Problem triggering soundlab with midi -> cv circuit

Lemmy

I would like to switch off my midi input using my CV in switching jacks somehow, so that it's either CV in or midi in.

I could just break the midi in when a jack is inserted. See wire A in pic. I think that would work with a jack in CV 1 in, but not 2. (My midi in triggers both oscs.) I suppose I could run the other midi in wire, wire B, via the switch and tip connectors of osc 2.

Look like it would work?

switching.jpg

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Zodiak

Lemmy I can see what you mean and I it is possible, but I don't think that your idea here will work as it is. Crying or Very sad

MIDI signals circuits are a bit special and designed to eliminate mains hum so you can't really go around switching them like that.

A more hygienic way would be to leave your MIDI > CV as it is and then feed the C/V output from it through the jack sockets. That would work.

I have drawn a picture and will try to attach it later.
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Lemmy · Posted: Mon Jan 21, 2008 6:58 am Post subject:

Hi Zodiak,
I had a hunch it wasn't quite right. I also thought about using the jacks to switch some part of the midi->cv circuit, instead of the midi input signal.

Your idea sounds better though. Look forward to seeing the pic.
Thanks!

Zodiak · Posted: Mon Jan 21, 2008 10:41 am Post subject:

Mine looks a bit like this

Posted Image, might have been reduced in size. Click Image to view fullscreen.

What this means is that I can play it from my MIDI keyboard but if I plugged in a CV keyboard it would take precedence.

There is however one slight restriction, in that you easily control one VCO and the AR from the MIDI keyboard and play one note and you can play the other VCO with a CV keyboard but you can't feed another trigger signal in as that would cut out the MIDI.

Luckily there is only one AR so its not an issue Smile

Its also not an issue for me as I don't have a CV keyboard anyway Smile

Lemmy · Posted: Mon Jan 21, 2008 2:05 pm Post subject:

That seems like a really nice solution.

Only one thing which might be an issue. I don't have a CV keyboard either but it's possible that I'll build a sequencer sometime. It would be nice to have both oscillators triggered by one CV in. That's why I have a wire from the tip of my Osc 1 CV in going to the switch pin of Osc 2 CV in. I'm not sure if that would be a problem using your layout? Possibly not.

It's not such a big deal actually, as I guess I could just use a Y cable to two jacks if I only have one CV source but want to trigger both oscillators.

I guess I will use your elegant method and try a test with osc 1 cv in triggering osc 2 cv in.

Zodiak · Posted: Mon Jan 21, 2008 3:25 pm Post subject:

OK then how about this?

Posted Image, might have been reduced in size. Click Image to view fullscreen.

If you only use the MIDI then both VCOs will track that.

If you put a jack into X1 then VCO1 will follow the CV on the jack and VCO2 will follow the MIDI

If you put a jack into X2 then both VCOs will track the same CV

If you put a jack in both then each VCO will have its own feed and both will ignore the MIDI. Laughing

Lemmy · Posted: Tue Jan 22, 2008 6:42 am Post subject:

Looks good! Thanks.
OK, now I can finally label up my back panel and put everything together...