Raspberry Pi for guitar modelling, anyone?

[Sedaxel]

24 / 3 Buffers is completely usable...

Wow... Helix performs quite well there. I think there must be something wrong with my Pi, though. Always suspected it because of the cpu bouncing all the time.

With my hifiberry, I must set it to 32/2 to be useable... and still with some risk of derailing. That said, it gets very good RTL (but it´s a dedicated interface, directly connected to the GPIO port.

 

[Mike Oliphant]

Wow... Helix performs quite well there. I think there must be something wrong with my Pi, though. Always suspected it because of the cpu bouncing all the time.

With my hifiberry, I must set it to 32/2 to be useable... and still with some risk of derailing. That said, it gets very good RTL (but it´s a dedicated interface, directly connected to the GPIO port.

I think going below 64 is likely a bad idea unless you've got a lot of CPU headroom available. 64 is already very good latency, and the lower you go, the more significant the per-buffer overhead becomes. Also, many DSP operations are designed to operate efficiently on blocks of data and you start to mess with that more and more as you go below 128 samples.

 

[Sedaxel]

I think going below 64 is likely a bad idea unless you've got a lot of CPU headroom available. 64 is already very good latency, and the lower you go, the more significant the per-buffer overhead becomes. Also, many DSP operations are designed to operate efficiently on blocks of data and you start to mess with that more and more as you go below 128 samples.

Agree. Lately I put it on 64, yeah. If I remember correctly, it made a RTL of around 5 ms, which is perfectly fine anyway.

 

[Los-D]

Probably like everyone here on this forum, I've been looking into NAM lately. Not because I'm unhappy with my Helix LT, no, but somehow the quest for tone is never over. I definitely didn't want to use my PC, so I fired up my iPad again. And yes, it's great what's happened recently: TH-U remains great, but now also opensource stuff like Chowdhury DSP BYOD, with which you can also run NAM models, and then especially Tonex and Gigfast Lite. But... they all eat up resources, Tonex is totally buggy and Gigfast Lite keeps crashing as a plugin in Loopy Pro.

So I remembered that I had recently bought a Raspi (4B with 2G RAM), but I hadn't touched it yet for fear of falling into another time consuming rabbit hole of tinkering... and... of course I fell into it. First of all, I had to remember the basic Unix commands that I hadn't used in 20 years, and then I had to realize that there is a huge Unix audio community and everything is incredibly confusing and then audio under Linux: alsa, jack, pulseaudio, pipewire... A few days later I had a first overview (if that had been working time for a client, I could have bought a box full of Dimeheads). Whatever. Then I found some possibilities, tried Modep with Patchbox OS - unfortunately too resource-hungry, as is Zynthian

And then a few days ago I found Pipedal (https://rerdavies.github.io/pipedal/): A standard PI-OS installation, install Pipedal, two or three commands to get around a few bugs (that seems to be mandatory in this world) and you're done! Pipedal is a general lv2 host with a few effects and amps already built in. It already includes a version of the NAM plugin (https://github.com/mikeoliphant/neural-amp-modeler-lv2). Super stable and, what's more, high-performance. Great minimalist GUI. Pipedal installs a web server so you can control it from your mobile. You can use almost any profile (the only ones that don't work for me so far are @Slammin Mofo's high accuracy profiles).

I also found another great lv2 Nam plugin: Ratatouile: https://github.com/brummer10/Ratatouille.lv2, runs perfectly under Pipedal. With Ratatouille you can load two profiles in parallel and blend them seamlessly without increasing the processor load (you get two for the price of one). So you can go seamlessly from clean to crunch.

Yesterday I connected the Pi to the Helix and was impressed. Works perfectly. Round trip latency of 5ms - mind you, that's the full latency, measured with a loopback cable and a complex Helix preset. So Helix + Pi. My Helix can now do NAM! For 60 Euros! I'm thinking about buying a Pi 5 now, let's see how it runs

I would really like to know if others here are playing around with a PI (@Sedaxel ) and how you are using it!

I only have an older 3B. Any idea on performance on it? (Will need to check eventually)

 

[panhardleft]

@Mike Oliphant: I'm trying to get stompbox to work - but so far I've had a problem. Stompbox-jack runs on the Raspi after I installed Jack and started the Jack server. However, Stompbox UI doesn't run on either my Win 11 or my Win 10 machine: When I enter the server name, the program simply closes. Apparently the server is found, because if I enter an incorrect server name, the input window pops up again. Only when I enter the correct name does it close again.

