Sending CV from Doepfer MAQ16/3 to custom made analog synths

[omereilam]

Hello,

I have access to many custom made analog synths (housed in The Institute of Sonology) and I would like to be able to communicate with them by sending MIDI note data from my computer.

I also found a Doepfer MAQ16/3 sequencer that I could potentially use for this purpose, i.e. by sending MIDI data to this module and there convert it to CV.

To begin with I was trying to hook up the Doepfer to the patch bay, start the sequencer, and use the first CV output to control the pitch of one of the oscillators in the studio. At the beginning I thought it worked but then I realised that the pitch range is very narrow (around 1 octave) and not full range.

I checked and found that both the Doepfer and the oscillator work in the range of 0 to 5V and probably both maintain the 1V per octave standard.

I think that perhaps I was not outputing the full voltage range from the Doepfer. I tried playing around with the presets but it didn't really make too much of a difference.

I was hoping someone here might have some ideas on how to make it work.

Thanks much!
omer

[whyterabbyt]

I also found a Doepfer MAQ16/3 sequencer that I could potentially use for this purpose, i.e. by sending MIDI data to this module and there convert it to CV.

Am I right in thinking that what you're trying to do is use the 'transpose' capability and a one note-sequence to make it behave like a MIDI-CV convertor? Im not entirely convinced how well, that'll work, but anyway...

The manual can be found here;

http://www.doepfer.de/maq_m_e.htm

Ive not tried this, and I personally think a proper MIDI-CV convertor is going to be a better solution, but here's what I think might be relevant:

If you look under section '2.2.3.1. EVENT' you'll see that its almost certainly 'relative' mode you want (transposition based on MIDI input), and to get more than one octave of transposition, you need to change the range, between one and 5 octaves (ie 1-5V over CV)

nr1... NOTE ON/OFF relative
to
nr5

More explanation of the modes, from the manual:

If "Absolute" is selected, then the note is entered directly with the dial and will not be altered by incoming note-instructions. In this case the note-values start at MIDI-Code 36 (= the low C on a 5-octave keyboard). In "relative" NOTE ON-instructions entering via MIDI-IN are used for transposition of the sequence, i.e. the note-values entered with the dials are added to those coming from MIDI-IN. In order to be able to implement the TRANSPOSE-function, the MIDI-channel of the incoming note-instructions must be the same as that of the row.

There are 5 different scales ranging from 1 to 5 octaves for both all operating modes. For example, with nA1 the range of notes for a full turn of a dial is 1 octave, with nA5 it is 5 octaves. For the corresponding CV output this means a voltage difference of 1V (nA1) ... 5V (nA5). The reference note for lowest CV (about 0.25V) is the note with MIDI code 36 (C).

[omereilam]

Am I right in thinking that what you're trying to do is use the 'transpose' capability and a one note-sequence to make it behave like a MIDI-CV convertor?

Yes, I think that sounds about right.
The issue I was having is more basic however.

Like I was trying to explain at first I just tried to use the sequencer to output CV without any MIDI sent to it, i.e. just by using the row dials. I did switch to the Absolute 5 octave preset and connected the output of CV1 to the pitch input of an oscillator. Then I turned some of the dials to the minimum value and others to the maximum, but the result was a range much lower than 5 octaves.

[whyterabbyt]

Am I right in thinking that what you're trying to do is use the 'transpose' capability and a one note-sequence to make it behave like a MIDI-CV convertor?

Yes, I think that sounds about right.
The issue I was having is more basic however.

Like I was trying to explain at first I just tried to use the sequencer to output CV without any MIDI sent to it

Ah, sorry, I didnt pick up on that bit.

, i.e. just by using the row dials. I did switch to the Absolute 5 octave preset and connected the output of CV1 to the pitch input of an oscillator. Then I turned some of the dials to the minimum value and others to the maximum, but the result was a range much lower than 5 octaves.

Hmmm. That could either means that something ( the MAQ , the module, or both) isnt tracking properly (ie not doing 1 octave per volt).
First thing I'd do is check the MAQ output with a voltmeter, and ensure its doing 1,2,3,4,5V properly. Then I'd try and work out what the frequency response per octave behaviour actually is (ie try and get a sense whether its linear or logarithmic and how it is tracking).
If its properly logarithmic but the tracking is off', then I'd see if I can find some trim pots for CV response on the board.
However, being custom modules, its entirely possible they dont/cant do 1V/octave.

One way to control them if that's the case might be to look at something like the Expert Sleepers Silent Way software and a suitable audiocard or interface. The SW software should be able to calibrate itself for all sorts of CV responses.

[omereilam]

I just tried your suggestion and connected the first CV output of the MAQ to an oscilloscope.
I put the MAQ on the absolute 5 octaves preset and then used the SINGLE STEP mode to stay on one column and adjust the voltage of the first row dial.
When I looked at the oscilloscope the voltage stayed on zero no matter the position of the dial. It seemed like whenever I moved the dial there was a very brief jump in voltage which then returned quickly to zero.

Am I missing something here or could it be that the MAQ is dysfunctional?

Thanks again!
omer