for MDAC's.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: JohnRoberts on March 07, 2019, 11:07:57 AM
When digitally-controlled analog mixers were considered a viable option, several techniques were considered, including digipots and photoresistive optocouplers; only two remained: DC-driven VCA's and MDAC's. Although more expensive, the VCA solution was preferred by several designers because of the absence of the dreaded zipper noise. The lack of resolution of digipots was an unanimous no-go.
Of course, the appearance of decent digital mixer put a stop to hybrid mixers.
For the subject at hand, I would say that digipots are an adequate answer since they don't require modification of the analog circuitry. There are some possibilities regarding the issue of resolution:
  • Either accept the limited resolution and live with it; after all, I don't know any HW EQ that has a range of 20Hz to 20kHz in a single range
  • Use range switching; if the HW is not ready for that, it can be implemented as an add-on
  • Cascade digipots; an 8-bit 100k in series with a 5k provide a 5000 points resolution (12-bit)
Now if the idea is to build a dedicated HW, without any reference to an existing one, I would follow the path of those who've treaded it successfully before and go for MDAC's.
Digitally controlled analog mixers have been around for decades but failed in the market as prohibitively expensive. The huge cost/benefit and massive feature set increase offered by modern digital mixer platforms put the final nail in digitally controlled analog coffin.

BTW zipper noise can be managed by coordinating digital pot gain changes with signal zero crossings. The gain change times zero, equals zero.

I would vote for DPOTs to retrofit into existing designs, but this will not be trivial, and market may not support NRE.

JR
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 07, 2019, 11:49:33 AM
BTW zipper noise can be managed by coordinating digital pot gain changes with signal zero crossings. The gain change times zero, equals zero.
That's correct; but pioneer designers had so many things to struggle with in terms of software, adding the necessary hardware and code lines was overwhelming for many of them. In addition it turned out that performance was better with MDAC's.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 07, 2019, 12:06:57 PM
#1. i have an UPS from Forza FX-1500 & Fx-2200,
has Serial USB port,
but software is a nightmare...
needs Java+Flash,  sometimes eats 100% CPU of a G4400 doing nothing... or 1-core of a i7-970,
the port is locked to 1 USB port, if you move the USB cable to other port, software wont work unless you force it "hack it".

a friend also has an older UPS from same manufacturer, and the latest software is Not compatible...
i had Not good experiences with Serial-USB interfaces.
maybe is just bad luck.

i have my doubts about serial-USB, i think Ethernet is better...
Waves Soundgrid has Ethernet..
DANTE also has Ethernet,
Solid State Logic, Ethernet...
rptMIDI works great,
AVID / Euphonix control surfaces, Ethernet.

i had better experiences with Ethernet, than serial-usb, im biased towards Ethernet.

#2. MIDI 14-Bit is a nice idea, but is Not compatible, Not supported,
for example:
Peavey Cakewalk Studio Mix controller, it was revolutionary, 14-Bit MIDI controller...
what happened?
Died... Abandonware, Obsolete.
software developers never supported 14-Bit MIDI controllers...
someone did a custom firmware chip and a software,  to make it more compatible,
but also disappeared...
forgotten.
most Peavey Studio Mix owners never purchased the upgrade.
Abandonware,
and still is an amazing hardware, advanced for its time, but if software developers dont support it, its useless.
 
#3. MIDI has low bit rate, 32kbps, too low, its like Ethernet v0.5, has similar twisted pair technology.
DMX its a bit better, "MIDI 3.0", instead of 5-pin din, its 3-pin XLR, sometimes 5-pin XLR, more robust for live rental.
but still, Not convinced... i use it for disco dj mirror lamps but... does Not feel as powerful as Ethernet. XLR is better than RJ45, plastic tab breaks too easy, but repair is easy with a punch machine, and high quality connectors with longer blades..

but also Not as popular,
All computers have Ethernet,
None has DMX,.

#4. MIDI is very unstable, "stuck Notes", i use the MIDITest software v4.12 32-Bit to analyze many different OS & MIDI interfaces, OSX & Linux with Wine / PlayOnMac.
 
the best MIDI Interface was the True MPU-401 included in older Pentium4 boards, and some Athlon XP Joystick ports...
lowest jitter, lowest deviation, lowest latency.
+ WindowsXP,
also some SoundBlaster cards have a Nice MIDI... "Not all"
most USB Midi is crap, the ones ive tested.
except Focusrite 18i20 MK2,

i still have a P4 478, with rtpMIDI as a midi interface...
like a cheap  noisier RedBox rptMIDI interface.

#5. Digital Controlled Analog failed the market because Digital technology was born, was difficult, was expensive,
but those variables are gone now...
Digital technology is cheap & easy available Now.

#6. DPOTs are 8-Bits, "Better than MIDI, as good as DMX but still Not as good as VCA + 10 or 12-Bit DA."
smaller & cheaper, than VCA, Yes.

