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Voltage Controllers as MIDI pitchbend sources??
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Author Voltage Controllers as MIDI pitchbend sources??
Rex Coil 7
November 24th, 2018: The title of this thread used to be "Squarp Pyramid CV converter to CC question (range)??". However, the discussion twisted and turned to focus more on how to go about converting control voltages to MIDI pitch bend (which was pretty much all of my own doing). That said, I've changed the title of the thread to "Voltage Controllers as MIDI pitchbend sources??" because it's far more relevant to what the overarching discussion veered off to.

End.


*********************************************************

The "Pyramid" MIDI sequencer (made by a French company called Squarp) has a CV input. Control voltages can be converted to CC messages.

My question is regarding CC range.

Think of a CV pitch wheel. If I send the Pyramid's CV input 2 volts positive (wheel UP) and 2 volts negative (wheel DOWN) how do I configure that in the Pyramid to be MIDI CC pitch up and MIDI CC pitch down, just like a regular pitch wheel would operate? The Pyramid manual is unhelpful regarding this issue.

Some MIDI gadgets offer a means of sending "positive" and "negative" CC message with ~0~ being in the center. I'm not sure if the Pyramid is capable of doing this, since the manual is so vague.

I want to use a modular synth pitch wheel (Dot Com Q181W specifically) as a pitch wheel for my MIDI synths. The Q181W sends positive and negative voltage, depending on where the wheel is positioned. In the middle of it's sweep it sends no voltage. Spin it up and it sends positive voltage, spin it down and it sends negative voltage. Springs keep it centered in the "no voltage sent" position.

Any ideas or experience on this matter?

help
Panason
Pitch bend is not a CC message - it has a much higher resolution than CC messages and so they would have had to use a higher res AD converter to give you pitch bend from CV without audible stepping. I'm guessing it's a no go.. Just use a MIDI keyboard?
Rex Coil 7
Panason wrote:
Pitch bend is not a CC message - it has a much higher resolution than CC messages and so they would have had to use a higher res AD converter to give you pitch bend from CV without audible stepping. I'm guessing it's a no go.. Just use a MIDI keyboard?
Then why is the pitch wheel listed as a modulation source and the pitch bend is listed as a modulation destination in every digital MIDI synth I own in their MIDI implementation charts and list of modulation sources and destinations? I'm not trying to be a sarcastic prick, the question is genuine.

Let's start with this .... Here's a link to the Doepfer Pocket Electronics kit manual. Towards the end of the manual it describes sending NPRN signals, as well as CC signals. I'm ignorant regarding all of this (precisely why I've posted this thread in the first place ... right?).

LINK = http://www.doepfer.de/pdf/PE_Man.pdf

Second (just for anyone's information) ... the Synthesizers.Com QKB61 is a MIDI keyboard controller. However it is not outfitted with a pitch bend wheel or modulation wheel. "Just use a MIDI keyboard" .... while that may be easy enough for you to do (cough up the money that easily) I'm going to look for another alternative.

For me to do that;

*** First, sell the Dot Com kybd.
*** Settle for another MIDI keyboard that has a second rate keybed just to have a pitch wheel.

Yea, see, that doesn't work for me. I'm not willing to trade off an excellent keybed for a pitch wheel. This is why I'm looking for alternative ideas. I've even tossed around buying one of the other brands of MIDI keyboards, chopping off the controller section, mating that with the Dot Com keybed, and then having my damned cake! I have, in the past, actually removed the keybed from an Arturia Keylab MkI (mark one) controller and then connected up the control section to other MIDI stuff using just standard MIDI cables and it all still worked. But in this example that would cost me $500.00. It may be a viable option ... emphasis on the word "may". I've been known to take a saw to things before (such as four Microbrutes that I chopped the keybeds from, and the Keylab 25 that I removed the keybed from) ... so you just never know what I'll do next! By the way, that Keylab 25 chop ... the keybed went right back on without any hassles ... just a few screws and it all went back together.

My point is that removing the keybed from the control section and still having an operational control section works ... at least with some Arturia products. Here's one idea .....

Arturia Keylab MkII 61 key ....





Arturia MkII 61 key controller section with the stock keybed removed (altered image).





I used the term "CC" because I am lazy and didn't care about being that technically correct when I described all of what I want. I just want to learn about building my own MIDI controller. It really comes down to just that.

seriously, i just don't get it
ranix
A midi CC only has 128 possible values. I'm not sure why, it might be because some MIDI messages can go negative (127 is the max size of a signed 1-byte integer).

