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So, how about turning those clock outputs into an LFO? (without the
re-trigger/tune freq as close as you can method)

 

Thanks,
Simon

Canberra

AUSTRALIA

________________________________

From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf Of
Steve Maietta
Sent: Thursday, 2 March 2006 1:38 PM
To: motm@yahoogroups.com
Subject: [motm] Re: lfo synced to midi

 

Guys, Blacet sells a programmmed PIC, that with a few external
components will give you midi clock divided outputs..  check it out.

 

http://www.blacet.com/misc.html

 

~Steve

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On 3/2/06, Wheaton, Simon put forth:
>So, how about turning those clock outputs into an LFO? (without the
>re-trigger/tune freq as close as you can method)

I've given this some thought in the past.  I couldn't figure out a
way to do it using  CMOS without using a ridiculously massive amount
of chips.  However, it can be done using a microprocessor.  It could
use a counter reset by leading edges at its input to measure the
number of internal (microprocessor) clock pulses between external
(sequencer) clock pulses, then divide its maximum output by half that
number, and then increment another counter by that amount until it
reaches that maximum output, then decrement by that amount until it
reaches zero again.  Run through a DA converter this would give you a
triangle "oscillator core" that could be plugged into circuitry
similar to the MOTM-320 to give sine, square, and saw waveforms, all
with analogue shape control.

Alternatively, the square and saw could be generated directly by the
microprocessor as well using similar counter programs.  An AD
converter could be used to add PWM.  A sine output could also be
generated by the microprocessor if its programming language included
that function.

Caveat that I'm not an EE, so there might be a much better way to do
it.  However, I would be surprised to learn that there is a way that
doesn't require a microprocessor.

Not meaning to rain on anyone's parade, but syncing the frequency of an LFO
to MIDI clocks is probably only about half of the battle you're trying to
fight. The other half is syncing the phase of the LFO to measures. If you
don't have phase sync also, the LFO's phase will vary with respect to the
rest of the music every time you start/restart your sequencer. Whether or
not this is an issue depends on your needs, of course, but typically people
want phase sync when they want "tempo-synced LFOs." So part of this
hypothetical LFO would have to include parsing the other MIDI real-time
commands (in addition to clock) and acting accordingly.

Then, of course, you have to decide whether you always want your various
wave shapes to have the same phase relationship to the beginnings of
measures, and if not, how to control this relationship.

--Adam
(author of several plug-ins with tempo-synced LFOs)

I think those are reasonable expectations of synced LFO's within a
DAW or perhaps within a VA synth.  However, I do not think that is a
feature one would expect of an analogue modular.  When working with
analogue, I just assume that I have to go back to the beginning and
reset everything in order to have repeatable results.

I also think that a module that accepts an analogue clock input
rather than MIDI is more useful in the context of an analogue modular
synth.  While there are many devices that can convert MIDI clock into
analogue, MIDI clock cannot be produced or processed with the modular
itself.

Afaik, the Serge quadrature oscillator has some sort of "freeze"
function, but in general, one does not expect an LFO to be able hold
a voltage.  However, since an LFO that could sync to an incoming
clock would have to be digital, adding such a feature (such as adding
a switched jack that would only allow the LFO to run when held high)
would not be difficult.  This could also be easily implemented in a
module that accepted either MIDI or DIN sync.

Regardless, I believe that MIDI will become obsolete, but a square
wave is immortal in its simplicity.