#7. Mastering analog equipment has steps, to recall settings, Not because having 12 steps is cool.
Digital Controlled Analog can have Total Recall Analog, with 10-bit or 12-Bit precision.
1024 to 4096 steps.

to have analog feel must be like MIDI Pitch Bend Wheel.
16,384 possible values. General MIDI specification recommends that the total range be ±2 semitones,
though this Pitch Wheel Range (or Sensitivity) can be adjusted using General Midi Registered Parameter Number 0, 0.

https://en.wikipedia.org/wiki/Pitch_wheel

10-Bit = 1024
11-Bit = 2048
12-Bit = 4096
13-Bit = 8192
14-Bit = 16384
15-Bit = 32768
16-Bit = 65536
24-Bit AD is for very advanced/expensive Bench Multimeters...7.5 6.5 Keithley, Agilent, Rigol, Fluke, Siglent, HP, etc...

for all controls to have 14-Bit resolution, 32kbps is Not enough, barely works for MIDI.
the idea is Not to re invent the wheel, to make MIDI v4, is to use what is already available.

i had the Novation SL 61 mk1 Keyboard with AutoMap, and the 128 steps without lag, was very annoying... Yamaha DSP Factory + Nuendo 3 / Cubase implementation was much better, moving the Mouse Wheel feels way better, less noticeable.
Also AutoMap cannot be implemented with Protools 12 security methods.

the same EQ plugin with Mouse had a lot better resolution, with CC was very disappointing when i want to dial a specific frequency between CC 70 -&- CC 71, very disappointing. 

#8. Focusrite 18i20 Mk2 has Digitally Controlled volume, very interesting design...
Title: Re: Open Source Digitally controlled Analog Project...
Post by: JohnRoberts on March 07, 2019, 12:50:38 PM

#2. MIDI 14-Bit is a nice idea, but is Not compatible, Not supported,
for example:
Peavey Cakewalk Studio Mix controller, it was revolutionary, 14-Bit MIDI controller...
what happened?
Died... Abandonware, Obsolete.
software developers never supported 14-Bit MIDI controllers...
someone did a custom firmware chip and a software,  to make it more compatible,
but also disappeared...
forgotten.
most Peavey Studio Mix owners never purchased the upgrade.
Abandonware,
and still is an amazing hardware, advanced for its time, but if software developers dont support it, its useless.
 

I can not speak about the software support (Cakewalk) but I know a little about the hardware effort (the Studio mix product manager reported to me inside Peavey). 

Yes this was a pretty slick piece but the market did not embrace it.. I don't know if there was a chicken/egg thing with poor market acceptance leading to insufficient software support, or insufficient software support causing the weak market performance. Either way I ended up with a pile of unique hardware I had trouble moving even when discounted below my cost.

That is often the case with novel products, great enthusiasm and optimistic market projections before the market reality, that did not deliver the numbers.

JR
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 07, 2019, 06:34:25 PM
Returning to the topic...
2nd Chapter:
Hardware Approach.

Invasive vs. Non Invasive...

2 different approaches,,,
mixanalog is Invasive,
https://youtu.be/ymK71LwNxWw?t=40
https://www.instagram.com/p/BfiSGRAhV_b/

accessanalog is Non-Invasive.
https://www.instagram.com/p/BtMcEY1h6Oi/

Pros & Cons:
Non-Invasive actuator pressure must be as low as possible to avoid increasing wear damage.
Invasive can affect sound, in some equipment, there is a risk of inducing EMI, RFI into the equipment if Not done properly.

Non-Invasive is easy to implement, servos are available from all sizes, but is louder/noisier, also increase power consumption.
Invasive can last longer, has almost No moving parts apart from Relays that can be replaced by IGBT or MOSFETS or JFETs, or BJT = Silent, can have No moving parts, but where absolute signal integrity is required Relays may be the best option..

TQ2-5V is a proven part...
(https://www.helios-online.nl/fotos/7260_foto4_product_org.jpg)

thoughts?

invasive seems a lot more work...
dont know why i like more the invasive approach.
probably has more accuracy and repeat ability.

for example:
My RSP Saturator Drive control has 10KB, i have installed A & C types, or has C and i have installed A & B types, cant remember,
anyway... one type is very aggressive, the other is too soft, the original had a nice balance... but its imposible to find, very rare..
i think original was type C, and Now i have B in once side and A in the other... to have 0 Drive i must have completely different settings. Drive goes from -3dB to Way too loud. LOL Jajajajajaja
https://groupdiy.com/index.php?topic=37133.0 (https://groupdiy.com/index.php?topic=37133.0)

if using the invasive approach equipment can be improved to have different curves in potentiometers...
maybe someone likes more A, or B or C type Potentiometers...
Equipment can be improved with invasive technology.
also some brands of pots sound better than others, even having same resistance... dont know why...
fake alpha does Not sound as good as generic unbranded type, for example.

http://www.alphapotentiometers.net/html/taper_curves.html
http://www.alphapotentiometers.net/html/24mm_pot_2.html

on the other hand, a Knob or connector from the pot to the servo can be done very easy with 3D printers,
STL files, nylon or PLA, or ABS...
external approach is easier but Not as powerful.

https://www.servocity.com/servos (https://www.servocity.com/servos)

Title: Re: Open Source Digitally controlled Analog Project...
Post by: iampoor1 on March 08, 2019, 12:49:52 AM
The problem with a project like this is defining its scopes and limitations.  ;D

The relay control approach is right for some applications, the VCA approach is right for some applications, and the Digital pot is perfect for some applications (AD5290 is the best I know of).

It might make sense to implement all of these as possible options, within a framework, and then develop it bit by bit (no pun intended)

Also, my vote is for NRNP midi.... 14 bits is enough resolution. There are enough challenges with implementing something like this in the first place, no need to reinvent the wheel......
Title: Re: Open Source Digitally controlled Analog Project...
Post by: gyraf on March 08, 2019, 02:52:34 AM

Non-Invasive is easy to implement


It most certainly ain't.