Since 127 steps isn't enough resolution for pitch bend, two bytes are combined together when pitch bend messages are sent. So where a CC is usually two bytes (cc number & channel on first byte, value on second byte) the pitch bend is 3 bytes (cc nuber & channel on first byte, value most significant byte on next byte, value least significant byte on next byte). The two value bytes are combined to create a 16 bit signed value to use for pitch bend.

This is similar to how instrument select messages work too.

Some synthesizers may internally slew limit pitch bend, aftertouch, and mod wheel messages after receiving them over midi to smooth them.
Rex Coil 7
ranix wrote:
A midi CC only has 128 possible values. I'm not sure why, it might be because some MIDI messages can go negative (127 is the max size of a signed 1-byte integer).

Since 127 steps isn't enough resolution for pitch bend, two bytes are combined together when pitch bend messages are sent. So where a CC is usually two bytes (cc number & channel on first byte, value on second byte) the pitch bend is 3 bytes (cc nuber & channel on first byte, value most significant byte on next byte, value least significant byte on next byte). The two value bytes are combined to create a 16 bit signed value to use for pitch bend.

This is similar to how instrument select messages work too.

Some synthesizers may internally slew limit pitch bend, aftertouch, and mod wheel messages after receiving them over midi to smooth them.
"Some synthesizers may internally slew limit pitch bend, aftertouch, and mod wheel messages after receiving them over midi to smooth them".I already understood that much. It's also precisely why I reject the notion that CC "cannot" be used for pitch wheel function. Until I see some sort of absolute that says "all synths" ... and "cannot" ... and "do not"... use CC for pitch bending, I'm still open to the idea. (And thank you for your help, Member *ranix ... I don't wish to appear ungrateful.)

But we're kinda off the tracks here. Well, a little. The Pocket Electronics setup by Doepfer may indeed provide NRPN signals (or some type of "signal slewing"), which is why I posted the link to the PDF manual so that people more educated than I can have a look.

I know I need to learn more about all of this, which is (in fact) what I am attempting to do here in this thread. Ya gots ta ask questions if ya wants any answers.

I have a Squarp Pyramid digital sequencer, a Nord Micro Modular, three E-MU Proteus family rack synths, a modest pile of analog CV gear, and the ability to build my own passive/active controllers (as in DIY skills). I need to learn how all of this CC, SYSEX, and NRPN stuff works, what functions need which type of control, and where sources of those signals may be found. This thread is part of that process.

There are several CV-to-MIDI (please read that carefully, CV to MIDI ... not MIDI to CV) converters available presently. Kenton, Doepfer, and ADDAC seem to be the most proficient of the manufacturers offering such gear. So between the MIDI/Digital synths I have, the analog controllers I have, and the converters that are offered by the three manufacturers I listed, I need to learn how to make my own controllers so that I may break free from having the rely on commercially made MIDI controller gear (as in the various MIDI controller keyboards and the MIDI sequencers made today).

See my plan there? nodnod
ranix
Yeah I've been down this road recently myself. That's what I've been doing with the Atari and all that stuff. I'll share some information you might find useful/interesting:

I decided I don't care much about controlling outboard synths with the modular. I have one q172 quantizer aid I can use to send pitch/gate sequences out to the Atari with via MIDI, and I use the Beatstep Pro to receive a clock from the modular & convert the clock to MIDI clock and send that over to the Atari so I can sync it to the clock from the modular. Then the Atari will step in time with the q960 or whatever so I can just hit record and grab some sequences. Then I edit them in Cubase and play them back over the Polyend Poly (with 3.5mm to 1/4" cables) or any MIDI synth. A couple button presses switches me over to driving the modular from the Atari again. I can still edit the sequences in real time and I still have 1 dedicated MIDI channel with knobs so it works fine. Although if I run the clock on the modular too fast it will crash the MIDI adapter! (but that's very fast)

For drums, usually I'm just pinging filters (because I have lots of filters :3 ). I usually trigger very boring and uninspired patterns from the beatstep pro or directly from the clock signal with a divider, but I just got a euclidean rhythms module I'm looking forward to playing with. There's a standalone device called the ddrum ddti that should be able to convert these patterns to MIDI too which I have in the mail. This thing seems to take 10 trigger inputs and convert them to notes, where each input is its own dedicated note. It looks like you can program it a little bit so maybe it's configurable. I'll know more about that next week.

