Sending Pitch to Analogue Osc

Jul 13, 2008 at 10:57pm

Sending Pitch to Analogue Osc

Hello.

Is there a way for me to send pitch information to an analogue oscillator without having to use MIDI pitch or 0-127 steps.

I use the Kenton Pro Solo for MIDI/CV conversion and I have made a sequencer in MAX but I don’t like using quantized pitches. I have a quantizer in my modular so if I want I can use that. I thought of sending Pitch Bend but it only has a range of 12 semitones on the Kenton Pro Solo.

thanks

Ken

#38870
Jul 14, 2008 at 11:09am

perhaps you should try sending CV directly by using an audio card with DC coupled audio outs (eg. motu 828 mk2)…

hth,

j

#135984
Jul 14, 2008 at 3:49pm

OK thanks I have the MOTU ultralite so I could try that. I’ll hook it up to an oscilloscope and see if it sends DC coupled.

Has nobody on the list sent raw pitch information to a modular synth or does everybody use MIDI?

#135985
Jul 14, 2008 at 5:37pm

depends what you mean by raw pitch info… if it’s CV, it’s going to be dependent on the pitch voltage standard.

j

#135986
Jul 14, 2008 at 7:23pm

Grizzle schrieb:
> Has nobody on the list sent raw pitch information to a modular synth
> or does everybody use MIDI?

Midi is quantized by design, you definitely need a DA converter…

Stefan


Stefan Tiedje————x——-
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#135987
Jul 14, 2008 at 9:41pm

OK Justin… I understand now. Just take the Kenton Pro Solo out of the loop and go straight from the outs on my soundcard…. well that would be just great. I have 8 outs on the MOTU so essentially that could be 8 CV sends…

Ok… I’ll try that and come back.

#135988
Jul 14, 2008 at 9:43pm

On Jul 14, 2008, at 12:23 PM, Stefan Tiedje wrote:
> Midi is quantized by design, you definitely need a DA converter…

Which is also quantized to it’s resolution.

MIDI notes + pitchbend can achieve pretty high resolution; seven bit
resolution for the note, and 14 bit resolution from bend. If bend is
set to one semitone, and is sent as 14 bit bend information, pretty
high resolution can be had.

MIDI’s temporal resolution, on the other hand, can be somewhat lacking.

Chris Muir
cbm@well.com

http://www.xfade.com

#135989
Jul 15, 2008 at 11:44am

Quote: Grizzle wrote on Mon, 14 July 2008 22:41
—————————————————-
> OK Justin… I understand now. Just take the Kenton Pro Solo out of the loop and go straight from the outs on my soundcard…. well that would be just great. I have 8 outs on the MOTU so essentially that could be 8 CV sends…
>
> Ok… I’ll try that and come back.
—————————————————-

that’s exactly what i mean! only problem is that analog circuits are built to different voltage standards… so you need to bear that in mind, cos the voltage output of the sound card might not match up to the analog electronics. this could lead to hardware damage, so proceed carefully!

it’s also worth bearing in mind that most CV inputs use electronics to smooth out the input signals (slew rate), so sending a rect~ @ 800hz might not provide the FM sound you were after… YMMV depending on the synth manufacturer.

hth,

j

#135990
Jul 15, 2008 at 12:05pm

i would be careful if I were you, MOTU have advised people against it.

See here http://www.nononancy.com/cvcontrol/index.html

I would like to see a USB OSC to CV convertor for controlling analog synths with high resolution. Or an audio interface designed for this purpose. Anyone aware of such a thing?

oli

#135991
Jul 15, 2008 at 12:48pm

I always have to put my support in every time I see one of these threads. A USB to CV converter would be brilliant and end my quest for an alternative to MIDI/CV once and for all. Even better would be a way to treat sampled CV as an audio file, i.e., CV to USB, and manipulate it as such.

#135992
Jul 15, 2008 at 1:18pm

yes, i agree…a properly designed USB < -> CV would be really good, and no doubt safer than [ab]using a motu 828.

;)

j

#135993
Jul 15, 2008 at 3:27pm

justin skrev:
> yes, i agree…a properly designed USB < -> CV would be really good, and no doubt safer than [ab]using a motu 828.
>
What would be the specs people are looking for in max->cv kit?
0-5v digital is a given, for triggers.

But what about control voltages?
-2.5v -> +2.5v or 0v -> +8v? Even wider range?
+-5v, like the VCOs of a doepfer system?

And what about resolution? would 10bit suffice?