I've been working on this on and off for 6-7 years, and haven't found a solution that works even halfway well half the time. And I was not the only one researching in that direction.

Chris Barett of accessanalog.com is a bona-fide mechanical genious, that's how he managed to pull the stunt with that working system. I had a chance of a very-close look at NAMM, and what he does is not trivial, nor to be underestimated, even though the superficial impression is simple enough.

Jakob E.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: iampoor1 on March 08, 2019, 04:01:51 AM
It most certainly ain't.

I've been working on this on and off for 6-7 years, and haven't found a solution that works even halfway well half the time. And I was not the only one researching in that direction.

Chris Barett of accessanalog.com is a bona-fide mechanical genious, that's how he managed to pull the stunt with that working system. I had a chance of a very-close look at NAMM, and what he does is not trivial, nor to be underestimated, even though the superficial impression is simple enough.

Jakob E.

+1

I think the OP thinks this is FAR easier than it really is.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 08, 2019, 04:08:36 AM
My RSP Saturator Drive control has 10KB, i have installed A & C types, or has C and i have installed A & B types, cant remember,
anyway... one type is very aggressive, the other is too soft, the original had a nice balance... but its imposible to find, very rare..
i think original was type C, and Now i have B in once side and A in the other... to have 0 Drive i must have completely different settings. Drive goes from -3dB to Way too loud. LOL Jajajajajaja
https://groupdiy.com/index.php?topic=37133.0 (https://groupdiy.com/index.php?topic=37133.0)

if using the invasive approach equipment can be improved to have different curves in potentiometers...
maybe someone likes more A, or B or C type Potentiometers...
Equipment can be improved with invasive technology.
also some brands of pots sound better than others, even having same resistance... dont know why...
fake alpha does Not sound as good as generic unbranded type, for example.
That is a new one for me, the sound of potentiometers! I knew all the crap about the sound of rectifiers, power cables, but now, that's a new high.
I'm eager to hear about the sound of switches.
Replacing a RevLog type with a Lin type only changes the way the effect changes with percentage of rotation. Indeed, for identical positions of the pot, the effect will be different, except at the ends. I would be very surprized if it's not what you hear.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: mhelin on March 08, 2019, 09:11:15 AM
I can not speak about the software support (Cakewalk) but I know a little about the hardware effort (the Studio mix product manager reported to me inside Peavey). 

Yes this was a pretty slick piece but the market did not embrace it.. I don't know if there was a chicken/egg thing with poor market acceptance leading to insufficient software support, or insufficient software support causing the weak market performance. Either way I ended up with a pile of unique hardware I had trouble moving even when discounted below my cost.

That is often the case with novel products, great enthusiasm and optimistic market projections before the market reality, that did not deliver the numbers.

JR

I still have StudioMix though it doesn't have much use.  It had a software bug which was never fixed, it caused random values to LSB of the 14-bit NRPN's used in automation so when there was some workaround in Cakewalk the resolution was not fully used. Some engineer in Germany though found and fixed the bug and was selling a new ROM with some enhanced features, never bought it cause I happened to locate the problem area in ROM code as well and fixed 8051 assembler code bug there. I also created another ROM image. It is still in the file area of StudioMix Yahoo group, I guess. The buttons on the device are heavy and springy, not very good to use. It also had a mic pre (mic in line out).

E: Yes, the file is still there:
https://groups.yahoo.com/neo/groups/studiomixmap_group/files
smix.zip

The enhanced fadeOS can be get from Sonicware:
http://www.sonicware.de/studiomix/studiomix_en.html
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 08, 2019, 10:07:51 AM
#1. if i think its easy, i would Not ask open for public help...
 i would do it my self.

#2. there are mercury filled relays in vacuum atmosphere because relays affect rise & decay time... mechanic has latency, Silver, Copper, Gold, Carbon, have different Electric Resistance.
temperature affects resistance,
if you cannot hear that, Not my problem...

can be measured with a powerful eqipment,
if you thinkan oscilloscope is better than your ears that have millions of years in evolution, think again. LOL Jajajaja.

has been proven that some chemicals reduce hearing ability,
https://en.wikipedia.org/wiki/Hearing_loss#Causes
https://en.wikipedia.org/wiki/Sensorineural_hearing_loss#Causes
https://en.wikipedia.org/wiki/Quinine#Beverages
https://en.wikipedia.org/wiki/Cinchonism
https://en.wikipedia.org/wiki/Ear_protection

"if i can´t nobody can, mentality..."
i think more: "if someone can, i can." LOL Jajajajajaja

Carbon has different states/types, Carbon is Not just 1...
and they all have different properties.
Diamond
Graphite
Graphene
Graphenylene
AA'-graphite
Amorphous
Fullerene
Carbide-derived carbon
Linear acetylenic carbon (LAC)
D Q T M-Carbon
Activated Carbon
Carbon fibers
etc...
https://en.wikipedia.org/wiki/Carbon_fibers
https://en.wikipedia.org/wiki/Activated_carbon
https://en.wikipedia.org/wiki/Allotropes_of_carbon
https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Resistivity_and_conductivity_of_various_materials
https://en.wikipedia.org/wiki/Electrical_resistance_and_conductance#Relation_to_resistivity_and_conductivity
https://en.wikipedia.org/wiki/Admittance
https://en.wikipedia.org/wiki/Electrical_impedance
https://en.wikipedia.org/wiki/Electrical_reactance
https://en.wikipedia.org/wiki/Susceptance
https://en.wikipedia.org/wiki/Valence_and_conduction_bands
https://en.wikipedia.org/wiki/Skin_effect
https://en.wikipedia.org/wiki/Conductivity_(electrolytic)

#3. i like to write, helps to organize ideas... to see things i miss.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 08, 2019, 10:28:58 AM
if you thinkan oscilloscope is better than your ears that have millions of years in evolution, think again.
Typical audiophool speech...