I've been using three MIDI devices as my primary inputs, each of which I can direct to any instrument or combination of instruments through Cubase in the Atari. I don't have to think about outboard devices much because the mod and pitch bends just work, since they start and end on MIDI devices. One thing I am missing is a dedicated controller for the fx unit, like a leslie switch or something I can put on my primary keyboard controller.

For expressive sounds in the modular, I don't bother with MIDI. I just have a wind controller that generates CV directly.

I like to use https://www.pjrc.com/teensy/ devices for experiments with MIDI, I have the most experience with the teensy 2.0. I think they are easy to program, but I have significant experience with C and computers in general. There is a whole MIDI library with tutorials if you're interested in learning how to make your own realtime MIDI processors and routers.
ranix
oh yeah and this thing is awesome, if you ever see one of these grab it and don't let it go. It's a cv->midi box with cool pedal effects and pitch/gate/velocity/bend inputs (!!)




Panason
Rex Coil 7 wrote:
"Some synthesizers may internally slew limit pitch bend, aftertouch, and mod wheel messages after receiving them over midi to smooth them".I already understood that much. It's also precisely why I reject the notion that CC "cannot" be used for pitch wheel function. Until I see some sort of absolute that says "all synths" ... and "cannot" ... and "do not"... use CC for pitch bending, I'm still open to the idea.



It's just how MIDI is specified. There are different types of MIDI messages (or MIDI events). Pitch Bend is one, CC is another. MIDI synths just don't offer the option to do pitch bend with MIDI CCs because Pitch Bend is so much better for the job.
The dedicated CV-to -MIDI converter is the best solution here as you've figured out.
ranix
There's something I found that looks like there is a "pitch bend" option in the CC menu, after all the numerical CC, even though pitch bend itself isn't a CC. But, this is for setting a knob on the Squarp, not for the incoming CV. Maybe the incoming CV has the "pitch bend" option hiding after the numerical CC too?

Rex Coil 7
This may provide the needed circuitry to make pitch bending happen using an active pitch wheel to do up/down bending on digital MIDI gear ....

LINK to WEB PAGE = http://www.kentonuk.com/products/items/m-cv/pcvmidi.shtml

LINK to PDF MANUAL = http://www.kentonuk.com/kmanualspdf/pcvmidi-manual.pdf

They sell for $235.00 in the USA. seriously, i just don't get it

So, Dot Com Q181WP ($145.00) sending voltage to the Kenton Pro CV to MIDI ... then MIDI to my E-MUs and/or Nords.

I've written Kenton, waiting on a reply. thumbs up

(Haahaa ... internet radio playing "Cherry Bomb" by The Runaways .... hello daddy ... hello mom ... ch ch ch ch ch ch ch CHERRY BOMB!) lol
Rex Coil 7
Unbelievable. I wrote to Kenton yesterday, explained what I want to do (use the Dot Com Q181WP pitch wheel to do pitch bend on digital MIDI synths). The guy writes me back telling me that the pitch wheel needs to send out "1v/oct".

WHAT IN HELL?

An analog pitch wheel just sends out voltage. It's not calibrated. It just sends out either positive or negative voltage depending on which way it's rolled (up or down). It's 100% up to the destination device what it does with that voltage.

So, I wrote them/him back ... I attached the Datasheet for the Q181WP to the message and asked that they/he kindly read the datasheet and then let me know if the Kenton Pro CV-to-MIDI converter will do what I want.

Since today is Friday I most likely won't hear back until Monday at the earliest.

Great googly moogly! An analog pitch wheel that has to put out "1 volt per octave" .... seriously? How does that work?

lol
Rex Coil 7
Orrrr .... there's this option ... Doepfer Wheel Electronics (not the same as the Pocket Electronics) ...

LINK TO ANALOGUE HAVEN PAGE = http://analoguehaven.com/doepfer/wheelelectronic/

LINK TO WHEEL ELECTRONICS MANUAL = http://analoguehaven.com/doepfer/wheelelectronic/manual.pdf

LINK TO PASSIVE JOYSTICK (B10K) = https://www.ebay.com/itm/Joystick-Potentiometer-JH-D202X-R4-10K-2-axis -Sealed-PTZ-Thermistor/252084169392?epid=1831709709&hash=item3ab1632ab 0:g:L5wAAOSwHjNV7dUv:rk:36:pf:0

The joystick is just an example ... I have six of the B10K joysticks on hand (two spring loaded, four un-sprung).