On 3/2/06, Adam Schabtach put forth:

>Not meaning to rain on anyone's parade, but syncing the frequency of an LFO
>to MIDI clocks is probably only about half of the battle you're trying to
>fight. The other half is syncing the phase of the LFO to measures. If you
>don't have phase sync also, the LFO's phase will vary with respect to the
>rest of the music every time you start/restart your sequencer. Whether or
>not this is an issue depends on your needs, of course, but typically people
>want phase sync when they want "tempo-synced LFOs." So part of this
>hypothetical LFO would have to include parsing the other MIDI real-time
>commands (in addition to clock) and acting accordingly.
>
>Then, of course, you have to decide whether you always want your various
>wave shapes to have the same phase relationship to the beginnings of
>measures, and if not, how to control this relationship.
>
>--Adam
>(author of several plug-ins with tempo-synced LFOs)

MIDI has been obsolete for more than a decade, but is so implanted that it will probably be 
here long after we are gone. Remember MIDI2 or ZIPI? MLAN is/was also supposed to be a 
MIDI killer. What we need is a fast standardized duplex protocol for event information and 
high resolution continuous control. Home brew "ghost electronics" + MIDI are about as 
close as it gets or may ever get. I'd still like to see a USB 2.0 or (IEEE1394/Firewire) to (and 
from) CV module. But why limit to sub-sonics? Some cheap audio interfaces pass DC on 
one end and/or the other, but as Paul S. has pointed out in the past, the resolution in the 
sub-sonic range is probably inadequate for precise 1V/oct pitch control. Planetarium laser 
show controllers have used modified ADATs and sound cards to accomplish a flavor of this 
for a long time. I would think there would be some off-the-shelf industrial controller 
technology that would do the job, but in my limited searching I haven't come up with 
anything.

Barry S.

--- In motm@yahoogroups.com, Mark <yahoogroups@...> wrote: 

> 
> I think those are reasonable expectations of synced LFO's within a
> DAW or perhaps within a VA synth.  However, I do not think that is a
> feature one would expect of an analogue modular.  When working with
> analogue, I just assume that I have to go back to the beginning and
> reset everything in order to have repeatable results.
> 
> I also think that a module that accepts an analogue clock input
> rather than MIDI is more useful in the context of an analogue modular
> synth.  While there are many devices that can convert MIDI clock into
> analogue, MIDI clock cannot be produced or processed with the modular
> itself.
> 
> Afaik, the Serge quadrature oscillator has some sort of "freeze"
> function, but in general, one does not expect an LFO to be able hold
> a voltage.  However, since an LFO that could sync to an incoming
> clock would have to be digital, adding such a feature (such as adding
> a switched jack that would only allow the LFO to run when held high)
> would not be difficult.  This could also be easily implemented in a
> module that accepted either MIDI or DIN sync.
> 
> Regardless, I believe that MIDI will become obsolete, but a square
> wave is immortal in its simplicity.

I posted about this to the synth-diy list several years ago.  I also
believe I made similar comments when Synthesis Technology announced
plans to release a MIDI to CV converter.  I don't remember getting
much of a response.

I completely agree that MIDI is outdated and that we need a "fast
event information and high resolution continuous control".  However,
I do not think we need a standard so much as we need a product, and I
am surprised that with all of these companies offering analogue synth
modules that no one is offering such a product.  Nor do I have any
idea why, as I am sure it would be extremely popular.

I have read that people have used ADAT's as CV recorders by removing
filter caps on their inputs, but I have never tried that myself, and
I do not know how well it would work.  Regardless, the issue is
getting from a computer sequencer to CV.

There are two issues here, hardware and software.

I do not know about any cheap audio interfaces that can pass DC.
Perhaps they can.  Nor can I respond to what Paul S. might have said
regarding their resolution in the sub-sonic range.  As far as I can
remember, the Roland SH-101 used a 6-bit DA driving a CEM3340, and I
never had any trouble keeping mine in tune.  Also, afaik, my Kenton
Pro-4 is only 12-bit and seems to work fine.  So 16 or 24 converters
-- which are much less expensive now than they were several years ago
-- would have more than enough voltage resolution for accurate pitch
control.  Both USB and Firewire have much greater bandwidth than MIDI.

So let's say the hardware is a device that has a USB input and
several CV/gate/trigger outputs.  The software issue is that DAW's
are not designed to to generate DC voltages, so recognizing the
hardware as an audio interface would not work.  However, all DAW's
support virtual instrument plugins in AU, VST, or some other format.
So by using a plugin the DAW would simply see the hardware as just
another MIDI instrument.