Quote
Carbon has different states/types, Carbon is Not just 1...
and they all have different properties.
Do you think I don't know that? Potentiometers use carbon and various other substances, but their use is always to provide a variable resistance. Other properties are essentially irrelevant. Same with speaker cables; whether they are made of copper, aluminium, silver or gold, as long as they have the same resistance, their transmission properties at audio frequencies are identical.

Quote
https://en.wikipedia.org/wiki/Allotropes_of_carbon
https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Resistivity_and_conductivity_of_various_materials
https://en.wikipedia.org/wiki/Electrical_resistance_and_conductance#Relation_to_resistivity_and_conductivity
https://en.wikipedia.org/wiki/Admittance
https://en.wikipedia.org/wiki/Electrical_impedance
https://en.wikipedia.org/wiki/Electrical_reactance
https://en.wikipedia.org/wiki/Susceptance
https://en.wikipedia.org/wiki/Valence_and_conduction_bands

https://en.wikipedia.org/wiki/Conductivity_(electrolytic)
You may accumulate loads and loads of internet sources, they all say the same, and may not be particularly relevant.

Quote
#3. i like to write, helps to organize ideas... to see things i miss. 
It's fine as long as you don't take too much bandwidth. At the moment you are essentialyy talking to yourself.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 08, 2019, 11:01:28 AM
The problem with a project like this is defining its scopes and limitations.  ;D

The relay control approach is right for some applications, the VCA approach is right for some applications, and the Digital pot is perfect for some applications (AD5290 is the best I know of).

It might make sense to implement all of these as possible options, within a framework, and then develop it bit by bit (no pun intended)

Also, my vote is for NRNP midi.... 14 bits is enough resolution. There are enough challenges with implementing something like this in the first place, no need to reinvent the wheel......

DPOT is 8-Bits, 14-Bits is Overkill

the logic thing to do, is to use 2x CCs for 1x DPOT,
CC#        0-127 for 0~50%
CC#+1   0-127 for 51%~100%.
but that can create opposing forces.
works like a Non-RAID BIG/SPAN architecture.
https://en.wikipedia.org/wiki/Non-RAID_drive_architectures

or maybe:
CC# Pair
CC#+1 Impair,
alternating values like RAID 0. "Stripped"
but automation would be too much complicated, drawing a simple curve would be almost impossible, without a pair/impair splitter.
https://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_0
https://en.wikipedia.org/wiki/Nested_RAID_levels

there are only 127 CC per Channel = 64 DPOTs or Relays per MIDI Channel, 16-Channels per MIDI Port...
but...
DMX machines use Channels for features, and CC ranges for On-Off features.
DMX Values table:
https://www.chauvetprofessional.com/wp-content/uploads/2015/07/Q-Spot_260-LED_QRG_Rev-02-1-30-12DEC.pdf
https://www.chauvetprofessional.com/wp-content/uploads/2015/07/Q-Spot_260-LED_UM_Rev-02-1-30-12DEC.pdf

DMX is a similar 8-Bit architecture.
to control multiple DMX lights, they must be split in channels...

if i have 1 machine with 8 channels, and 2 with 16 channels...
one possible DMX configuration is:
1-8 HW1
9-25 HW2
26-42 HW3.

the number of channels each machine uses is fixed, some activate or deactivate advanced mode, 8-channels basic, and 8-optional.
but the value/number of the channel group is dynamic,
and the order of the channels is continuous.

SCSI uses 1 Channel = 1 Machine.

Using same HW layer as MIDI, but different compatible protocol...
some MIDI interfaces are Not multi-client,
that means if you have Protools or Cubase or Logic, or Ableton, etc...
the MIDI interface is busy...
and cannot be shared with other softwares,
assuming the HW control software is Stand alone,
but that depends on the MIDI interface driver design...
RME hdsp 9632 MIDI interface i think is multi-client...

real midi ports are definitely better than USB Midi ports.
Lan rtpMIDI is definitely better than USB Midi ports.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: zamproject on March 08, 2019, 12:13:15 PM
DPOT is 8-Bits, 14-Bits is Overkill

the logic thing to do, is to use 2x CCs for 1x DPOT,

That's exactly what do RPN/NRPN...
+two CC to set the NRPN number

you end with 16384 parameter of 14bit (16384steps) that's what midi can do since decades (if manufacturer/developer bother to fully implement midi spec...)

