gsliepen 11 hours ago

I wrote a software synth myself with the intention of running it on Raspbery Pi 3 / Zero 2. Those are actually quite capable processers; sound synthesis requires very little RAM, both code and for maintaining state, so everything fits in the rather tiny cache. But at the same time, while these Pis use "little" cores, the maximum throughput of NEON instructions is actually the same as for the corresponding "big" cores like the Cortex-A72. With four cores, you can do in the order of ~10 GFLOPS 32-bit FMA instructions. With a sample rate of 96 kHz and 32-note polyphony, you theoretically have a few thousand FMA instructions per note to spend.

  • mrob 8 hours ago

    To put this into perspective, five FMAs per sample is enough to implement a biquad filter. This is a very common DSP building block that can implement an idealized version of any of the 2nd-order filters that were ubiquitous in analog synths, e.g. high pass/low pass/band pass/notch/all pass. See the famous Audio EQ Cookbook for examples:

    https://www.w3.org/TR/audio-eq-cookbook/

    By chaining various combinations of EQ and non-linear distortion (lots of ways to implement this, probably involving more FMAs) and you can build very good simulations of common analog synth signal paths.

    Note that gsliepen's example sample rate of 96 kHz is perfectly reasonable in this context; it's more than you need to exceed the limits of human hearing, but it's common to oversample your signal for processing to avoid problems with aliasing.

milesvp 3 hours ago

For more context, dsp chips historically were how you could get better better performance than was typical in the embedded space. At a time when you had sub 100Mhz typically in a chip that would be used in musical equipment dsp chips were super useful because they had many op codes that could be done in one cycle that might take many multiples of that in a general purpose chip. One prime example is add and accumulate. This meant that effectively, if you had an 80Mhz dsp doing calculations for you, you effectively had a 160-240mhz equivalent in your hotpath. This bump up in processing is necessary to meet hard realtime deadlines in audio processing at 48khz stereo processing.

Now, processors are so fast and cheap, that the need for dsp is way down. I personally ported the firmware for a popular pedal where the chip used was no longer available at quantity, and while it was tricky to get the same performance on a dual core 240mhz processor with floating point coprocessor, as the 96Mhz processor it was replacing, I just had so much compute, that I was able to port all but the gnarliest simultaneous effects on a chip that cost $6 cheaper but also came with enough ram to not need that $3 component either. And I can tell you, saving $9 dollars off a BOM means the product can retail at least $50 cheaper in an industry where volume matters a lot (no pun intended).

We have passed the inflection point where dsp chips are generally not worth the cost in most audio equipment. I’m not sure I’d use a raspberry pi, their reliability is not what I’d want in my products, but a similar single board computer? maybe. I’m not sure where linux realtime kernals are at the moment, ignoring the added complexity of a full linux running to process audio, audio requires hard deadlines. You will hear pops and other artifacts if you miss these deadlines, and buffering audio is also not something you can do for long, artists can feel delays in the ms. But, a single board computer running at ghz speed, gives an awful lot of compute so long as the OS can gaurantee your audio thread won’t get starved.

  • wvlia5 2 hours ago

    I want to make devices too. I have a few in my pipeline, but never sold any. 2 for music, 1 medical, 2 for house construction.

    • lostlogin an hour ago

      I can see why you wouldn’t post it, but I’d love to know what you’re thinking - medical in particular.

      I work in the field and clunky, shit software is the norm. In particular, radiology information systems (RIS) just kill me. How are they so crap?

      • wvlia5 14 minutes ago

        I'm making a vape, just like nicotine vapes, but it has a computer that allows you to 1-select a specific dosage (say 5mg) or 2- select a target effect intensity, and deliver a sequence of doses to sustain the target, based on a pharmacodynamic curve. (not for nicotine)

  • aswanson 2 hours ago

    Facts. Dedicated dsp chips face a shrinking market for audio with sbcs being so powerful these days.

boriskourt 11 hours ago

Max MSP has RNBO [0] which provides a Pi image, and a quick deploy path for patches. I've used it for a few art installations, and the versions from this year have been super nice. Basically, you can design and test audio on your regular dev machine and quickly deploy to the PI. You don't need to mess with any Linux audio nonsense.

People also use this to make unique pedals.