Not only would the resulting CV be as accurate as a MIDI to CV
converter, and allow for much better implementation of pitch bend and
portmanteau, but the triggers and gates generated would have much
better timing than MIDI.  Imho, that alone would be worth the price
of admission.  Unlike MIDI, it could be able play several several
events exactly at the same time.

I would recommend that the specs for the hardware be publicly
available, and that the manufacturer should consider offering some
sort of SDK to encourage third-party development.  Stand-alone
applications could be developed with computer sequencing abilities
that go far beyond the limitations of MIDI.  Not only could the
hardware to generate LFO's, envelopes, clocks, and continuously
sweeping voltages, but given the ability to produce frequencies in
the audio range, it can be used as a synthesizer itself.  By adding
audio inputs to the software, it could work as envelope follower or
pitch to CV converter.

Further, the hardware would have a multitude of other uses.  Software
could be written to use it as a function generator.  People could
write applications to use it to control all sorts of things --
lighting, robotics, special effects, home theatre systems, internal
combustion engines, whatever.



On 3/3/06, coyoteous put forth:

>MIDI has been obsolete for more than a decade, but is so implanted
>that it will probably be here long after we are gone. Remember MIDI2
>or ZIPI? MLAN is/was also supposed to be a MIDI killer. What we need
>is a fast standardized duplex protocol for event information and
>high resolution continuous control. Home brew "ghost electronics" +
>MIDI are about as close as it gets or may ever get. I'd still like
>to see a USB 2.0 or (IEEE1394/Firewire) to (and
>from) CV module. But why limit to sub-sonics? Some cheap audio
>interfaces pass DC on one end and/or the other, but as Paul S. has
>pointed out in the past, the resolution in the sub-sonic range is
>probably inadequate for precise 1V/oct pitch control. Planetarium
>laser show controllers have used modified ADATs and sound cards to
>accomplish a flavor of this for a long time. I would think there
>would be some off-the-shelf industrial controller technology that
>would do the job, but in my limited searching I haven't come up with
>anything.

What he said!

Laser info, etc.:

http://www.pangolin.com/CADA-MOD.htm

I can't cite specific soundcards/audio interfaces that pass DC in or out, but I've seen their 
use touted for LFOs,etc. I have an RME ADI-2 AD/DA which is fairly high end (or medium, 
anyway - it ain't a Lavry!) which supposedly on earlier models than mine would pass DC 
both ways - not usually a good thing in audio. Even Massenburg (father of parametric EQ) 
said caps are bad, but uncompensated DC offset can be worse, isn't that why a lot of Class 
A stuff uses transformers? (Sorry, wrong group!).

Anyway, I don't think bit depth is the problem with resolution, but linearity in the DC to 20 
Hz range, since that's out of their intended operating window. So, for other than precision 
pitch control this kind of adapted hardware can work and you can create DC to 20 Hz 
program in probably any audio editor with a pencil or other waveform editing tools. 

Basic "Ghost Electronics" ala Morton Subotnick and Andre Stordeur, using a tone and VCA 
to encode and that amplitude shaped tone and an envelope follower to decode, translates 
well to digital recording and those "Ghost Tones" can be edited and synthesized in the the 
computer, all with off-the-shelf hardware and software. But matched VCA and envelope 
follower linearity is a problem for precision.

Yes, I think if you (Paul S.) make the hardware they (software developers) will come or 
you'll get stuck with a bunch of hardware!

Barry S.