Some Dpot go up to 10bit... NRPN do it easy with stepped LSB  (MSB  0 to 127 + LSB 0/15/31...111/127 ) or non full scale use of first 1024 value (MSB+LSB from 0 to 1023)

Best
Zam
Title: Re: Open Source Digitally controlled Analog Project...
Post by: iampoor1 on March 08, 2019, 12:29:21 PM
Yes...14 bits is overkill, but 8 bits is underkill. VCA's can have a much finer resolution than a DPOT, and Dpot resolution is surely going to improve with time. Many DPOTs go up to 10bits already. If you are trying to build a "standard" do not start with the absolute minimum resolution when implementing a 14bit interface is not much more work! :)
Title: Re: Open Source Digitally controlled Analog Project...
Post by: mhelin on March 08, 2019, 02:19:20 PM
I don't understand why you still consider MIDI (vs.  OSC). OSC would be much better fit in this kind of use case which is to control analog devices. Like there's tons of software which to integrate easily. For an example check these free SW libraries:

OSC VST bridge:
http://oscvstbridge.sourceforge.net/
-VST plugin for OSC

https://github.com/CNMAT/OSC
- Arduino and Teensy OSC library

TouchOSC:
https://hexler.net/software/touchosc

Grab those, and what ever hw control mechanism (VCA, digital pots etc.) you ever want to use you can implement using Arduino or Teensy board connected to your HW and control, at least on prototyping level, using the above VST plugin. I think Ableton Live specially has good support for OSC (https://www.ableton.com/en/packs/connection-kit/ etc.). MIDI is outdated, it's OK for playing keyboards but not for much else. OSC uses similar resource based  URL's as all web applications today (which use REST API's). So the OSC API itself descibes the parameters and resources that can be controlled in cleartext format, for MIDI you need complex MIDI implementation charts and hundreds of pages of documentation telling which RPN/NRPN control which parameter on HW. Also the whole OSC ecosystem is growing all the time, for MIDI application you have to dig a lot to find anything usable.

E: The VST plugin above might not be the solution for current 64-bit DAW's but you get the idea anyway. Also regarding the datatypes the basic OSC datatypes are 32-bit fixed or floating point number for and example, or strings. There's simply no rationale in thinking how many bits to use, seven, 14 or something else, just send some numbers.

Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 08, 2019, 10:17:31 PM
Non-Invasive solutions already been done:
https://yostlabs.com/servo-center/

USB to Servo,
MIDI to Servo.
$100us. each.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: gyraf on March 09, 2019, 03:19:31 AM
Look again.

It's not the servos that present the problem (I diy'ed my first working cnc-machine around 1999), but the universal mechanic interface to pots and switches. 

You should really do a working and universal mechanical model before starting worrying about resolution and software. All that is already done, as you see from previous comments..

Jakob E.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 12, 2019, 12:57:03 AM
Non-Invasive CONS: too expensive...

The fastest Servo from Futaba BLS-276SV $180usd. + SH
GearBox to convert 90° to 360° $100usd. + SH  "but only works well with servos that can be reprogrammed."
https://www.servocity.com/bm-400-400-servo-gearbox

Cheapest Linear Servos $90usd. + SH
https://www.servocity.com/servos/linear-servos
Pro Linear Servos $300usd. + SH

Controller Board MIDI to 16-Servos $81usd. + SH "Expandable"
https://yostlabs.com/product/servocenter-midi/

to convert / digital control 16 Pots a "A Basic Analog Rack"
============= $4561usd. + SH Parts Only, more are needed, probably ~$5kusd.

The Gear Box cannot be avoided,
using a slower / cheaper servo can also work.

Slowest Standard Size Futaba S9151 Servo: $90usd. + SH
x16 = $1440usd. + SH
+ 16x Gearbox = $1600usd + SH
+ MIDI Controller
======== $ 3121usd. + SH for 16-pots.

Speed & Accuracy is important with multiplier Gearbox.

purchasing fake Futaba, saves cost, but are Not as accurate, they shake like Parkinson, some ACME brands are very good.
Futaba cost is prohibitive...
there are others more "price / performance" balanced ratio,
Fastest to Slowest:
Futaba BLS-276SV $180usd. + SH https://www.servocity.com/bls-276sv-servo
Futaba S9254 Servo $110usd + SH https://www.servocity.com/s9254-servo
Futaba S9452 Servo $85usd + SH https://www.servocity.com/s9452-servo
Futaba S9151 Servo: $90usd. + SH https://www.servocity.com/s9151-servo

Savox are way cheaper, $32usd, the slowest $65usd. the fastest.
https://www.servocity.com/sc1258tg-standard-size-coreless-digital-servo
Speed, Accuracy, Repeatability & Reprogramable is Unknown.

Hitec servos, depends, can be cheaper than futaba or more expensive.
some do Not work with Standard PWM signals...
Quote
The PWM range for this servo is 760 ~ 1020 usec. It will not work with servo controllers that transmit a standard PWM range (1050-1950usec). Hz Refresh rate: 200~560 Hz.
like the: https://www.servocity.com/hsg-8315bh-servo

The slowest Standard size servo from Hitec $60usd. + SH
https://www.servocity.com/hs-645mg-servo

Some have Back flow current, that requires a PAD in the circuit:
Quote
PLEASE NOTE: While compatible with most radio control devices, the regenerative braking feature of the HSB-93XX series servos may cause a problem if the device cannot accept a backflow of current. The types of devices that cannot accept this backflow are: Voltage Regulators, Power Safe Receivers and certain BEC circuits whether stand alone or integrated within an Electronic Speed Control. Check with the manufacturer or the Hitec website for a list of compatible models. If your device cannot accept a current backflow, then you must install a PAD (Power Absorbing Device - Hitec PN# 55756) as described in the manual. A PAD is included with every Hitec brushless servo.
like: https://www.servocity.com/hsb-9360th-servo
$210usd. + SH

https://www.servocity.com/hs-7940th-servo
$150usd. + SH

while its a nice idea, it becomes price prohibitive / too expensive..
PROS:
 can be purchased piece by piece, upgraded piece by piece, a big investment to start is Not required.
Different kinds of servos can be mixed, some are more important / critical than others.
Input & Output gains speed is usually Not important, but precision is.

to be continued=?...
Title: Re: Open Source Digitally controlled Analog Project...
Post by: zamproject on March 12, 2019, 09:59:20 AM
Standard PWM signals...