[0]: https://rnbo.cycling74.com/

Joeboy an hour ago

I'm feeling a bit inspired to build something, but not inspired enough to spend £450 on a Zynthian box. What would be awesome would be some sort of standard hardware platform with audio in / out that costs closer to £100 (for about which I can get apparently get a dev kit with CM5 + IO board + case, but no audio).

jscheel 6 hours ago

I recently got a Daisy Pod (https://daisy.audio/product/Daisy-Pod/). It supports a few different runtimes, including a max/msp runtime and a Pure Data wrapper called Plug Data. It's a pretty neat little device, even though the documentation could use some work.

  • LambdaComplex 2 hours ago

    I've been working on building something using a Daisy Seed lately. Pretty amazing that I can have interesting sounds (and effects) generated in just ~200 lines of C++.

    And you're absolutely right about the documentation.

MomsAVoxell 5 hours ago

I recently started a small synthesiser project, specifically to teach myself some SIMD:

https://github.com/seclorum/simdsynth

Its an 8-voice polyphonic synth with 1 oscillator per voice, a filter, an LFO, and EG's for the Osc and Filter.

I've been extremely happy with the performance I'm getting, running on the Raspberry Pi - in both Monome and Zynthian systems!

Monome and Zynthian are both game-changers for FOSS audio hackers. I have both running side by side and they are just a pure inspiration for audio exploration. It's very rewarding also, to be able to put my own code alongside all the other great stuff from both communities.

lolive 13 hours ago

I discovered by pure chance the vast ecosystem of iOS synths apps. And I was absolutely blown away. 90+% of the synths of the past century are available for ~5-20€ each. Connect that to a basic KORG MicroKeys Air [extra cheap, but includes Bluetooth]. And you are the next Jean-Michel Jarre.

[Note: and the amount of tutorial videos on YouTube is huge.]

  • MomsAVoxell 4 hours ago

    I have a room full of synths from the 70's and 80's, two racks full of synths from the 90's, a veritable crap heap of soft synths on various Macs, and a Eurorack corner that threatens to implode my universe .. an as well - my Zynthian and Monome systems are chock full of great stuff, too.

    It's not just iOS.

    Zynthian and Monome provide an AMAZING ecosystem for audio exploration. If you haven't checked that out as well, here's the links:

    https://monome.org

    https://zynthian.org

    That said - I could easily just get another iPad, throw away the room full of synths, wire up my iPads and the Zynthian and Monome systems, and be quite satisfied.

  • vunderba 3 hours ago

    I do the majority of my music composition on a desktop but it can definitely be nice to bring my 37-key midi controller + iPad for doing stuff on the go.

    It's also not entirely uncommon for an App Store synth to offer both an iOS and a native Mac version so always check the store description to see if its universal. The ability to seamlessly bring your tracks over to a more full-fledged DAW on your Mac is really nice.

    Example: Minimoog Model D Synthesizer

    https://apps.apple.com/us/app/minimoog-model-d-synthesizer/i...

  • lastdong 12 hours ago

    GarageBand is free on every iPhone and has a good selection of starter synths, with added DAW capabilities. Bluetooth midi controllers are supported (via bluetooth midi connect App). Using a pi or Arduino to build a midi controller can also be great fun.

    • raffraffraff 7 hours ago

      This is the real competition. I'm not a Mac head but the one Mac in my house that will runs MacOS is connected to my Yamaha piano and runs Garageband. Is there any other software that works as simply as this, on any other platform?

      • vunderba 3 hours ago

        Having grown up with and used the vast majority of DAWs (Logic, Ableton, Bitwig, FL Studio, Reaper, Studio One, etc) - Garageband probably has the gentlest learning curve of any of them.

        And it doesn't hurt that when need more power/features you can upgrade to its big brother Logic Pro X which offers a very similar interface.

      • AlecSchueler 6 hours ago

        Simple in what way? It's a difficult question to answer because in my mind pretty much any software synth on Linux is just plug and play, but I'm guessing there's a technical gap that I'm overlooking due to familiarity.

        What complications do you run into outside of garage band, or you imagine you would run into?

        • vunderba 3 hours ago

          Has the Linux world gotten better in the past decade? I remember audio drivers/latency being a particular pain in the ass. In terms of ease of use from best to worst I'd rank them:

          1. Mac Core Audio (Works out of box)

          2. Windows ASIO (ASIO4ALL or just plugin a Scarlett/MOTU audio interface)

          3. Linux Pipewire

        • klodolph 5 hours ago

          Garage Band is also a DAW; you can record both MIDI and audio tracks. Big library of things like drum loops and basslines you can drop into your project. Big library of sounds, including acoustic instruments, orchestral instruments, drums, world instruments. Good selection of effects. Easy to browse presets.