From what I can tell, this particular Doepfer kit is set up for dealing with actually doing pitch bend using a passive controller. "Zero center" is part of the capabilities, as is the all important UP bending and DOWN bending ... all converted to MIDI signals.

Does it work? Hell, I don't know!

Someone MUST make something of this sort. I mean, there's mighty heaps and piles of MIDI controller keyboards with pitch bend wheels ... so there's got to be someone that makes just the circuitry that gets that done. I don't care if it requires a passive controller (like a spring loaded passive B10K joystick, for instance) .... or an active analog controller (like the Dot Com Q181WP which puts out positive and negative voltages).

Hold up hold up hold up .... Actually, I do care. If I can work out one of the active voltage source "CV to MIDI" type options that would open up the situation to not only pitch wheels and joysticks .. but also the wonders of the Dot Com 20 inch ribbon controllers!! Wouldn't a MIDI keyboard controller like this be cool AF? .... dual ribbons, joystick, aftertouch, attack velocity, release velocity (that's the one I made up for my modular synth named "The Super"). Beneath it is the dual manual variant just for kicks.






Ugh! This is so frustrating! DAMMIT I hate being ignorant!

Vocational education is SO important (I'm speaking to any of you college kids reading this) .... the fact that vocational classes are barely offered in public high schools is bad enough ... but all of these college kids taking courses in goddamed "gender studies" and "social justice" .... that shit is useless. Ok, rant completed. I feel like I just took a big old satisfying emotional shit!

Alright then, I simply must learn more about all of this CV to MIDI stuff. I feel enslaved and dependent upon what vendors provide as information. That makes me vulnerable to bullshit and can make a person a prime target for having his wallet fleeced.

I need to sort all of this out. Sift through these options (Pyramid .. Doepfer Wheel Electronics .. Kenton Pro CV-to-MIDI .. Doepfer Pocket Electronics .. ADDAC221). I just know the answers are before me. It's a matter of educating myself and selecting the best course of action!

I just want to make a bloody pitch bender for my MIDI synths!

thumbs up
Rex Coil 7
ranix wrote:
There's something I found that looks like there is a "pitch bend" option in the CC menu, after all the numerical CC, even though pitch bend itself isn't a CC. But, this is for setting a knob on the Squarp, not for the incoming CV. Maybe the incoming CV has the "pitch bend" option hiding after the numerical CC too?

Sorry, I missed this reply.

Y'know ... I have no idea. That manual is an atrocity. I've actually had to start my own "manual" compiled from notes I've taken during actual use and while watching videos.

Any time you're attempting to explain something and you generate more questions than you answer ... you're doing it wrong.

Redneck

(thanks for pointing out what you located in the manual, ranix ... I know you're trying to help) nodnod
Rex Coil 7
Highly Liquid also makes a "MIDI controller" board ... a DIY thing much like the Doepfer Pocket Electronics and Doepfer Wheel Electronics.

LINK - https://www.ebay.com/itm/Highly-Liquid-MIDI-CPU-Midi-Signal-Generator- Processor-Midi-Controller-DIY/173628363161?hash=item286d0e9199:rk:61:p f:0

I have not located much infos on the Highly Liquid unit yet.

Well, I have the Doepfer Pocket Electronics. I have the Pyramid. I have passive joysticks (six of them) and I have plenty of B10K pots.

I also have my control voltage joystick and a pair of control voltage 20 inch ribbons.

I suppose the thing to do is to start prototyping! I can toss together a few channels of the Doepfer Pocket Electronics in a "test enclosure" and just start goofin' about with some of this stuff. It doesn't hasta bes pretty. It just hasta woik!

(not heard back from Kenton as of yet ... probably not until Monday)

seriously, i just don't get it
Panason
You're a man on a mission!

You should probably ask Doepfer too.... I'd be surprised if Kenton don't have a box that will MIDIfy your dot com keyboard...

Or you could just use that nice Arturia MIDI keyboard you just bought? seriously, i just don't get it

I do agree that the dot com looks all kinds of amazing.
Rex Coil 7
Panason wrote:
You're a man on a mission!

You should probably ask Doepfer too.... I'd be surprised if Kenton don't have a box that will MIDIfy your dot com keyboard...