Hello

Did you ever try to install a PWMed motor in an audio device ?
You'll have issue with noise...

Best
Zam
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 12, 2019, 10:13:36 AM
Hello

Did you ever try to install a PWMed motor in an audio device ?
You'll have issue with noise...

Best
Zam

Non-Invasive = Outside the Box,
the Box is usually metallic / electric conductive.
the Box is usually connected to Ground.
= https://en.wikipedia.org/wiki/Faraday_cage
Title: Re: Open Source Digitally controlled Analog Project...
Post by: dirtyhanfri on March 14, 2019, 03:45:57 PM
Even being out of the box, it doesn’t seem the most efficient solution.

I think Wes Audio has a nice solution for this, they even adapted it to a classic design as the 1176 compressor.

Wes Audio protocol is kind of open, I don’t recall the exact conditions but I got some tech documents easily.

I think RJ45 or even wireless is the way to go if we’ll deal just with control signals and keep audio analog. WiFi or Bluetooth antennas are cheaper than cool vu meters nowadays.

I have some clear ideas about where would I go with this, just need time to study...
Title: Re: Open Source Digitally controlled Analog Project...
Post by: taczowbes on March 18, 2019, 01:22:28 AM
Perhaps the best way of looking at this is to think of the software implementation as one cohesive standard that could then suit various hardware control systems from various makers and manufacturers.
These systems have become more and more popular over the years and having a standard for them wouldn't be unprecedented. If we could supply an open software standard and create a few hardware implementations (some more invasive than others, some which could be built in to hardware at the design stage, etc) people might find a total recall system worth it.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 20, 2019, 12:24:50 PM
Perhaps the best way of looking at this is to think of the software implementation as one cohesive standard that could then suit various hardware control systems from various makers and manufacturers.
These systems have become more and more popular over the years and having a standard for them wouldn't be unprecedented. If we could supply an open software standard and create a few hardware implementations (some more invasive than others, some which could be built in to hardware at the design stage, etc) people might find a total recall system worth it.

To me thats called MIDI or Ethernet...

anyway...
Part 3... converting Real VU/Led Meter signal to Digital MIDI or Ethernet data, to make a VST AAX or Stand alone GUI with true VU/LED signal from the Real Analog HW, with minimum latency.

Most VU Meters are 90° and Current type, Not voltage type...

goal #1. is to measure the voltage & current of the VU meter,
without affecting the VU meter...
that means very high impedance 1Meg ohm minimum, 10M better.
circuit will be similar to a hi-end DigitalMultiMeters.

https://www.youtube.com/watch?v=JbCI4Lsnqho
https://www.youtube.com/watch?v=wbRx5cQZ8Ts
http://www.tonnesoftware.com/meter.html
https://www.youtube.com/watch?v=4U-nxdp-LDw
https://www.youtube.com/watch?v=6obMgUC5FKs
https://www.youtube.com/watch?v=7OLGswQ7ICI

----
DMM
https://youtu.be/yuCXsT3_WRE
https://youtu.be/UKIzhz0XLaQ
https://youtu.be/g3uYcHAumhA
https://youtu.be/6j8i3LfKm5A
https://youtu.be/e9cpKN69Avk

goal #2. to use common / low price AD converters...
8-Bit 256 steps for 90° could be good enough.
0.3515625° per step, but MIDI CC has 7-Bit = 0.703125° per step..
MIDI also allows 14-Bits but its over kill for an 8-BIt AD.

Candidate #1: YL-40 board with Philips / NXP PCF8591T
PROS:
has:
4x AD
1x DA
SCL
SDA
GND
VCC
Temp, Light, Manual Pot Volt meter. "probably will never be used."

problem/Cons: is 3.3vdc.
most analog hardware works at +15/-15vdc, VU meters are Rectified DC witha Schoky or fast Diode 4148 glass type.

the voltage resistor / divider network circuit requires very high-quality precision resistors.


Part 4.. Building a Relay Network Matrix. "like a 12v Relay FPGA."

Candidate #1: 16-Channel Relay Module.
https://einstronic.com/wp-content/uploads/2017/06/Relay-Modules-Catalogue.pdf
there are 2 versions of the board, one comes with a 12v to 5v buck converter,
the other, the buck converter is unpopulated in the PCB, apart from that, are exactly the same.
the populated version requires +12vdc for the Mechanic Relays & +5vdc for the Opto Couplers and the Darlingtons to puch the Relays.
the unpopulated version comes with +5vdc Relays, JQC-3FF-S-Z

why mechanical vs. solid state like: omron g3mb-202p
or other CMOS, JFET, or BJT ?

mechanical guarantee absolute signal integrity... some BJT affect signal...
must have very low on resistance if Solid, like IRF510,.

alternative a Vacuum tube switch matrix maybe can also be done, for fun... like a Thyratron or a SCR.
https://youtu.be/ygg04-DIXj4?t=352

PROS: High switching speed Not required.