          I have at various points in my life used Garage Band, Logic, or various Linux software.

        • QuadmasterXLII 5 hours ago

          They might just be old like me- I crashed into ubuntu studio’s ALSA and Jack config like a brick wall in 2012 and never recovered.

          • klodolph 5 hours ago

            I also remember dealing with a nightmare of PulseAudio problems. It took me a long, long time to warm up to PulseAudio after experiencing how bad it was around 2010.

        • fortran77 4 hours ago

          Really? I _still_ can't get sound to work at all on Ubuntu.

    • bigyabai 2 hours ago

      Garageband only has a sampler - there is no subtractive synth engine outside AUs, AFAIK.

  • rjh29 13 hours ago

    For some synths like Blofeld, you're paying $10-20 for something that used to sell in a box for $300. And it's the exact same synth (100% digital) often with a better UI.

    The iPad is a great choice for music - you get the variety of hardware synths with none of the annoying setup (power, midi, audio routing), at a cheaper price, but it still feels more immersive than sitting at a desktop PC and a daw.

    • ofalkaed 10 hours ago

      But they are not the same, if you are a musician going to bars and practice spaces and the like that $300 Blofeld will handle the abuse and accidents much better than a laptop or tablet. No matter what you do and how careful you are, cords get snagged and stepped on, stuff gets knocked over, things get spilled etc etc etc. My Blofeld has taken far more abuse than any laptop or tablet will handle and still going strong 15 years later; three laptops and two tablets later.

      There are things you can do to make computers more suitable for this stuff but it gets expensive fast and less convenient quickly. Toughbooks are tempting, but expensive, rackmount computer can be managed for not much and keeps the computer safe in its rack but now you more and bigger stuff to haul. Taking a disposable approach with rpi or the like is tempting but not exactly ideal. Computers/tablets are great and have their uses but are not a replacement for hardware yet.

      The big problem for me with all things touch screen is that they get confused by water on the screen, which is an issue when it is hot and you are sweating or on a stage with bright lights cooking you. Not an issue if you just want to tap out beats but a serious headache if you want to adjust parameters. Connectors on tablets are also an issue, USB is not a very secure connection and the wireless options are not great. Give me a tablet with a plastic screen, 1/4" ins/outs, can run PureData and will not get confused by water on the screen and I will probably give up my hardware.

      • diggan 9 hours ago

        > My Blofeld has taken far more abuse than any laptop or tablet will handle and still going strong 15 years later; three laptops and two tablets later.

        On the other hand, my Blofeld had wonky unresponsive knobs after just a couple of months, not that they were very good at the first place, who thought having knobs with no tactile feeling of grip was good idea?!

        Personally the biggest win for actual hardware is that it's just more fun to play and use. I've tried various music apps for mobile/tablets and while it's fun for some minutes, that's pretty much it. But then I feel the same with DAWs, it's just not as fun as playing with an hardware drum machine + synth + sampler all hooked together.

        • ofalkaed 8 hours ago

          The encoder issue was fixed with a firmware update, they switched encoders and did not quite account for how they would work once broken in. I had one of those Blofelds for awhile, bought a second because the deal was too good to pass up and it was pretty much new in box. I like the knobs, love the detentless encoders.

          • diggan 7 hours ago

            > The encoder issue was fixed with a firmware update,

            No joke? I was sure it was a hardware issue, but guess I should give that a look, still have my Blofeld around here somewhere, thanks for sharing the "news" :)

            > love the detentless encoders

            I have no issues with them being detentless, makes a lot of sense. What I do have issues with, is using the smoothest material they could find for the knobs instead of something you can "grip", sometimes it just slipped between my fingers when trying to turn them, unless I make my fingers slightly humid first.

      • rjh29 6 hours ago

        Agreed. My comment doesn't apply to the 0.005% of synth owners who actually perform live :P

  • lolive 13 hours ago

    Additional note: synth emulation is also available in the Bristol Linux app, or in the [proprietary but very complete] Arturia VST.

  • ACCount37 10 hours ago

    Creating music was never more accessible than it is now.

    Conversely, the likelihood of making it big just by making some good damn music was never lower than it is now. Makes for a fine hobby though.

    • diggan 9 hours ago

      > Conversely, the likelihood of making it big just by making some good damn music was never lower than it is now.

