LxPG — an adjustable sample-based LPG

Hi all,

Here’s my attempt at making an LPG that allows for a few useful adjustments.

The “vactrol ring” and “CV Both” are using a sample of the lower part of actual Make Noise LxD’s vactrol response on a +10v offset when strike is triggered — to achieve exponential envelope.

It’s pretty simple but i’m sure i’ll be improving it.

CV Both — equivalent to level control on Optomix or Terminal (VCA/VCF open/close). It is mapped to the reversed vactrol response sample to make it exponential, like on most LPGs.
Strike — feed it triggers / gates.
Damping — controls the speed of the vactrol response sample playback, effectively affecting the “ring” time. 0 is original speed (that seems too long-ish).
VCA Bias and VCF Bias — offsets tuning the response to make it brighter, darker, more “VCA-y” or more “VCF-y”. Experiment! I picked up ranges that seem useful to me but you can always “Edit Controls”.
VCF Q — filter resonance. Again, I limited ranges to what seemed useful to me.

put the .unit file anywhere
the “vactrol” folder goes into “ER-301/samples” folder in the root of the SD card.
Again, the path should be “/ER-301/samples/vactrol”

CPU level is at 13% now, i’ll think about what I can do to reduce it.

please let me know what you think! i was able to coax pretty convincing LPG stuff from it.

v 0.2 — LxPG.zip (1.2 MB)
v 0.3 – [repackaged for firmware v. 0.6.x] – lxpg.pkg.zip (1.2 MB)
(unzip, put into ER-301/packages and install via admin / package manager


Looks cool. Thanks for sharing. Looking forward to trying it out!

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Thanks, let me know what you think!

wow!!! tomorrow i’ll be testing it and will give some feedback! (i have optomix v1, lxd and streams to compare).
thanks for sharing!!!

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thanks! certainly there’s a lot of uniqueness to the real LPGs that can’t be replicated — but that’s not the goal, i have the LxD and the mk1 Terminal too, as well as the 208r and they all sound great and different. but as a small aux thingy, especially for live setups the LxPG can be useful i hope.

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simply beautiful! i just loaded up a sine vco with some feedback and the lxpg, works really well and retains the lovely punchiness of real plucked lpg’s!
congrats! this is very useful!

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thanks! i’m really happy to hear that!

i hope one day i learn middle layer to make more efficient units.

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Love the concept of this – such a neat way of emulating an LxD. Really inspiring!



Hey @joe_biomassa this is a lovely sounding unit, thank you!
How could an envelope be introduced to get that strike gate/trig and turn it into a suitable signal for cv both? That way there would be no need for external envelope.
Maybe it’s already there, but I could just tweak the tail of that.
Does it make sense?

Hey thanks, happy you like it!

All strike input does is triggering the sampled envelope derived from the vactrol response of an actual Make Noise LxD. So i’m guessing the best way to tweak it would be replacing the sample itself! Or patching an external envelope into CV Both.

Yes, but I can also use an envelope and send it to cv both, right? Instead of using strike.
What if I feed, to cv both, a gate that still needs to be enveloped before going to the rest of the unit

Really sorry but I’m not sure I understand. That unit is focused on incorporating the real vactrol’s response into the ER-301 context. I’m sure what you need can be done but I don’t quite grasp it.

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