The Matrix is required to Route any analog or digital signal, like a Remote Controlled Patchbay...
like Solid State Logic SSL X-Patch,
but the problem with SSL X-Patch is that signal path is Not passive, its Active and has Audio Buffers at the input. "Op-Amps"
that does Not allow to route any signal,  like AES/EBU, Wordclock, microphone, turntable. for example.

if the Matrix Relay is done with MIDI & Ethernet, the Ethernet port maybe can be designed to Emulate  SSL Ethernet port,
and may be compatible with SSL software.
http://sslweb.solidstatelogic.com.s3.amazonaws.com/content/x-patch/XLogic_X-Patch_Install_Guide.pdf
http://sslweb.solidstatelogic.com.s3.amazonaws.com/content/x-patch/XLogic_X-Patch_User_Guide.pdf
http://sslweb.solidstatelogic.com.s3.amazonaws.com/content/x-patch/X-Patch_Remote_MAC.zip
http://sslweb.solidstatelogic.com.s3.amazonaws.com/content/x-patch/X-Patch_Remote_PC.zip
http://www.solid-state-logic.co.jp/docs/X-Patch_Flyer_jpn.pdf
http://www.solid-state-logic.co.jp/music/Xlogic%20X-Patch/images/X-PATCH_Performance_large.jpg
http://www.solid-state-logic.co.jp/docs/X-Patch_connections.pdf
http://www.solid-state-logic.co.jp/music/Xlogic%20X-Patch/images/X-PATCH_16_CH_Inserts_large.jpg

its a 16x16 Patchbay, but software allows to control 6 units more.
https://www.barryrudolph.com/mix/sslx-patch.html

Ethernet Shield v1 with W5100 is required because  W5100 doesn't come with a pre-assigned MAC address.-
Ethernet Shield v2 with W5500 is No Go.
there are other Ethernet modules like: ENC28J60 with SPI interface, but MAC address is unknown.
https://github.com/njh/EtherCard
https://www.instructables.com/id/Arduino-Webserver-Controller-Using-Ethernet-ENC28J/
https://blog.japaric.io/wd-4-enc28j60/
https://www.luisllamas.es/arduino-ethernet-enc28j60/
http://ww1.microchip.com/downloads/en/devicedoc/39662e.pdf
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 20, 2019, 04:33:59 PM
.
Part 3... converting Real VU/Led Meter signal to Digital MIDI or Ethernet data, to make a VST AAX or Stand alone GUI with true VU/LED signal from the Real Analog HW, with minimum latency.

Most VU Meters are 90° and Current type, Not voltage type...

goal #1. is to measure the voltage & current of the VU meter,
Wrong; although VU-meters are indeed current devices, they are used to measure voltage. You want to know the amplitude of the audio signal, you measure its voltage. Now VU-meters are obsolete in the context of digital recording. You want Peak-meters.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 20, 2019, 05:50:30 PM
other Matrix with Total Recall is the:
 https://www.tegeler-audio-manufaktur.de/Konnektor_analogue_mastering_matrix
more advanced that SSL X-Patch...
https://youtu.be/WnW367c5unw

https://www.tegeler-audio-manufaktur.de/Schwerkraftmaschine_der_Kompressor
has Motorized Pots.

https://www.tegeler-audio-manufaktur.de/News/Why-We-Chose-Ethernet-instead-of-USB-FireWire-Thunderbolt-MIDI

(https://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Multigrade_operator_XOR.svg/1270px-Multigrade_operator_XOR.svg.png)
(https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Z2%5E4%3B_Cayley_table%3B_binary.svg/1127px-Z2%5E4%3B_Cayley_table%3B_binary.svg.png)
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on March 20, 2019, 06:36:26 PM
Wrong; although VU-meters are indeed current devices, they are used to measure voltage. You want to know the amplitude of the audio signal, you measure its voltage. Now VU-meters are obsolete in the context of digital recording. You want Peak-meters.

#1. This thread is about mimic a Real Analog Hardware User Interface including VU meters if Real HW Has,
with a Digital Graphic User Interface in VST, AAX, or stand alone.

Not about cheating  Vu Meters, its about measuring the Real Hardware VU Meters "if has", in Real Time and display the exact value as close as possible "within digital limits", the Real Hardware with a GUI inside a DAW.
to allow Analog Hardware to be Digitally Controlled with GUI feedback..
---
#2.
ive done tests with different DAWs, Protools HD 10, & HD12.7, Logic 9, Cubase/Nuendo3/4, VSTHost, Ableton, Samplitude, Cakewalk Sonar, etc...
3rd party plugins from Waves, PSP Audioware and others,
and Digital Hardware like Tascam DM-3200 digital console with Real Leds meter bridge ...

most Software Meters are useless.
Logic 9 the worse...
Tascam digital console, the best ive seen.
to me software are Not close to real hardware...

i haven´t done test with Waves Durrough Meters, they claim they are exactly the same, with side by side video...
but Waves VU, Not as good to real hardware.

PSP Audioware Triple Meters are very strange, the needle jumps, like if the screen has 15frames per second, very weird,  like Midi 7-Bit jumps.
Logic 9 meters are so bad its mind blowing, compared to Tascam digital console real Led meters... with same signal, its mid blowing.
---
#3.
i know there are more Advanced Digital meters, like Dynameter, TC Electronics LM, etc...
https://youtu.be/HW8Te1KqZrg
https://youtu.be/rQa6xOo-xEs

https://youtu.be/3Gmex_4hreQ
https://youtu.be/scfmFbA3DwA?t=125

to me Real Vu Meters are more important Now than ever/never...
Title: Re: Open Source Digitally controlled Analog Project...
Post by: cyrano on March 20, 2019, 08:47:22 PM
I've got a bunch of motorised faders and encoders ready for a project similar to this. I've experimented a bit with various mixers. Keeping motor noise out of the audio isn't easy. And keeping PWM out of the audio seems next to impossible if you replace normal faders in existing gear with motorised ones.