Or you could just use that nice Arturia MIDI keyboard you just bought? seriously, i just don't get it

I do agree that the dot com looks all kinds of amazing.


On the Squarp Pyramid web page it lists ~inputs~ (quoting) "4x CV in (jack 3.5mm) [0 to 5V]" (end quote).

Well, that settles that, doesn't it! 0 to 5v. Not -5v to +5v. So pitch bend signals coming in to the CV input won't work. At least ~pitch bend down~ anyhow.

Panason wrote:
Or you could just use that nice Arturia MIDI keyboard you just bought? seriously, i just don't get it
It's not mine, it's my wife's.

Besides, I'm not really willing to trade off the FATAR keybed that the Dot Com controller uses for an Arturia keybed with a pitch wheel. I'd be lying if I said doing so hasn't crossed my mind ... a lot. In fact it still is on my mind. But I really need to try to get this worked out first. I'm all about ~modular~. Whether it's a modular bass guitar rig, or a modular synth, or a modular dual Leslie simulation rig, or a modular MIDI controller system. ~Modular~ simply makes a lot of sense to me. If this pitch bend thing can be worked out, I'll be able to put together a truly ~modular~ MIDI controller set up ... made up of the following individual components:

** Dot Com 61 note MIDI keyboard.
** Behringer FCB1010 MIDI foot controller.
** Squarp Pyramid MIDI/CV sequencer and MIDI controller with X/Y pad.
** Doepfer Pocket Electronics 16 part MIDI controller with 128 preset configurations.
** Arturia Keystep (used for transposing sequences and arpeggios, as well as offering a quick and easy 64 note step sequencer and capacitive touch control ribbons).

Sure, a Kurzweil PC3A6 offers most (if not all) of that, including the 61 note FATAR TP/9 keybed (identical to the Dot Com). But it is not "modular" ... it's all in one "box" so to speak. And I've already had that "one box" fail and end up in repair shops for six months out of the last twelve. All because a single component failed, and in doing so that entire list of functions I posted above was not available to me while the controller was at various repair shops for half of a year. Had it been the "modular" MIDI control system I listed above, which ever component was what went bad would have been the only thing I'd have had to do without.

Modular!

Panason wrote:
I do agree that the dot com looks all kinds of amazing.
That's because it is all kinds of amazing.

Panason wrote:
I'd be surprised if Kenton don't have a box that will MIDIfy your dot com keyboard...
I already have a Kenton Pro 2000 MkII. It's what I use to connect the Dot Com kybd to my modular. But that's MIDI-to-CV. If I am to use the tricky little gadgets I've built on to the kybd (joystick, two ribbons) I'll need CV-to-MIDI.

Somehow I think that is what you were getting at when you said Kenton could "midify" my customized Dot Com kybd though. thumbs up

I'm sure readers can understand my frustration here. I mean, it seems like such a straightforward concept ... a means of using some of this wonderful "CV stuff" to do probably the single most basic expressive function ... pitch bend. We have all of these fantastic pitch bending contraptions available in Voltage Controlled format .... wheels, joysticks, ribbons ... and yet it seems like finding hen's teeth when seeking a means to use those devices to bend the pitch of digital MIDI synthesizers. It can't be any more than a PCB any larger than a business card with $10 bucks worth of electronics on it to accomplish the task. Tons of existing MIDI controller kybds already have that little bit of circuitry built into them. All that is needed is to extract that tiny bit of circuit and circuit board and make it in a stinkin' little box.

I'm holding out hope that the Kenton Pro "CV-to-MIDI" conversion box holds that capability. The sales text of the Kenton Pro CV-to-MIDI states the following (quoting) ....

"FEATURES:
*Designed to work with all types of CV inputs
*Super-fast response time
*Famous Kenton build quality
*High specification 16 bit A to D converter and reference for main CV input for rock-steady pitches
*CV/Gate/Aux inputs on 3.5mm mono jack sockets (3.5mm to 1/4" cables are available in our cables section)
*MIDI OUT socket (5 pin DIN)
*Any MIDI channel can be selected
*Switchable for V/oct & Hz/V & 1.2V/oct scaling systems
*Fine tune & scale are adjustable using front panel buttons
*Transpose (coarse tune) - up & down 12 semitones
*Adjustable pitchbend range - up to 48 semitones
*Gate mode selectable V-trig or S-trig
*Auto tune feature for easy setup"

(end quote) I highlighted the relevant information in violet. "16 bit analog to digital converters" (so plenty fine resolution for doing smooth pitch bends). And "adjustable pitchbend range" (which strongly implies their device is configured to do what I need it to do).