^^^^ I think the above shows why we aren’t seeing a lot of these
products, perhaps?

Andreas.

#135994
Jul 15, 2008 at 3:42pm

Quote: Wetterberg wrote on Tue, 15 July 2008 09:27
—————————————————-
> What would be the specs people are looking for in max->cv kit?
> 0-5v digital is a given, for triggers.
>
> But what about control voltages?
> -2.5v -> +2.5v or 0v -> +8v? Even wider range?
> +-5v, like the VCOs of a doepfer system?

Given that old Moog & Buchla systems were 1v/octave for the oscillators (if I’m not mistaken – it’s been a while) it would be nice to have a 10 octave range, i.e. 0-10v.

On the other hand, some sort of switchable range (hardware or software) would make it more flexible.

>
> And what about resolution? would 10bit suffice?

I’d rather see at least a 16 bit resolution for pitch and amplitude signals.

#135995
Jul 15, 2008 at 3:49pm

Yes, 16 bit, at least.
1v/Oct standard

#135996
Jul 15, 2008 at 4:15pm

Quote: Wetterberg wrote on Tue, 15 July 2008 16:27
—————————————————-
> ^^^^ I think the above shows why we aren’t seeing a lot of these
> products, perhaps?
>
> Andreas.
—————————————————-

very true…

perhaps one can make a system which could switch between the most common voltage ranges (doepfer / moog / korg).

16 bit would be nice, and a decent number of outlets (>=8). i have found that midi 2 cv kits are a bit limiting in terms of outlets, admittedly i only bought the cheapo doepfer box…

j

#135997
Jul 15, 2008 at 4:44pm

On Jul 15, 2008, at 8:27 AM, Andreas Wetterberg wrote:

> What would be the specs people are looking for in max->cv kit?
> 0-5v digital is a given, for triggers.

There are many devices which need a 10v gate/trigger. The analog synth
world has had many schemes for gating/triggering. There really isn’t
much of a standard.

> But what about control voltages?
> -2.5v -> +2.5v or 0v -> +8v? Even wider range?
> +-5v, like the VCOs of a doepfer system?

I would like to see 0-10v, but I can imagine needing up to -10v to10v
for some systems.

> And what about resolution? would 10bit suffice?

For pitch, I don’t think 10 bit resolution is enough.

> ^^^^ I think the above shows why we aren’t seeing a lot of these
> products, perhaps?

Agreed, and we haven’t even gotten into the question of temporal
resolution.

-C

Chris Muir
cbm@well.com

http://www.xfade.com

#135998
Jul 15, 2008 at 5:05pm

Andreas Wetterberg schrieb:
> But what about control voltages?
> -2.5v -> +2.5v or 0v -> +8v? Even wider range?
> +-5v, like the VCOs of a doepfer system?

The standard is 1V/Octave, originally introduced by Moog…
Except for Korg, most synths do that.

> And what about resolution? would 10bit suffice?

Certainly not, especially for pitch, even Midi uses 14-bit…

Stability will also be an issue…

Stefan


Stefan Tiedje————x——-
–_____———–|————–
–(_|_ —-|—–|—–()——-
– _|_)—-|—–()————–
———-()——–www.ccmix.com

#135999
Jul 15, 2008 at 5:32pm

Chris Muir skrev:
> On Jul 15, 2008, at 8:27 AM, Andreas Wetterberg wrote:
>> What would be the specs people are looking for in max->cv kit?
>> 0-5v digital is a given, for triggers.
> There are many devices which need a 10v gate/trigger. The analog synth
> world has had many schemes for gating/triggering. There really isn’t
> much of a standard.
You’re right Chris. And I really value your opinion on this – thanks.
>> But what about control voltages?
>> -2.5v -> +2.5v or 0v -> +8v? Even wider range?
>> +-5v, like the VCOs of a doepfer system?
> I would like to see 0-10v, but I can imagine needing up to -10v to10v
> for some systems.
And then we’re in the realm of a do-it-all unit. Those are usually for
labs ;)
>> And what about resolution? would 10bit suffice?
> For pitch, I don’t think 10 bit resolution is enough.
Me neither, at this point. 12bit is low, too, even, but might be “enough”.
>> ^^^^ I think the above shows why we aren’t seeing a lot of these
>> products, perhaps?
> Agreed, and we haven’t even gotten into the question of temporal
> resolution.
Thanks again for your insights, Chris. Temporal resolution is important
if we want DCOs directly from the computer, doing FM and the like.
Again, the do-it-all.

