Using cv and synths

Alone_Alive · 2014-05-13T20:38:04.000Z

I have a oberheim SEM which I’m controlling with the A4. Unfortunately it can not track decent over 1 octave. After one octave I’m more then a semitone off.

Has anyone else experience controlling other synths with the A4? I would like to know whether mine needs to be fixed or if it’s “normal” behaviour

bluewolfse7en · 2014-05-13T21:28:55.000Z

Don’t know the SEM but Id suggest that if the pitching is wrong when triggered via midi as well as with cv, then the oscillators need calibrating.
If it’s right with midi but wrong with cv then the voltage scale will most probably be wrong.
The info you need to correct either of these scenarios should be in the SEM manual.

Alone_Alive · 2014-05-13T22:35:06.000Z

the sem only has cv in, so I can not test it with midi

bluewolfse7en · 2014-05-13T23:01:53.000Z

Really, had a quick look at a SOS review & that showed midi ports as well? Maybe a different model or something as I said I’m not familiar with it.
If it’s cv only then it’s a safe bet you OSC need calibrating.

Here you go

http://www.dendrobate-magnetique.org/synth/data/documents/documents/oberheim-sem-patchpanel-usermanual.pdf

cpaxton · 2014-05-14T00:23:41.000Z

Hey man, how’s it going. I use the a4 to trigger my moog voyager which does not track to 1 volt per octave. (it tracks at. 97 and the middle c is around 2.60 volts. The a4 is brilliant for this. What you do is change the v/octave in the cv settings to suite your synth.
So this is how I would calibrate: first you need a tuner, obviously the more accurate the better. Trigger any note in octave one. Now trigger the exact same note an octave higher. If the not is sharp you will need to decrease the voltage per octave or if it’s the other way around… You get my drift.
Honestly spend a little time with getting it perfectly, the a4’s ability to adjust it’s cv range like this is half the reason I bought one. If you are still not happy, I will buy your see off you

Alone_Alive · 2014-05-14T00:27:27.000Z

Ah I didn’t know it is possible to change the cv output range, I’ll have a look into this and get back if it worked

cpaxton · 2014-05-14T00:37:13.000Z

Yep, works a treat! The a 4 is not right in front of me now but I think you just press function + cv track you wanna change and bob’s your aunt

arise · 2014-05-14T09:24:07.000Z

I’m also sequencing my Sem Pro with my A4 via cv but I don’t have your problem.
Are you talking about the original Sem (without midi) ?

Alone_Alive · 2014-05-14T17:37:16.000Z

I have a new SEM but it’s a patchpanel, so without midi.

I went in the cv config of the A4 and set the tracking to 0.96. Now it tracks perfect over 6 octaves. Problem solved! Thanks guys.

I do wonder if a machine is bad calibrated or that the sems standard tracks at 0.96