--- In motm@yahoogroups.com, Mark <yahoogroups@...> wrote:

>
> 
> I posted about this to the synth-diy list several years ago.  I also
> believe I made similar comments when Synthesis Technology announced
> plans to release a MIDI to CV converter.  I don't remember getting
> much of a response.
> 
> I completely agree that MIDI is outdated and that we need a "fast
> event information and high resolution continuous control".  However,
> I do not think we need a standard so much as we need a product, and I
> am surprised that with all of these companies offering analogue synth
> modules that no one is offering such a product.  Nor do I have any
> idea why, as I am sure it would be extremely popular.
> 
> I have read that people have used ADAT's as CV recorders by removing
> filter caps on their inputs, but I have never tried that myself, and
> I do not know how well it would work.  Regardless, the issue is
> getting from a computer sequencer to CV.
> 
> There are two issues here, hardware and software.
> 
> I do not know about any cheap audio interfaces that can pass DC.
> Perhaps they can.  Nor can I respond to what Paul S. might have said
> regarding their resolution in the sub-sonic range.  As far as I can
> remember, the Roland SH-101 used a 6-bit DA driving a CEM3340, and I
> never had any trouble keeping mine in tune.  Also, afaik, my Kenton
> Pro-4 is only 12-bit and seems to work fine.  So 16 or 24 converters
> -- which are much less expensive now than they were several years ago
> -- would have more than enough voltage resolution for accurate pitch
> control.  Both USB and Firewire have much greater bandwidth than MIDI.
> 
> So let's say the hardware is a device that has a USB input and
> several CV/gate/trigger outputs.  The software issue is that DAW's
> are not designed to to generate DC voltages, so recognizing the
> hardware as an audio interface would not work.  However, all DAW's
> support virtual instrument plugins in AU, VST, or some other format.
> So by using a plugin the DAW would simply see the hardware as just
> another MIDI instrument.
> 
> Not only would the resulting CV be as accurate as a MIDI to CV
> converter, and allow for much better implementation of pitch bend and
> portmanteau, but the triggers and gates generated would have much
> better timing than MIDI.  Imho, that alone would be worth the price
> of admission.  Unlike MIDI, it could be able play several several
> events exactly at the same time.
> 
> I would recommend that the specs for the hardware be publicly
> available, and that the manufacturer should consider offering some
> sort of SDK to encourage third-party development.  Stand-alone
> applications could be developed with computer sequencing abilities
> that go far beyond the limitations of MIDI.  Not only could the
> hardware to generate LFO's, envelopes, clocks, and continuously
> sweeping voltages, but given the ability to produce frequencies in
> the audio range, it can be used as a synthesizer itself.  By adding
> audio inputs to the software, it could work as envelope follower or
> pitch to CV converter.
> 
> Further, the hardware would have a multitude of other uses.  Software
> could be written to use it as a function generator.  People could
> write applications to use it to control all sorts of things --
> lighting, robotics, special effects, home theatre systems, internal
> combustion engines, whatever.
> 
> 
> 
> On 3/3/06, coyoteous put forth:
> >MIDI has been obsolete for more than a decade, but is so implanted
> >that it will probably be here long after we are gone. Remember MIDI2
> >or ZIPI? MLAN is/was also supposed to be a MIDI killer. What we need
> >is a fast standardized duplex protocol for event information and
> >high resolution continuous control. Home brew "ghost electronics" +
> >MIDI are about as close as it gets or may ever get. I'd still like
> >to see a USB 2.0 or (IEEE1394/Firewire) to (and
> >from) CV module. But why limit to sub-sonics? Some cheap audio
> >interfaces pass DC on one end and/or the other, but as Paul S. has
> >pointed out in the past, the resolution in the sub-sonic range is
> >probably inadequate for precise 1V/oct pitch control. Planetarium
> >laser show controllers have used modified ADATs and sound cards to
> >accomplish a flavor of this for a long time. I would think there
> >would be some off-the-shelf industrial controller technology that
> >would do the job, but in my limited searching I haven't come up with
> >anything.
>

On 3/5/06, coyoteous put forth:
>Anyway, I don't think bit depth is the problem with resolution, but
>linearity in the DC to 20 Hz range, since that's out of their
>intended operating window.

That may be true for devices designed for audio, but I am quite sure
that it is possible to make a device that can convert digital data
into CV for precision pitch control, otherwise MIDI to CV converters
and MIDI synths using analogue oscillators would not be possible.  It
would likely use different converter chips, and different analogue
components (eg. 1013 op-amps as opposed to OP-275), for precision
rather than speed.