So, we'll see once Kenton replies with a cogent answer to my second email to them (sent Friday ... it's presently Saturday evening).

Panason wrote:
You should probably ask Doepfer too...
Sage advice, indeed! I'll wait to hear from Kenton first.

Panason wrote:
You're a man on a mission!
With dogged determination. Because if this "device" is actually not available ... in this age ... it's nearly the year 2020 for God's sake ... then I shall set about doing it myself. There is no reason that this seemingly fundamental piece of conversion circuitry is not available. Especially since digital MIDI synths are on the rise again ("what was once old, is new again"). I can't help but think that a clever person with an Arduino board (so to speak) couldn't work this out.

I'll be taking preorders for empty PCBs, as well as populated and tested PCBs. (wink wink).

lol lol lol
tenembre
ranix wrote:
A midi CC only has 128 possible values. I'm not sure why, it might be because some MIDI messages can go negative (127 is the max size of a signed 1-byte integer).


It's because the MSB designates it as a data or status byte, leaving 7 bits to hold the data.

ranix wrote:

Since 127 steps isn't enough resolution for pitch bend, two bytes are combined together when pitch bend messages are sent. So where a CC is usually two bytes (cc number & channel on first byte, value on second byte) the pitch bend is 3 bytes (cc number & channel on first byte, value most significant byte on next byte, value least significant byte on next byte). The two value bytes are combined to create a 16 bit signed value to use for pitch bend.


CC messages are 3 bytes, not two. 1st byte high MS Nybble designates it as a Control Change message and the LS Nybble is channel. Second byte is the Controller Number, and the 3rd is the value.

Pitch Change is not a Control Change message. It's a different message type. Three bytes - 1st byte is designation and channel, and the second and third bytes are combined for a 14 bit unsigned value (8192 means no pitch bend).
Rex Coil 7
tenembre wrote:
ranix wrote:
A midi CC only has 128 possible values. I'm not sure why, it might be because some MIDI messages can go negative (127 is the max size of a signed 1-byte integer).


It's because the MSB designates it as a data or status byte, leaving 7 bits to hold the data.

ranix wrote:

Since 127 steps isn't enough resolution for pitch bend, two bytes are combined together when pitch bend messages are sent. So where a CC is usually two bytes (cc number & channel on first byte, value on second byte) the pitch bend is 3 bytes (cc number & channel on first byte, value most significant byte on next byte, value least significant byte on next byte). The two value bytes are combined to create a 16 bit signed value to use for pitch bend.


CC messages are 3 bytes, not two. 1st byte high MS Nybble designates it as a Control Change message and the LS Nybble is channel. Second byte is the Controller Number, and the 3rd is the value.

Pitch Change is not a Control Change message. It's a different message type. Three bytes - 1st byte is designation and channel, and the second and third bytes are combined for a 14 bit unsigned value (8192 means no pitch bend).


Rex Coil 7 wrote:
... The sales text of the Kenton Pro CV-to-MIDI states the following (quoting) ....

"FEATURES:
*Designed to work with all types of CV inputs
*Super-fast response time
*Famous Kenton build quality
*High specification 16 bit A to D converter and reference for main CV input for rock-steady pitches
*CV/Gate/Aux inputs on 3.5mm mono jack sockets (3.5mm to 1/4" cables are available in our cables section)
*MIDI OUT socket (5 pin DIN)
*Any MIDI channel can be selected
*Switchable for V/oct & Hz/V & 1.2V/oct scaling systems
*Fine tune & scale are adjustable using front panel buttons
*Transpose (coarse tune) - up & down 12 semitones
*Adjustable pitchbend range - up to 48 semitones
*Gate mode selectable V-trig or S-trig
*Auto tune feature for easy setup"

(end quote) I highlighted the relevant information in violet. "16 bit analog to digital converters" (so plenty fine resolution for doing smooth pitch bends). And "adjustable pitchbend range" (which strongly implies their device is configured to do what I need it to do). ...


