# GuitarMidi-lv2 version 2.0

**URL:** <https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108>\
**Category:** Software\
**Tags:** midi-controllers, midi\
**Created:** [May 6, 2026, 3:45pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108 "2026-05-06T15:45:58Z")\
**Posts on this page:** 19\
**Page:** 2

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**Author:** ![riban](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/riban/32/2331_2.png) [@riban](https://discourse.zynthian.org/u/riban)\
**Post date:** [May 19, 2026, 7:18am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/22 "2026-05-19T07:18:39Z")

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My initial benchmarking shows this may not be viable (in its current form) on zynthian. Running GuitarMidi-lv2 with a light-weight synth, like MDA e-piano consumes a lot of CPU. It looks like it is using 200% CPU - that is based on each core providing 100%, so 50% of available CPU, just to run the audio to MIDI converter. I appreciate the processing it is doing is substantial but I don’t think it would work on zynthian very well. I look forward to seeing if there is any improvement in this.

[Edit] I enabled `dtoverlay=vc4-kms-v3d` on V5 to see if GPU might help… it didn’t. Same high CPU usage.

I also suggest you document the parameters. There are 4 params that may be adjusted but it is not clear how to use them. I tried to systematically adjust them all but couldn’t get the note detection under control.

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [May 25, 2026, 12:34pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/23 "2026-05-25T12:34:52Z")

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Thanks for testing. Have you also tried it on linux on a pc?

I managed to get it running on the MOD Dwarf, at least in principle. It needs heavy optimizations though and I’m not quit sure how low I can get the latency. I think that it will be enjoyable when used with synths loaded with slower patches.

If you’d like to support me and my efforts you can donate to my github sponsors [https://github.com/sponsors/geraldmwangi](https://github.com/sponsors/geraldmwangi)

or my paypal (EU-Only)

[https://www.paypal.com/donate/?hosted\_button\_id=7ELJYWWJ2BKRQ](https://www.paypal.com/donate/?hosted_button_id=7ELJYWWJ2BKRQ)

I’d like to port it to the anagram from dark glass, the mod duox and the zynthian,

but I have to purchase those first.

Thanks,

Gerald

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**Author:** ![bambalaya](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/bambalaya/32/14345_2.png) [@bambalaya](https://discourse.zynthian.org/u/bambalaya)\
**Post date:** [May 26, 2026, 8:25am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/24 "2026-05-26T08:25:54Z")

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Have you tried lowering the input stage to 1.7v max???

Doesn’t matter for PC, but Zynthian runs on Raspberry and I don’t know if it could be relevant or not, but many versions do not make use of any external USB-audiocard device.

Might that be one problem???

Tnx for your work!

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [May 26, 2026, 9:04am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/25 "2026-05-26T09:04:08Z")

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In the next 2-3 weeks Im optimizing GuitarMidi for cpu performance across pc and mod dwarf. This should benefit the zynthian as well. I’ll get me an extra rpi 5 to test on that too

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [May 26, 2026, 9:07am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/26 "2026-05-26T09:07:01Z")

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I dont know what you mean, since I dont own a zynthian. The high cpu usage is also observable on other arm devices and even older intel based laptops. Im on it!

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**Author:** ![maartmaart](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/maartmaart/32/12972_2.png) [@maartmaart](https://discourse.zynthian.org/u/maartmaart)\
**Post date:** [May 26, 2026, 2:40pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/27 "2026-05-26T14:40:23Z")

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Hi @jimsondrift ,

Are you soure it ever will run 6 voices polyphony om Moddwarf? I have my serious doubts…  
Anyway good luck!

Cheers,  
Maarten

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [May 26, 2026, 3:10pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/28 "2026-05-26T15:10:34Z")

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I won’t promise anything but I think so. The plugin has two stages: the filterbank and the neural net.

Both have roughly around the same amount of operations, flops.

The neural net is loaded by the highly optimized tflite lib. The filter bank is in part my own code and totally non optimal. Im working on that part so that it is equal or even faster than the neural net. Then the plugin will run in full polyphony

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [May 28, 2026, 2:20pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/29 "2026-05-28T14:20:33Z")

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# New version v2.1 of GuitarMidi-lv2

## CPU performance

- implemented performant filterbank  
- removed dspfilters submodule

## Detection

- added note detection volume to reduce false positives

## Other improvments and new contributors

```
- By Tomtiger66: Fix hardcoded tflite path: use LV2 bundle_path instead of /usr/lib/lv2 

```

Get it at [Release Performance boost · geraldmwangi/GuitarMidi-LV2 · GitHub](https://github.com/geraldmwangi/GuitarMidi-LV2/releases/tag/v2.1)

## Update regarding ARM

I’ve improved the plugins runtime performance on the cpu so that it runs on the mod dwarf without xruns

However latency is still very high ~50ms. This is due to the neural net having ~800k parameters. I cant release it this way. I have thought about the implementation of a monophonic but that is an entirely different model that needs to be designed, trained and tested. taking time away from my task to provide rock solid polyphony for linux and linux-powered devices. And in some way this move feels backward since the core tenet of the plugin is that you should be able to seemlessly switch from solos to chords and this I have achieved.