>So, for other than precision pitch control this kind of adapted
>hardware can work and you can create DC to 20 Hz program in probably
>any audio editor with a pencil or other waveform editing
>tools....Yes, I think if you (Paul S.) make the hardware they
>(software developers) will come or you'll get stuck with a bunch of
>hardware!

The point is to have precision pitch control, so both the hardware
and software must be developed.

I do not think the manufacturer should try to market the hardware
without any software at all, but rather that they should encourage
third-party software development as well.  It wouldn't be too
difficult for the manufacturer to find someone who could write a
simple VST or AU plugin.  The manufacturer wouldn't even have to get
into the software business with a need for user registration or copy
protection.  The plugins could be free downloads, as well as open
source, because they would be useless without the hardware.

Imho, as computer technology advances, and software synthesis becomes
more powerful and affordable, there is less reason to use MIDI
analogue or MIDI virtual analogue hardware synths.  There is a
growing number of computer musicians whose only hardware synths are
voltage controlled.  With USB music keyboards and controller
surfaces, MIDI interfaces are no longer necessary.  If one is using a
computer to control a CV synth such as an analogue modular, what is
the point in converting the data into MIDI first, then converting the
MIDI data into CV??  By eliminating the MIDI middleman, timing,
accuracy, and performance, are all noticeably improved.

On 3/8/06, Dale Kay (Inquisitor Betrayer) put forth:
>A standard would be needed for all the DAW software to know what was recorded.

The DAW would not need a standard to know what is recorded.  A DAW
can already record events via USB, MIDI, Ethernet from a number of
different sources, and can also generate data internally.  A
Firewire-to-CV, or USB-to-CV converter would be a playback device,
like a MIDI-to-CV converter.  All it would need is a plugin in an
existing standard such as AU or VST to show up in the DAW as a
virtual instrument.  So it would not require any sort of new industry
standard in order to work.

>Some of us record midi and audio together, midi only and audio only
>depending on the need. The USB key board and control surfaces I have
>now, use a driver to do this, such that in Sonar, I can see them,
>select them and record them. Now I can edit them as needed or alter
>then feed back into the system etc.

Well, a device that can *record* CV onto a computer is a separate issue.

However, it could also be done using plugins or drivers that allow it
so show up  as an audio or MIDI source in a DAW, just like the driver
for your USB keyboard.  However, trying to record CV as audio into a
DAW would not be practical and could cause problems with the host,
and using software to convert the data into MIDI would result in a
significant loss of information.

Imho, recording and editing CV information to its full advantage
would require a stand-alone application.  For example, Numerology is
an excellent stand-alone sequencer application for OSX.  While it can be
synchronized and exchange data with a DAW, it works on its own like a
virtual hardware sequencer with different modules than can create
clocks, lfo's, gates, pitches, etc. than can be patched together in
different ways and used to record tracks without using MIDI.

>All for it if the big boys will make a standard.

All it takes is one company willing to make a product.  No standard is needed.

> All it takes is one company willing to make a product.  No 
> standard is needed.

And for that you need a convincing market case, which may be the biggest
stumbling block. The modular-synthesizer-using market is not a huge one.
Subtract from that all of its users who are perfectly happy with MIDI-CV
converters and you're left with a fairly small number of prospective buyers.
Paul could certainly do the hardware engineering for such a device, and I
(or rather Audio Damage) could certainly do the AU/VST plug-in, but it's not
clear to me that we'd collectively sell enough of the package to even make
back the R&D costs. I'm basing that on my company's sales volumes for
plug-ins of much, much wider interest and some wild-ass guesses about Paul's
volumes. Just my $0.02 worth, of course.

--Adam

I don't think that the modular synth market -- with at least a dozen
manufacturers -- is that small.  Nor do I think that any of those
manufacturers could have made a convincing business plan if they
wanted to borrow the money to start their companies.  It took courage
and vision.

Yet, ignoring that this device could be used with any instrument that
accepts triggers or control voltages, within the modular synth market
people often pay several hundred dollars for modules with little or
no musical utility.  This device would offer three huge advantages:

1) It's superior timing and and ability to generate continuous
voltages to control pitch makes it far more accurate and musicality
expressive -- in the traditional sense -- than a MIDI-to-CV
converter.

2)  With the right software, it could do a number of practical things
such as MIDI-synced LFO's or pitch-to-CV (that could properly track a
bass or slide guitar) that are currently impossible with anything on
the market.

3) With the right software, it could replace the use of modules such
as lag processors, envelope generators, LFO's, etc.  For example,
instead of generating the trigger and gate to control analogue
envelope generator, it could generate the envelope directly, but with
response to velocity or other data within the DAW.

Based on the private email I've received, people either think it's a
great idea or they don't seem to understand how this device would
work.

On 3/9/06, Adam Schabtach put forth:

>  > All it takes is one company willing to make a product.  No
>  > standard is needed.
>
>And for that you need a convincing market case, which may be the biggest
>stumbling block. The modular-synthesizer-using market is not a huge one.
>Subtract from that all of its users who are perfectly happy with MIDI-CV
>converters and you're left with a fairly small number of prospective buyers.
>Paul could certainly do the hardware engineering for such a device, and I
>(or rather Audio Damage) could certainly do the AU/VST plug-in, but it's not
>clear to me that we'd collectively sell enough of the package to even make
>back the R&D costs. I'm basing that on my company's sales volumes for
>plug-ins of much, much wider interest and some wild-ass guesses about Paul's
>volumes. Just my $0.02 worth, of course.

A really good place to discuss this is the new ComputerVoltageSources
group here on Yahoo.  Lotsa cool stuff going on there...

Mike

--- In motm@yahoogroups.com, Mark <yahoogroups@...> wrote:
>
> 
> I don't think that the modular synth market -- with at least a dozen
> manufacturers -- is that small.  Nor do I think that any of those
> manufacturers could have made a convincing business plan if they
> wanted to borrow the money to start their companies.  It took courage
> and vision.
> 
> Yet, ignoring that this device could be used with any instrument that
> accepts triggers or control voltages, within the modular synth market
> people often pay several hundred dollars for modules with little or
> no musical utility.  This device would offer three huge advantages:
> 
> 1) It's superior timing and and ability to generate continuous
> voltages to control pitch makes it far more accurate and musicality
> expressive -- in the traditional sense -- than a MIDI-to-CV
> converter.
> 
> 2)  With the right software, it could do a number of practical things
> such as MIDI-synced LFO's or pitch-to-CV (that could properly track a
> bass or slide guitar) that are currently impossible with anything on
> the market.
> 
> 3) With the right software, it could replace the use of modules such
> as lag processors, envelope generators, LFO's, etc.  For example,
> instead of generating the trigger and gate to control analogue
> envelope generator, it could generate the envelope directly, but with
> response to velocity or other data within the DAW.
> 
> Based on the private email I've received, people either think it's a
> great idea or they don't seem to understand how this device would
> work.
> 
> On 3/9/06, Adam Schabtach put forth:
> >  > All it takes is one company willing to make a product.  No
> >  > standard is needed.
> >
> >And for that you need a convincing market case, which may be the
biggest
> >stumbling block. The modular-synthesizer-using market is not a huge
one.
> >Subtract from that all of its users who are perfectly happy with
MIDI-CV
> >converters and you're left with a fairly small number of
prospective buyers.
> >Paul could certainly do the hardware engineering for such a device,
and I
> >(or rather Audio Damage) could certainly do the AU/VST plug-in, but
it's not
> >clear to me that we'd collectively sell enough of the package to
even make
> >back the R&D costs. I'm basing that on my company's sales volumes for
> >plug-ins of much, much wider interest and some wild-ass guesses
about Paul's
> >volumes. Just my $0.02 worth, of course.
>