Sooo .... Kenton = 16 bit A-to-D converters ... does that become a relevant issue (in regards to converting a control voltage pitch bending device output into some type of MIDI signal that a digital synth can use for bending it's pitch)?


seriously, i just don't get it
tenembre
Rex Coil 7 wrote:
tenembre wrote:
ranix wrote:
A midi CC only has 128 possible values. I'm not sure why, it might be because some MIDI messages can go negative (127 is the max size of a signed 1-byte integer).


It's because the MSB designates it as a data or status byte, leaving 7 bits to hold the data.

ranix wrote:

Since 127 steps isn't enough resolution for pitch bend, two bytes are combined together when pitch bend messages are sent. So where a CC is usually two bytes (cc number & channel on first byte, value on second byte) the pitch bend is 3 bytes (cc number & channel on first byte, value most significant byte on next byte, value least significant byte on next byte). The two value bytes are combined to create a 16 bit signed value to use for pitch bend.


CC messages are 3 bytes, not two. 1st byte high MS Nybble designates it as a Control Change message and the LS Nybble is channel. Second byte is the Controller Number, and the 3rd is the value.

Pitch Change is not a Control Change message. It's a different message type. Three bytes - 1st byte is designation and channel, and the second and third bytes are combined for a 14 bit unsigned value (8192 means no pitch bend).


Rex Coil 7 wrote:
... The sales text of the Kenton Pro CV-to-MIDI states the following (quoting) ....

"FEATURES:
*Designed to work with all types of CV inputs
*Super-fast response time
*Famous Kenton build quality
*High specification 16 bit A to D converter and reference for main CV input for rock-steady pitches
*CV/Gate/Aux inputs on 3.5mm mono jack sockets (3.5mm to 1/4" cables are available in our cables section)
*MIDI OUT socket (5 pin DIN)
*Any MIDI channel can be selected
*Switchable for V/oct & Hz/V & 1.2V/oct scaling systems
*Fine tune & scale are adjustable using front panel buttons
*Transpose (coarse tune) - up & down 12 semitones
*Adjustable pitchbend range - up to 48 semitones
*Gate mode selectable V-trig or S-trig
*Auto tune feature for easy setup"

(end quote) I highlighted the relevant information in violet. "16 bit analog to digital converters" (so plenty fine resolution for doing smooth pitch bends). And "adjustable pitchbend range" (which strongly implies their device is configured to do what I need it to do). ...


Sooo .... Kenton = 16 bit A-to-D converters ... does that become a relevant issue (in regards to converting a control voltage pitch bending device output into some type of MIDI signal that a digital synth can use for bending it's pitch)?


seriously, i just don't get it


The final result will depends on the pitch bend resolution of what is making the sound, but 16 bits should be enough for the Kenton box to avoid adding its own issues, unless you like to set your pitch bend resolution to multiple octaves. Keep it at 1 octave or less and it should be fine.
Rex Coil 7
Just a curious little thing here. This is copied directly out of the E-MU Proteus 2000 manual (the Proteus is one of four E-MU rack synths I'm using ... all of which are from the Proteus family).

(quoting, from page #118 of the manual)

"Pitch Bend Range:

Specifies the Pitch Wheel range in semitones for the current layer. Pitch
Wheel is a standard synthesizer control which is transmitted as a MIDI
continuous controller message used (normally) to bend the pitch up and
down.
The PitchBend range is from 0 to +12 semitones or “Master.” A setting of
“0” turns the pitch wheel Off for the current layer. The Master setting uses
the Pitch Bend range defined in the Master menu."


(end quote)

Note it says "Pitch Wheel is a standard synthesizer control which is transmitted as a MIDI continuous controller message used (normally) to bend the pitch up and down." ..... MIDI continuous controller message ... as in "CC". Could this be correct?

A few things to remember before making a judgement call on this:

1.) (con) - That synth is nearly 20 years old. Maybe things were done differently then (as in the use of CC messages for pitch bend).
2.) (pro) - The manual was written in English, by people who's first language is English (so it's not a mangled translation, and the grammar is correct).
3.) (con and pro) - The statement about "CC" could be a generalization .... but then again it could just as well be a focused statement.