The talk about servo's gave me an idea. Take an ESP8266, a Lipo battery and a reasonably strong mini servo. Add a few FETS for a H-bridge. Put into a case, with a rubber snap-on for the usual knobs. Could work for externals, is reasonably universal, as long as you have different rubbers. Won't break the bank...

Even cheap enough to build several.

Only problem is: How do we keep them in place?

Rubber bands? Clamps? Suction cups? Framework? Magnets?

Magnets seem interesting, until you consider they don't work on aluminium fronts...
Title: Re: Open Source Digitally controlled Analog Project...
Post by: abbey road d enfer on March 21, 2019, 12:56:39 AM
#1. This thread is about mimic a Real Analog Hardware User Interface including VU meters if Real HW Has,
with a Digital Graphic User Interface in VST, AAX, or stand alone.

Not about cheating  Vu Meters, its about measuring the Real Hardware VU Meters "if has", in Real Time and display the exact value as close as possible "within digital limits", the Real Hardware with a GUI inside a DAW.
to allow Analog Hardware to be Digitally Controlled with GUI feedback..
So you want your software to mimic the errors of a mechanical VU meter. What's the use?

Quote
most Software Meters are useless.
Often the reason is that graphic tasks are given a low priority compared to audio.
I use the meters of the Tascam DM4800 and I find them useful, although they don't show intersample overs. The meters in Samplitude or Reaper are just signal presence indicators.

{quote] i haven´t done test with Waves Durrough Meters, they claim they are exactly the same, with side by side video...
[/quote] They may be, but what's the point? VU meters are inadequate in the context of digital audio.

Quote
i know there are more Advanced Digital meters, like Dynameter, TC Electronics LM, etc...
Most of these meters are designed to provide more useful and more adequate information than a mechanical VU-meter. They are mostly designed to provide quasi-peak information.

Quote
to me Real Vu Meters are more important Now than ever/never...
Important in what respect? What is the unique information they give? I've had my share of dealing with VU-meters; after 50 years of using them, I admit they're good for two things: alignment of equipment using steady tones, and as a crude indicator of signal presence.
Title: Re: Open Source Digitally controlled Analog Project...
Post by: JohnRoberts on March 21, 2019, 10:18:04 AM
I agree with Abbey as usual.

The Dorrough meters  were inspired (cough) by my patented Peak/VU meter system (US04166245  Roberts 1979). Dorrough changed the nomenclature and curved the display to finesse infringement of my earlier patent that used a straight line display and plainly described the signal attributes (peak/ave).

Peak and average can both be important signal characteristics to separately manage headroom and relative loudness while mixing.

VU meters are more fun to look at. I even put twenty four plus old school VU meters in one AMR console meter bridge (1990s), because the customer is always right, even when wrong.  ::)

JR
Title: Re: Open Source Digitally controlled Analog Project...
Post by: Juanpcdiy on April 25, 2019, 12:48:28 AM
Update:

was testing in ProTools the speed of "generic servo MG996R" http://www.towerpro.com.tw/product/mg996r/
there are 2 versions, 1 continuous "360º", the other Range Limited to 120º, BUT... physically can go 180º..
thats problem #1.

Problem #2. is that the Servo Midi v1.2 Board, has a LM1084 5Amp Regulator, BUT... does Not have current limiting resistors on each Servo Output...

i had only 1 servo connected receiving the full 5Amp load...
Servo MIDI Controller Default Range is 0-127, cc114 cc115, BUT... that range forces the MG996R Servo to go beyond 120ª, beyond 180º
When Servo is forced to Hard Limit, overheats and burns...
was sending a 1010101010111111 Midi signal

i thought the servo had an internal built-in current limit resistor inside, or some kind of protection, but does Not...
thats why is so cheap. LOL Jajajajajajaja lasted 5 minutes.

the Servo datasheet says its designed for 500mA, x16 = 8Amps.
but LM1084 is 5A
the solution would be to install LT1083 that has more current, but small heatsink, also needs to be improved.
the LT1082 is 5 pin Not compatible.
but the Board can also be used with external power, and disable internal servo power, but the external power input connector does Not feel bold / robust enough, as only source, as helper is ok.

purchased another servo, ohm resistance is: 2.3ohms aprox. burned servo shorts the motor 0.ohms.

the Servo Midi board is based on ATMega8515L
but code has some problems...

allows Servo Output s0 to be Midi controller by cc0 in Low Range jumper Setting, and cc16 in High Range Jumper Setting...
But ProTools HD12,7 Does Not allow cc0, only from cc1 in  Automation... Edit window.
to draw automation, can only be used from servos 2-16  "s1-s15" OR... jumper must be changed to High setting cc16-cc32 in the pcb...
that is a No go, code must be modified for ProTools...

Add/Remove Controller from the controllers submenu Range Goes from cc1-cc119 for Automation... in Edit mode.
Midi Event List can edit all the missing controllers.

maybe creating a custom Midi controler in OSX Midi Studio... maybe...