Grandmother - Eurorack oscillator

Mother-32, DFAM, Subharmonicon, Grandmother, Matriarch
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jonas
Posts: 3
Joined: Sun Dec 01, 2019 11:47 am

Grandmother - Eurorack oscillator

Post by jonas » Sun Dec 01, 2019 12:07 pm

Hello!

Firstposter here :)

I have a small issue which i can't find a solution for (so far..).

I've got an Grandmother and i accidentally bought a eurorack..... :wink: (Roland 500 system).

My problem is that I want to play the roland oscillator with the keyboard from the Grandmother. (The Roland oscillator is always running btw).

I connect the keyboard out from the Grandmother to the key/pitch in on the roland system (i know its the correct input). When i press a note on the keyboard the Roland oscillator plays that key.

BUT. If i don't press any key on the Grandmother i can hear the roland oscillator running (in one tune). If i press and then release the keyboard, the note i press will play but when i release it the roland oscillator is still running.

I'm quite new to this and from my point of view it seems like the Grandmother fails to tell the roland oscillator to shut up when a key is not pressed on the keyboard.

I don´t want to completely shut all of the other modules off on the grandmother because i want to be able to connect filters and the moog oscillators etc etc too.

I´m quite sure that I'm missing some small detail here. I'm also sure that it has to do with the grandmother settings.

I´m sending my hope out to you folks so that I´ll hopefully will retain my night sleep and start focusing on getting deeper down the module addiction ;)

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_DemonDan_
Posts: 1265
Joined: Mon Nov 16, 2009 4:52 pm

Re: Grandmother - Eurorack oscillator

Post by _DemonDan_ » Mon Dec 02, 2019 10:11 am

jonas wrote: Sun Dec 01, 2019 12:07 pmI want to play the Roland oscillator with the keyboard from the Grandmother. (The Roland oscillator is always running btw).

I connect the keyboard out from the Grandmother to the key/pitch in on the Roland system (i know its the correct input). When i press a note on the keyboard the Roland oscillator plays that key.

BUT. If i don't press any key on the Grandmother i can hear the Roland oscillator running (in one tune). If i press and then release the keyboard, the note i press will play but when i release it the Roland oscillator is still running.

I'm quite new to this and from my point of view it seems like the Grandmother fails to tell the Roland oscillator to shut up when a key is not pressed on the keyboard.
Hi jonas,

Welcome to the world of analog synthesis, where the oscillators are always on.
(It's one of the many things we love about analog synths.)

The sound from analog oscillators are stopped by a VCA (voltage controller amplifier) farther down the audio path.

To get the oscillators and filters to "shut up", you need to take the output of the oscillator (or oscillators going through a mixer, then through a filter) and send the audio to a VCA. It's the VCA (usually controlled by an Envelope from the Grandmother or Roland System) that then shuts everything up.

Hope that helps.
_ :twisted: _DemonDan_ :twisted: _

jonas
Posts: 3
Joined: Sun Dec 01, 2019 11:47 am

Re: Grandmother - Eurorack oscillator

Post by jonas » Tue Dec 03, 2019 6:06 pm

Hi _DemonDan_

Big thanks for your reply.

if i go kb-out from GM to Eurorack oscillator (and the through filter and VCA in the eurorack) and then output the VCA in to the GM VCA it stops playing when i release the keyboard. (it also work if i put oscillator from eurorack straight to VCA on the GM.

so far so good :)

but if i want to use the signal chain above with the exception that i want to output from eurorack VCA to eurorack output module, the sound from the oscillator won't stop.

I also tried to use the envelope in my eurorack, but with no success.

Mabye it´s not a Grandmother question anymore but it´s a bit annoying and i totally feel that I'm missing one small detail...

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_DemonDan_
Posts: 1265
Joined: Mon Nov 16, 2009 4:52 pm

Re: Grandmother - Eurorack oscillator

Post by _DemonDan_ » Wed Dec 04, 2019 1:31 pm

jonas wrote: Tue Dec 03, 2019 6:06 pm...I want to use the signal chain above with the exception that i want to output from eurorack VCA to eurorack output module, but the sound from the oscillator won't stop.

I also tried to use the envelope in my eurorack, but with no success.

Mabye it´s not a Grandmother question anymore but it´s a bit annoying and i totally feel that I'm missing one small detail...
Universally, VCAs need to be set to silence, with ONLY the control output of an Envelope pushing them open. If the VCA is not set to be silent, it won't be silent.
_ :twisted: _DemonDan_ :twisted: _

jonas
Posts: 3
Joined: Sun Dec 01, 2019 11:47 am

Re: Grandmother - Eurorack oscillator

Post by jonas » Fri Dec 06, 2019 12:27 pm

Well well. It worked out just fine (finally!!!)

Many many thank`s to you _DemonDan_!

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