As I said, this is just a curious thing I found in the E-MU Proteus 2000 manual (copyright date 1998). It may be significant, it may be nothing.

seriously, i just don't get it

ONE OTHER CURIOUS BIT:


I've been doing more studying and practise on the Pyramid. There is a chance that the onboard X/Y pad may be used for pitch bend as a practical method of expression (I believe it's an option). Pitch wheels, ribbons, and joysticks can be truly mastered as pitch benders for emotive and expressive playing. Perhaps the X/Y pad on the Pyramid may be useful enough (as in refined) to make it a viable tool for convincing and practical tool for expressive pitch bending. As a fact, it's pretty much a ~ribbon~ (however the Dot Com ribbon controllers offer both position and pressure, which make them useful as expressive tools for controlling voltage ... eg; pitch with position and vibrato or filter cutoff with pressure).

Or it may be no more expressive as a hammer on a manhole cover.

lol
Rex Coil 7
NOTE: The title of this thread used to be "Squarp Pyramid CV converter to CC question (range)??". However, the discussion twisted and turned to focus more on how to go about converting control voltages to MIDI pitch bend (which was pretty much all of my own doing). That said, I've changed the title of the thread to "Voltage Controllers as MIDI pitchbend sources??" because it's far more relevant to what the overarching discussion veered off to.

End.





cookie?!?
tenembre
Rex Coil 7 wrote:


Note it says "Pitch Wheel is a standard synthesizer control which is transmitted as a MIDI continuous controller message used (normally) to bend the pitch up and down." ..... MIDI continuous controller message ... as in "CC". Could this be correct?



Technically, it's wrong, and it was wrong when they wrote it. The midi spec defined CC (continuous controller) messages and pitch bend messages as separate types of channel voice messages.

However, this technical distinction is hidden from the user. In a general sense, pitch bend is a type of controller.

Some synths let you modify pitch in some way using CC's (by assigning them to Oscillator pitch, for example), further blurring the distinction in the mind of the end user.
Rex Coil 7
tenembre wrote:
Rex Coil 7 wrote:


Note it says "Pitch Wheel is a standard synthesizer control which is transmitted as a MIDI continuous controller message used (normally) to bend the pitch up and down." ..... MIDI continuous controller message ... as in "CC". Could this be correct?



Technically, it's wrong, and it was wrong when they wrote it. The midi spec defined CC (continuous controller) messages and pitch bend messages as separate types of channel voice messages.

However, this technical distinction is hidden from the user. In a general sense, pitch bend is a type of controller.

Some synths let you modify pitch in some way using CC's (by assigning them to Oscillator pitch, for example), further blurring the distinction in the mind of the end user.


Rex Coil 7 wrote:
Just a curious little thing here. This is copied directly out of the E-MU Proteus 2000 manual .... The statement about "CC" could be a generalization ....


thumbs up
ranix
thanks for the clarification tenembre, the best response you can get when you say something wrong is a correction. Next time I'll probably remember that the leading bit is to designate data/status.

tenembre wrote:

CC messages are 3 bytes, not two. 1st byte high MS Nybble designates it as a Control Change message and the LS Nybble is channel. Second byte is the Controller Number, and the 3rd is the value.

Pitch Change is not a Control Change message. It's a different message type. Three bytes - 1st byte is designation and channel, and the second and third bytes are combined for a 14 bit unsigned value (8192 means no pitch bend).


So CC messages are:
Byte 1: 10110000
(first bit = status, next 3 bits = "I'm a CC message", next 4 bits = channel 1)
Byte 2: 00000111 (first bit = data, remaining 7 bits = CC number 7 i.e. volume)
Byte 3: 00000000 (first bit = data, remaining 7 bits = CC value)

So we see the maximum value of a CC message is clearly 127.

And Pitch Bend messages are:
Byte 1: 11100000 (first bit = status, next 3 bits = "I'm pitch bend message", next 4 bits = channel 1)
Byte 2: 00000001 (first bit = data, next 7 bits = most significant "byte" of pitch bend value)
Byte 3: 00000000 (first bit = data, next 7 bits = least significant byte of pitch bend value)

and to reassemble the value we discard the first, data, bit from each of Byte 2 and Byte 3 like so:

Byte 2: 0000001
Byte 3: 0000000

then prepend Byte 2 to Byte 3 like so:

00000010000000

which is 0b10000000, or a 1 in the 8th position, which is the number 128, and should illustrate why 2 bytes are required.

And now that I've done my homework I'll certainly remember
IR
I don't know if this adds anything to the discussion, but MIDI pitch bend does not specify a maximum (or minimum going the other way) value in terms of pitch, just a maximum pitch bend up or down. If that is a semitone, or two octaves, or something in between, is a setting of the particular synth and not a MIDI value that is used across manufacturers.
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