      Is that statement backed by any facts? Otherwise it sounds like a soundbite that sounds good, but I'm not sure how true it is. Maybe what "making it big" has changed more compared to how many people make their living making music, which for me would be enough to be considered "making it big".

      • AlecSchueler 6 hours ago

        Do you believe more people per capita now make their their livings as performing musicians?

    • usrusr 8 hours ago

      How will that hobby fare against gen-AI prompt composing? Synths and samplers and sequencers were once removed from playing real instruments, softsynths and DAW twice removed and now there's genAI, thrice removed and arguably the biggest jump of them all. When softsyths appeared, real instruments weren't affected at all, but physical synths all but disappeared, just carried on by inertia, integration with real instruments and a bit of nostalgia. Will the same happen to soft synth now that there's an alternative thrice removed from real instruments?

      I believe so: in an aging softsynth community I still mingle with occasionally, everybody who is still actively involved with music seems to have either moved on to genAI, or to soft-on-Rpi for better integration with real instruments (including synths of all kinds).

      • sbarre 7 hours ago

        > How will that hobby fare against gen-AI prompt composing

        The beauty of a hobby is that you do it for yourself, not for others.

        So even in a (terrible) world where 100% of commercial music was AI-composed, someone's hobby of writing music by hand would likely remain unaffected.

      • zeknife 6 hours ago

        I assume you're not very interested in the subject if you think synthesizers aren't real instruments

      • AlecSchueler 6 hours ago

        > How will that hobby fare against gen-AI prompt composing?

        Pretty well, I believe. The joy of playing is largely the act itself, becoming one with your instrument and stepping into a world outside of time. Composition is an adjacent pastime.

      • otabdeveloper4 6 hours ago

        > physical synths all but disappeared

        Disappeared from where? In terms of units moved I'm guessing there's an order of magnitude more sold today than in the 90's or 80's.

  • m_kos 11 hours ago

    For synth heads, there is also a well-regarded Syntorial app/course. (BTW, has anyone tried their Building Blocks? There are very few online reviews.)

    • bzzzt 5 hours ago

      Building Blocks was a pack-in when I bought Syntorial in last years sale. It's technically different (web-based instead of a standalone app like Syntorial), and tries to do with music theory as a whole what Syntorial does with synthesis. Since it goes through the same 'theory, practice and create' cycle every time (eg. once for every chord type) I found it getting a bit tedious after a while.

  • Juliate 11 hours ago

    Yes! But, huge but, very huge but, you lose the affordance of the switches and the buttons and the knobs and the patch cables. And that is a terrible loss for fiddling and discovery.

    • xdfgh1112 3 hours ago

      You gain presets lol. And in the case of odyssei it has a ton of additional features including a sequencer and full effects bank!

      Experiences vary but sliding a slider on a screen is worth the benefits.

    • lolive 10 hours ago

      My path has been to work a lot in the ODDYSEi app.

      Now that I understand most of it, I am really considering buying a ARP 2600 replica.

      So yes, the switch from software to hardware comes with time. But, at least for me, the first step is cheap apps on my already-owned tablet.

    • lolive 11 hours ago

      True. But for going from zero to semi-hero, that’s definitely an option. [the huge amount of presets in software synths is really an BIG added value, so you can learn how each given sound is built]

      • Juliate 10 hours ago

        Definitely agree too. Budget is definitely not the same.

        And something like VCVRack is heaven to learn, experiment and understand what one can do with synthesis, step by step.

    • zokier 8 hours ago

      Midi controllers work plenty good with ipads

      • Juliate 6 hours ago

        Totally agree, and it's an intermediary step, but it's still not the same.

        I mean, it's terrific to have an affordable replica, especially for discovery, I'm not debating the price-point advantage (for both acquisition and maintenance), but this is not an on-par replacement.

        In an analog (less so in digital, but still somehow) synth, the controls are the instrument itself: they are in a specific place, react in a specific way, and physically part of the device that outputs the sound, and they stay there: you cannot move one without the other. The instrument has its own character. It's still more abstract than a classical instrument like the violin or the piano where the physical action alone is done and felt in real time, of course. It's significantly more incarnated than software + generic (in a good way) controllers.

        The good side of this is that after having software replicas or original synthetisers, there's room to build new exciting embodiments/physical instruments.