In the console window running stompbox-jack I see the following:
Start listening for connection
Connection received
Got message: Dump Config
Plugin Boost already loaded
Plugin Screamer already loaded
Plugin Compressor already loaded
Plugin Fuzz already loaded
Plugin AutoWah already loaded
Plugin Wah already loaded
Plugin Phaser already loaded
Plugin Vibrato already loaded
Plugin Flanger already loaded
Plugin Chorus already loaded
Plugin Tremolo already loaded
Plugin Delay already loaded
Plugin Reverb already loaded
Plugin ConvoReverb already loaded
Plugin NAM already loaded
Plugin NAMMulti already loaded
Plugin EQ-7 already loaded
Plugin BEQ-7 already loaded
Plugin HighLow already loaded
Plugin NoiseGate already loaded
Plugin SimpleGate already loaded
Plugin Cabinet already loaded
Plugin Level already loaded
Plugin Input already loaded
Plugin Master already loaded
Plugin Tuner already loaded
Plugin AudioFilePlayer already loaded
Plugin AudioFileRecorder already loaded
Got message: Dump Config
Plugin Boost already loaded
Plugin Screamer already loaded
Plugin Compressor already loaded
Plugin Fuzz already loaded
Plugin AutoWah already loaded
Plugin Wah already loaded
Plugin Phaser already loaded
Plugin Vibrato already loaded
Plugin Flanger already loaded
Plugin Chorus already loaded
Plugin Tremolo already loaded
Plugin Delay already loaded
Plugin Reverb already loaded
Plugin ConvoReverb already loaded
Plugin NAM already loaded
Plugin NAMMulti already loaded
Plugin EQ-7 already loaded
Plugin BEQ-7 already loaded
Plugin HighLow already loaded
Plugin NoiseGate already loaded
Plugin SimpleGate already loaded
Plugin Cabinet already loaded
Plugin Level already loaded
Plugin Input already loaded
Plugin Master already loaded
Plugin Tuner already loaded
Plugin AudioFilePlayer already loaded
Plugin AudioFileRecorder already loaded
Got message: List Presets
Got message: PluginOutputOn
Got message: List Presets
Got message: PluginOutputOn
Got message: List Presets
Got message: Dump Program
Got message: List Presets
Got message: Dump Program
Got message: SetParam Tuner Enabled 0
Set on: Tuner
recv failed with error: 104
Connection closed
Start listening for connection

 

[panhardleft]

I only have an older 3B. Any idea on performance on it? (Will need to check eventually)

I fear that running NAM-profiles will be difficult. But try it! So far I would recommend Pipedal, since it's very easy to install an run. Right now, I'm struggling to get stompbox to work, so I can't compare. But I can tell you that Pipedal is much more performant than modep, and I assume you can use the other "blocks" on the 3 just fine.

 

[panhardleft]

This sounds like I need a PhD.

That's part of the fun!!

 

[likitlikeyoulikeit]

That's part of the fun!!

Not gonna lie....i have been entertaining the Pi for making a midi loop switcher from scratch.

Effects and NAM seem fun and neat.....but not something reliable for my use. But I like fiddling with stuff too. So that's cool.

Anyone here make a midi controlled loop switcher? With the Raspberry Pi?

If so....any recommendations?

Not trying to thread Jack.

Site I used for my reference project.... haven't started yet.

MIDI-Controlled Loop Switcher | Scientific Guitarist

A DIY 5-loop, MIDI-controllable loop switcher for electric guitar, bass, and other instruments.

scientificguitarist.wixsite.com

 

[Mike Oliphant]

@Mike Oliphant: I'm trying to get stompbox to work - but so far I've had a problem. Stompbox-jack runs on the Raspi after I installed Jack and started the Jack server. However, Stompbox UI doesn't run on either my Win 11 or my Win 10 machine: When I enter the server name, the program simply closes. Apparently the server is found, because if I enter an incorrect server name, the input window pops up again. Only when I enter the correct name does it close again.

I recently made some changes to the wire protocol that might be causing this.

If you building stompbox on RPi from the latest source, but downloaded the latest StompboxUI release (rather than build it), then they'll be out of sync. I should do a new StompboxUI release. Meanwhile, you can always get the latest by building it yourself, or by downloading the binary from the latest github build - currently here:

Merge branch 'master' of https://github.com/mikeoliphant/StompboxUI · mikeoliphant/StompboxUI@80a957e

Remote GUI and VST3 plugin for Stompbox guitar simulation - Merge branch 'master' of https://github.com/mikeoliphant/StompboxUI · mikeoliphant/StompboxUI@80a957e

github.com

If you continue to have problems, can you open an issue on github? Thanks!

 

[Mike Oliphant]

@panhardleft There was actually a bit more of a problem. I've pushed fixes to both the stompbox and StompboxUI github repositories.

I'll push a new StompboxUI release soon, but for now you should be good if you build the latest of both.

 

[Mike Oliphant]

For those who may be interested, Stompbox is also available as a Windows VST3 plugin. No Ph.D required.

Just download the "StompboxVST3Plugin.zip" archive from here:

Release Release v0.1.10 · mikeoliphant/StompboxUI

Add support for File type parameters Add menu option to open folder for file parameters (ie: NAM model, cabinet/reverb impulse, etc.)

github.com

This is what it looks like: