Metropolix: How to play a silent rest?

Eurorack
#1

I’ve tried adjusting gate length, setting stages to REST, the result in all cases is ‘rested’ notes are held over - quite the opposite of the musical expression, to rest.

#2

During the unwanted note hold, is your LED lit above the GATE out jack in question? Assuming the GATE out LED stays lit when you want it unlit, several things could be at play.

Silent rests based on unlit gate LED can be produced (most simply but not only) like this, (if no other custom tweaks are intervening):

  • Set the Track’s Gate Type option to “Switch”, and have the Stage’s GATE TYPE switch in the bottom setting (unfilled rectangle) on the physical panel. Send GATE out to VCA.

OR

  • Set the Track’s Gate Type option to “Single+Rst” OR “Multi+Rst” OR “Hold+Rst”, and have the Stage’s GATE TYPE switch in the bottom setting (unfilled rectangle) on the physical panel. Send GATE out to VCA.

Note:
While the rests (controlled by your gate output) are happening, there will still be voltage present at your Pitch output… its value is determined by the stage sliders combined with the Rest Pitch setting.

Some ideas if the gate still stays high (lit) when you want it unlit…

  • Double check that your Trk Out Swap parameter is not being triggered somehow by a CTRL knob, AUX input, or MOD lane.

  • If you’re willing to wipe your Track and Stage customisations, consider trying an “Init preset…” .

  • Reply again, so a more advanced user can weigh in.

On the other hand if the gate out LED goes correctly from lit to unlit when the sound should end, then Metropolix is acting how you expect, and the issue could be related to things like this:

  • your gate out is triggering an envelope that is longer than the stage length, then this envelope keeps your VCA open after the LED goes unlit.
  • your VCA offset knob is turned positive so the control voltage (envelope + offset) can never reach zero
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#3

Thanks @zilvar, you gave me the clue, and I figured it out. The gate out LED was toggling correctly from lit to unlit when the sound should end, as in one of your scenarios. Palm to forehead, I then ran the pitch output from Metropolix through a filter, and sent the gate out from the Metropolix to the gate input of the filter, and yah, got it.

Thanks!

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#4

Good start,
So now you have a gated Pitch CV, which works OK. During the rest your Pitch CV is going to zero, meaning your sound source is being tuned to the lowest frequency it can produce. That could even sound really cool with some “slide”. But you may be able to skip the filter, tho, and just set the Metropolix stage slider to the lowest note for similar results or a slight variation.

It is worth experimenting with managing the audio amplitude instead of the Pitch voltage.

  • Metropolix PITCH Out (directly) → Sound source tuning jack (“Pitch”, “1v/Oct”, etc)
  • Sound source OUT → filter IN
  • for a quick and dirty test, Metropolix GATE out into your filter’s gate input (same as your described patch)

More commonly (because gates are abrupt, and gating audio amplitude can introduce audible harshness (clicks) at onset/offset) you would send Metropolix GATE out to trigger an envelope that shapes the Gain level of a VCA. It sounds like your filter has a built in VCA channel, in which case you’d be looking to send envelopes to a “level” or “gain” jack, rather than “gate”. You could also use the envelope to shape the filter cutoff frequency to produce a different sounding transition to the rests stage.

Could be that your filter’s gate input has built in circuitry to prevent the harshness of applying gates to audio amplitude. In that case the “quick and dirty” will sound just fine (no noise or clicks)

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#5

This is great info thanks @zilvar, just one clarification.

By default Metropolix will HOLD the PITCH output at where ever the last non-rest stage left it. This behaviour can be changed to UPDATE (in the Track Menu) which will update the PITCH output with the Slider or Pitch value, but it does not just go to zero, unless you set it up that way.

#6

hmm, I may still be wrong, but I think we must be interpreting fresco’s patch differently. We did touch on the Rest Pitch option earlier in the convo too but,

When fresco says

I took it literally that the Metropolix PITCH out is going into the Filter “Input” and sending the filter “output” to another sound source’s 1v/Oct. Which is why i called fresco’s setup a gated Pitch CV.

If the filter is self oscillating and Pitch CV is being used by the Filter’s 1v/oct … then everything would of course work differently. That does sound more likely, huh. Thank you for catching this.

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#7

I’m merely commenting on the behaviour of the PITCH CV outputs on Metropolix and what to expect from them.

Where y’all patch them is up to you :slight_smile:

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#8

I’m with you now. Thanks. My suggestion to try a very low pitched Metropolix stage is a stretch from the Topic title and the description was skimpy.

For anyone willing to try, the idea was for a similar sounding variation like a grace note or very quiet stage, and not to imply Metropolix would be producing zero volts (apologies!) nor recalibrated (cool!). From there, I figure it depends what you want the GATE to do, since the “shusshing” is being faked by pitch control, either (1) just enable it (non-Rest) if you have use for it HIGH (on), or (2) Still want it LOW (off) to match? Keep the stage in rest mode and force UPDATE through the Track’s Rest Pitch setting.

#9

Hi @zilvar, thanks for all the input on this thread! Yes, you were correct in your understanding with

I took it literally that the Metropolix PITCH out is going into the Filter “Input”

#10

Awesome, I’ll try all of the above!

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