Kill an LFO When Stopping Track

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Goodbye
Posts: 220
Joined: 21 May 2017

01 Dec 2017

I'm working on some music driven by Lectric Pand's PSQ-1684. If you don't know the RE, at its basic level it is a pulse generator that can drive instruments rhythmically. By default it is synced to the transport, meaning when you press play on the track it starts and when you press stop, it stops.

However alongside it I am using a load of LFOs to drive other elements, and the problem is that they don't stop when I hit stop. They keep pulsing away. Is there a way to mute / unmute a cv signal when the track is playing / stopped? Little LFO has an on / off switch for each LFO which I could toggle using a combinator, but there is no play / stop signal to use as a trigger.

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selig
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Location: The NorthWoods, CT, USA

01 Dec 2017

You can try a crude approach for creating a “transport playing” signal. Use a sine wave on an audio track to side-change ‘gate’ the signal you want to stop. When the transport stops, the sine stops, the gate closes, the LFO signal is muted.

Don’t know 100% how this would be setup, just making a suggestion for a starting point if nothing else works for you.


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Goodbye
Posts: 220
Joined: 21 May 2017

01 Dec 2017

Interesting idea. Thanks.

madmacman
Posts: 786
Joined: 18 Jan 2015

01 Dec 2017

I had a crude idea, using a Thor and the Volt CB-1 RE. See attached combinator

Short (attempt of) explanation:

1. I set the Thor sequencer to length = 1 step
2. in the matrix I use the "Seq. end" trigger as gate for the global envelope
WHY? The envelope adds sort of "inertia" to the trigger to keep it constantly "high"
3. I route the Global env to CV1 out
4. I feed the CB-1 with the env signal from Thor CV1
5. CB-1 mode set to "Compare"
6. switch 0 / 127 taken from CB-1 output.

Result: When I hit Play on Reason, I get a constant high trigger pulse. Envelope Release ensures the trigger doesn't fall to "Low" too fast until next High impulse

When I stop Play, then the CB-1 output goes Low relatively fast.

Maybe not a perfect solution, but a starting point without extra audio lane.
Run_Checker.cmb.zip
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Last edited by madmacman on 01 Dec 2017, edited 1 time in total.

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AttenuationHz
Posts: 2048
Joined: 20 Mar 2015
Location: Back of the Rack-1

01 Dec 2017

Thing about LFO's: when they are on they are playing when they are stopped they are off! I often use Pulsars 2nd LFO because it has an on/off but if I want more control with fewer Devices I use LittleLFO(free) When you turn an LFO off you are essentially stopping it.

Another option you should consider is the Envelopes on Europa. They are just custom LFO's and the easy part of this is Key Trig once enabled the Env/LFO in this case will reset to the start upon getting a midi signal on the sequencer or gate on. I requested that the envelopes be slower on Europa and Grain in beta but it didn't happen. An 8 bar LFO is the lowest it will go down to. Also with Loop off on Europa's Envelope it is essentially a one shot LFO you start the envelope again through gate or midi note on.

Grain uses the same envelopes but you have to have a sample loaded to access the envelopes.


With using Europa I'm not sure if it is possible to stop the LFO when the track is stopped but with Key Trig all you need to do is mute the LFO with Pongasoft A/B or similar then when you want everything to sink use a midi clip to reset the envelope.

I'll have another think on how to do that automatically!

Right: What you would have to do is add a track for Europa and RPG-8 in the attached combi add a note that loops around 1 bar and repeat it for the length required. When the gate is detected (sequencer playing) by RPG it switches the A/B on when the gate is received by Europa it resets the LFO/Envelope. When the sequencer is playing the LFO is unmuted. When you press stop the note is off on RPG-8 and switches the A/B to no signal for the LFO essentially muting it. Pea's in a pod! :D

The RE's in the combi are free. I assumed you are on 10.
If you get an error for the combi patch rename the patch to "PiP.cmb" or whatever you like just include the .cmb extension. Rmember to add the notes to the sequencer for RPG and Europa. Hope this is of some help.
Reset LFO Turn Off when Stopped.zip
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emilng
Posts: 99
Joined: 03 Oct 2017

01 Dec 2017

I ran into the same issue and the way I dealt with it was to have Little LFO wrapped in a combinator and one of the pulse generators in PSQ-1684 generating a constant pulse when it's running. You can do this by setting division to 1 and set width to 100. I take the output for that pulse, and connect to rotary 1 for the combinator. In the programmer for the combinator I have rotary 1 controlling LFO 1 active, LFO 2 active, etc... Make sure the rotary is set to 0 so it's not keeping the LFOs on when there's no signal.

Goodbye
Posts: 220
Joined: 21 May 2017

05 Dec 2017

Thanks everyone.

Some good suggestions there.

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