There is hope though. I have ordered the coral usb accelerator [Google Coral USB Accelerator - Edge TPU ML - ARM Botland - Robotic Shop](https://botland.store/google-coral/16911-google-coral-usb-accelerator-edge-tpu-ml-arm-cortex-m0-193575021935.html) for which tensorflow lite has support, I think this is the way forward, my plan is anyway to support new guitar gear that have tensor processing units. Thanks for your understanding

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [June 19, 2026, 2:40pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/30 "2026-06-19T14:40:42Z")

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# GuitarMidi-lv2 Release v2.2 Expressivity is out

This is a big one:

- Added velocity tracking, its called “Expressivity”
- Added input gain control
- Plugin finally operates with any buffer size and any samplerate
- some bugfixes  
Get it at  
[Release Expressivity · geraldmwangi/GuitarMidi-LV2 · GitHub](https://github.com/geraldmwangi/GuitarMidi-LV2/releases/tag/v2.2)

Thanks to Fons and Tim for their help

Rock on  
Gerald

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**Author:** ![jtode](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jtode/32/8679_2.png) [@jtode](https://discourse.zynthian.org/u/jtode)\
**Post date:** [June 21, 2026, 8:43am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/31 "2026-06-21T08:43:02Z")

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As far as Zynthian, all you need is a Pi - you won’t have the full V5 UI available, but as far as testing your software’s function, you’re good to go, there’s a screen-only mode.

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [June 21, 2026, 9:03am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/32 "2026-06-21T09:03:08Z")

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Can the zynthian os run lv2 plugins with generic ui? Guitarmidi doesn’t have a custom ui yet

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**Author:** ![riban](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/riban/32/2331_2.png) [@riban](https://discourse.zynthian.org/u/riban)\
**Post date:** [June 21, 2026, 9:24am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/33 "2026-06-21T09:24:26Z")

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Zynthian runs LV2 headless and presents the parameters consistently in the zynthian UI. If the LV2 has a native GUI **and** VNC is enabled **and** it is not explicitly disabled in zynthian code (some native UIs cause problems) then you can also access the native UI via VNC.

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [June 21, 2026, 1:19pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/34 "2026-06-21T13:19:38Z")

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Thanks. Just like mod dwarf. Does it use mod software under the hood?

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**Author:** ![riban](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/riban/32/2331_2.png) [@riban](https://discourse.zynthian.org/u/riban)\
**Post date:** [June 21, 2026, 5:00pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/35 "2026-06-21T17:00:22Z")

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> [@jimsondrift](#):
>
> use mod software under the hood?

No! Although you _can_ run mod-ui as a _special_ engine it is strongly discouraged.

We use jalv as the LV2 host and integrate with our our controllers.

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**Author:** ![riban](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/riban/32/2331_2.png) [@riban](https://discourse.zynthian.org/u/riban)\
**Post date:** [June 26, 2026, 5:28pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/36 "2026-06-26T17:28:56Z")

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I compiled the LV2 from source. (There are no release packages for arm64.) Its detection is much better. Using the bridge pickup on a Squire Telecaster it tracks fairly well from low E to 11th fret high E string. It accurately detects chords through this region too. That is all very impressive. It does driver all 4 cores hard with each core sitting about 70% and the fan being driven on to full power. There is too much latency in the detection though. I have not measured but it feels like about 100ms, too slow for almost all uses.

I tried this again because I watched some very good videos by lofileif, including  
[Best MIDI Guitar solution in 2026 - Fretboard scanning vs Pitch-to-MIDI](https://www.youtube.com/watch?v=t1adZ8HPYus) which gives a good insight to MIDI guitar options. I rebuilt my Roland hex pickup MIDI guitar and compared it with this software neural network solution. The hardware still wins, but it is amazing what can be done in software. A few years ago you would have been burned as a witch! 😉

[Edit] When in bypass, 3 cores reduce to near zero but the 4th core goes to 100%. Is this a bug in the plugin?

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [June 26, 2026, 11:18pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/37 "2026-06-26T23:18:51Z")

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Thanks a lot for testing. The current version, while working well on PC, is hefty for the pi, I am aware of that. I am looking into some options on bringing down latency on weaker CPUs. Have you tried it on PC?

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [June 26, 2026, 11:20pm UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/38 "2026-06-26T23:20:20Z")

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I haven’t noticed any issues regarding the bypassing on pc

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<div class="post-metadata">

**Author:** ![riban](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/riban/32/2331_2.png) [@riban](https://discourse.zynthian.org/u/riban)\
**Post date:** [June 27, 2026, 10:04am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/39 "2026-06-27T10:04:11Z")

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I do not use a PC. I tried bypassing other LV2 plugins on zynthian and did not see the same behaviour. Zynthian has a complex bypass mechanism using a forked version of jalv so you may not be triggering it in the same way.

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**Author:** ![jimsondrift](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/jimsondrift/32/14437_2.png) [@jimsondrift](https://discourse.zynthian.org/u/jimsondrift)\
**Post date:** [September 24, 2026, 11:26am UTC](https://discourse.zynthian.org/t/guitarmidi-lv2-version-2-0/13108/40 "2026-09-24T11:26:59Z")

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Hi All,

The new forum at [lodi-audio.com](http://lodi-audio.com) is online ([Forum – Lodi Audio](https://www.lodi-audio.com/forum)).

You can sign in and discuss all matters GuitarMidi-lv2 there.

User management is securely handled by moonbase.sh, no user identifiable data is stored on my server. The names and emails are at moonbase.sh

Its a good place for me to get signal from the users of my plugins.

Just keep it nice and friendly.

There is a lot more to come in the next weeks, so stay tuned!

Yours,

Gerald

> **[Lodi Audio](https://www.lodi-audio.com)**
>
> Lodi Audio – professional audio plugins for producers and engineers.

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