Geek Funk Labs

Category: Thoughts

Musings/opinion/discussions about tech

  • Vortex Wireless 2 Teardown

    I decided to open up my keytar for the purpose of cleaning, but also to see if I could figure out what kind of MCU it has with the idea of possibly writing my own firmware. I’ve got a few reasons for this, mostly to do with the pads. First, when switching between presets on the Vortex, the state of any CC toggle pads depends on the state they were on the previous preset, which is dumb. Worse, the LED state doesn’t update to reflect this, they just always display their OFF color. Each preset should have independent storage of its pad states, so you can flip between them to trigger different loops, effects, etc. This doesn’t seem like it would be hard to code and would just be a few extra bits of memory, so it seems annoying they (Alesis) wouldn’t write the code this way.

    I would also like to be able to send MIDI messages to the Vortex to change its pad states, to reflect what’s going on with my DAW or sound module (i.e. SquishBox obv). This could be CC or SYSEX. Finally, like many MIDI controllers, the software for programming the Vortex has no Linux version. I could do what some have done for other MIDI controllers and try to decode the sysex by spying on the data when programming the Vortex from Windows using WireShark, but if I wrote my own firmware I wouldn’t need to.

    I’m including pictures of the Vortex internals here. Hopefully others will find them useful, even though my budget Samsung phone’s camera is a bit blurry in spots. I did manage to locate the MCU, which turns out to be a fairly run-of-the-mill ARM STM32F103R8 – which web searching tells me you can find nice dev boards and tutorials for. There’s even an 8-pin port labeled “program” broken out on the Vortex PCB, so there might be some slight possibility of me figuring this out. I’d have to figure out how the _many_ peripherals work (wireless USB, accelerometer, various button boards) or reverse engineer the firmware (link provided for my future reference), but maybe someone smarter than me can save me the effort 🙂

    Final thought: It’s great that we have lots of USB MIDI controllers available, some very affordably priced, but the software provided for programming them is usually pretty painful. They all seem to work by sending some cryptic sysex messages back and forth that the manufacturer generally won’t bother to share with you. I think the way to make them user friendly would be to design them as dual USB devices – MIDI device+mass storage device with a tiny partition containing an easy-to-parse text file with all the settings. You could still write a user-friendly interface for casual Windows/Mac users, but this would make it easier for power users to write their own interface or change the settings by hand. I could just build my own MIDI controller around a Raspberry Pi Pico that does this exactly. Or manufacturers could at least provide their silly sysex communications protocol in a PDF online somewhere.

    all the things
    Keybed – you can see the aftertouch is just one long FSR
    I/O board
    neck controls
    some sort of pinout legend on the main PCB
    accelerometer
    MCU on the main board, programming port is the white 8-pin header at the top
    most of the main PCB

  • Post Knobcon Recap

    It was an interesting three days at Knobcon. I played with a lot of different gear, learned some stuff, saw some cool performances, met lots of people. Everyone I talked to was super friendly and relaxed, and willing to let me bombard them with questions about their gear or their business. I was surprised to meet a lot of exhibitors there who are just one-person operations like me – some who have designed small DIY gadgets like the SquishBox, and some who are putting out pro-grade synth modules and keyboards. It’s surprising how far you can go on your own.

    Performances: The Friday Night reception had a bunch of great acts. The highlight for me was Too Mere playing the Synthstrom Deluge – he played it handheld rather than hunched over it on a table, and his dancing around while he poked all those flashy buttons and morphed from one beat to the next made for an entertaining show. The other acts were a good opener for the weekend too, and after meeting with some people and chatting I found myself just leaning back in a contented zen state watching the video effects and letting the synth textures wash through my head. Saturday night’s shows gave me more synth to enjoy. I had a good time watching the Supper Club jam in the pavilion, seeing musicians jam out some more old-school funk tunes like I’m used to, with a mix of synth and non-synth instruments.

    Workshops: I went to a lot of these. Scott Danesi took us through his journey of creating a modern custom pinball machine with a kickin’ synth soundtrack, and it made obvious the shared skills and DNA of a project like this and what goes into creating synths and music gear. Mike Beauchamp from Therevox shared a history of the Ondes Martneot, a vintage monophonic synth that uses a string-operated potentiometer to set note frequency, and his quest to recreate it in modern form. Marc Doty gave a history of polyphony in synthesizers, ostensibly focused on how we should think about the definition of certain synth terms, but really I think a discussion of what a synthesizer should do. How should we control it? How should it reproduce notes and be able to articulate them?

    I think the big takeaway for me from the weekend was that I am a huge noob when it comes to synths. This wasn’t news to me, but although I conceptually understand how something like a rackmount synth or a Minimoog works, the complexity of the actual things are mind-boggling, and it’s impressive to see what a huge community of musicians there is that’s into them. Then there’s the proliferation of grooveboxes, samplers, video effects – it’s amazing to see the different ways people make music.

    It also makes me think about my place in all of it. I’m interested in the theory of synthesis, and might even pick up some kind of all-in-one modeling synth keyboard to play around with at some future point, but I don’t plan to get heavy into analog synthesizers, constructing new sounds from raw oscillations and using them in my music. I’ve always enjoyed software synths and MIDI, and I feel like with a software synth you have the flexibility and versatility to create some truly amazing sounds, even though the oscillations aren’t “pure” as they are in analog electronics. Also, I want my sounds to be free of a specific gadget, to be expressible as ones and zeros of a sample or code. That’s why I made the SquishBox – it’s a software synth in a box, but the same code can run on a desktop machine in different OSes and produce the same sound. Maybe there’s room for a soundfonts talk at a future Knobcon?

  • On Being a Hack

    Putting together lessons and videos for Fluidsynth has been instructive, as these things always are. Nothing exposes the mistakes in my code or errors in my thinking like trying to teach to someone else, which something I’ve always found in my more traditional teaching role as well. It’s useful but also a humbling yet comforting reminder that (certainly) I (and probably everyone else) go through life trying to understand and get better at a lot of things we have to pretend we’re good at. That’s one reason I like working on these musical gadgets so much – I feel like I can create something worthwhile and useful even though I am by no means pro at any of the skills involved – coding, engineering, etc.

    We’re all hack to varying degrees at just about everything, and in the end what matters is what you create.