The “do-it-all” unit is essentially a multi-out dc-coupled hi voltage
audio interface. That would be quite expensive to develop, and doing so
would also be quite redundant.

One approach would be a bank of envelope followers with a gain stage –
just hook up your regular audio interface and start following ;)
The downside to that would be a certain amount of slew, but in most
applications it would work well – envelopes, lfos, pitch. Thoughts?

Andreas.

#136000
Jul 15, 2008 at 5:55pm

Stefan Tiedje skrev:
> Andreas Wetterberg schrieb:
>> But what about control voltages?
>> -2.5v -> +2.5v or 0v -> +8v? Even wider range?
>> +-5v, like the VCOs of a doepfer system?
> The standard is 1V/Octave, originally introduced by Moog…
> Except for Korg, most synths do that.
yes, but that speaks to the resolution. In the above I am talking about
range, ie absolute voltages.
>> And what about resolution? would 10bit suffice?
> Certainly not, especially for pitch, even Midi uses 14-bit…
To be fair plain midi is 7-bit. The problem is that it doesn’t seem to
be a unit that people will accept doesn’t go whole hog on everything –
it has to be able to do and withstand everything you throw at it.

I’ll ask my engineer colleagues whether a 16-output 16bit unit can be
built within reason.

I’m afraid I already know the answer there…

Andreas

#136001
Jul 16, 2008 at 2:33am

On Jul 15, 2008, at 8:42 AM, smill wrote:
> Given that old Moog & Buchla systems were 1v/octave for the
> oscillators (if I’m not mistaken – it’s been a while) it would be
> nice to have a 10 octave range, i.e. 0-10v.

Buchla has never been 1v. / octave. Buchla is .1v / semitone, or 1.2v
per octave.

A simple scaling operation, though.

-C

Chris Muir
cbm@well.com

http://www.xfade.com

#136002
Jul 16, 2008 at 2:36am

Ahh yes, it has been a while indeed…

Quote: Chris Muir wrote on Tue, 15 July 2008 20:33
—————————————————-
>
> On Jul 15, 2008, at 8:42 AM, smill wrote:
> > Given that old Moog & Buchla systems were 1v/octave for the
> > oscillators (if I’m not mistaken – it’s been a while) it would be
> > nice to have a 10 octave range, i.e. 0-10v.
>
>
> Buchla has never been 1v. / octave. Buchla is .1v / semitone, or 1.2v
> per octave.
>
> A simple scaling operation, though.
>
> -C
>
> Chris Muir
> cbm@well.com
> http://www.xfade.com
>
>
>
>
>
>
>
—————————————————-

#136003
Jul 31, 2008 at 11:15pm

Quote: oli larkin wrote on Tue, 15 July 2008 08:05
—————————————————-
> i would be careful if I were you, MOTU have advised people against it.
>
> See here http://www.nononancy.com/cvcontrol/index.html

—————————————————-

Anyone got a guess why MOTU says there will be a problem outputting DC voltages? Is that act alone enough to damage the unite or are they assuming high risk due to interfacing the 828 with other hardware combined with possibly faulty electronics?

#136004
Aug 1, 2008 at 2:05pm

Thought ye might be interested in this clip.

http://jp.youtube.com/watch?v=Y-6sv-u3fDw

It’s a clip of a Plan B modular being controlled by MAX through the 828 MKII. It seems to work pretty well. No sign of his 828MKII blowing up…

The poster give a fairly good description as well.

#136005
Aug 1, 2008 at 6:14pm

Roth Michaels schrieb:
> Anyone got a guess why MOTU says there will be a problem outputting
> DC voltages? Is that act alone enough to damage the unite or are
> they assuming high risk due to interfacing the 828 with other
> hardware combined with possibly faulty electronics?

I guess it is because there will be a limit for the current. If you
create a short circuit, it might (or will?) blow up the dac…
If your cv inputs have reasonable high impedance I don’t see any problem…

Stefan


Stefan Tiedje————x——-
–_____———–|————–
–(_|_ —-|—–|—–()——-
– _|_)—-|—–()————–
———-()——–www.ccmix.com

#136006
Oct 8, 2010 at 2:21pm

i actually think they say that because they released Volta and dont want poeple to buy it.. an opinion only.

#136007
Aug 10, 2013 at 8:03am

Could we focus on Eurorack and usb?

#258520
Aug 10, 2013 at 3:36pm

motu ultralite hybrid.

#258548

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