    • kstrauser 11 hours ago

      My first synth was a TX81Z. That one set of buttons I’ll never miss.

superb_dev 2 hours ago

I rebuilt an old midi keyboard and put a Pi inside it to run the onboard synth. I used Cardinal, a fork of VCV Rack, to define all of the synth voices

nottorp 6 hours ago

Silly layman question: where is the actual sound generation done? Because I don't see the Raspberry Pi as free of electrical noise...

(Still have memories of trying to find the usb port that didn't introduce noise in my usb creative thingy...)

  • MomsAVoxell 5 hours ago

    In the case of both Zynthian and Monome systems, both based around the raspberry Pi, there is a dedicated ADDAC circuit added to the case.

    For things like the Korg synths which use the raspberry pi, they added their own DAC's too.

rcarmo 9 hours ago

I’ve actually been building a few synths based on the Pi over the years—it’s been a great way to “get rid” of the older boards as time goes on, although since I’ve never bought a Pi 5 I suspect that time has past.

You can use the Pi 2/3/3a/Zero 2 to build things like an mt32 or DX7 emulator almost trivially, and they make for great DAWless modules.

closetkantian 9 hours ago

Recently I've been thinking about deconstructing a ThinkPad and putting the internals inside a MIDI controller. We're at the stage where VSTs/DAWs easily sound better than any synthesizer with internal sounds. But, it's a huge pain to carry a laptop and a sound card to a gig. When will someone address this?

barrenko 11 hours ago

When the word synthesizer is used, it's not meant to be a piano like thing or? For me the word is analogous to "piano keyboard" but it seems to not be so...

  • kstrauser 11 hours ago

    A synth is a device that generates sounds. They’re often (but not always!) controlled by piano-style keyboards, but so are lots of non-synth things. For example, although a piano emulator could be a synth, they’re generally not thought of that way. A sampling keyboard is not a synth: it’s playing back recorded sounds.

    Lots of synths spent their whole lives never connected to a keyboard, but might live in rack mounts and be driven by sequencers or DAWs.

  • otabdeveloper4 6 hours ago

    The OG synthesizer concept is the combination of oscillator + frequency filter + amplifier.

    As a musical instrument it is closest in function and mode of operation to the singing human voice and nothing at all like a piano.

rfl890 7 hours ago

What is the point of making hardware synths on a Pi when you could just make a VST?

  • diggan 7 hours ago

    What's the point of giving constructive feedback when you can question people's motivation instead?

    Do you think that making a VST is a realistic alternative to the linked instruments in the submission article? I'm guessing they're building hardware because they want something physical, it's pretty self-evident isn't it?

  • otabdeveloper4 6 hours ago

    For a musical instrument you want something portable and playable live, which is the opposite of what your VST contraption is.

    (Only a very tiny minority of people want to record music. Music is mostly a realtime experience.)

  • sbarre 7 hours ago

    I can't tell if this is sarcasm.

youngtaff 12 hours ago

There’s quite a few Eurorack modules that use the RP2040 too

4k93n2 12 hours ago

theres also things like the M8 tracker from Dirtywave which uses a teensy board and sounds really good for a chip of that size

  • m_kos 12 hours ago

    The m8 and the recently, heavily promoted Woovebox 2 are the Emacs/Vim of grooveboxes. They hide a vast amount of functionality behind what initially seems like an impenetrable jungle of button presses and shortcuts; a system that ultimately proves* to be highly ergonomic.

    *Based on what I read. Sadly, I don't own these devices.

    • packetlost 5 hours ago

      I own an M8 (and also, happen to be a vim user lol) and it's sorta true, but it feels a lot more natural if you're familiar with the LSDJ-style workflow. LSDJ is a DAW built for the GameBoy so was working with very constrained hardware. Both are derived from sequencer workflows, but I'm not quite sure which or where those originated.

      That being said, the M8 workflow isn't all that bad, but it's definitely less visual than most other DAWs.

  • padraigfl 7 hours ago

    Yeah I'm not an expert by any means but my understanding is the Teensy 4.1 is especially ideal for DIY synths between the number of pins available and its strengths as an audio processor.

Applejinx 9 hours ago

For some time now I've been supplying all my audio DSP plugins at airwindows.com pre-compiled on the Pi 400. (MIT open source, so it's not limited to that). The Pi version is included.

I mention this to make a point: you can't transform synths just by running some generic DSP code on a Pi and putting it in a box. Sound processing is also being transformed, and whether it's something like Hydrasynth generating poly aftertouch (but aliasing and not sounding that different from a VST) or Novation Peak/Summit receiving poly aftertouch (not generating :D ) but generating sound using custom hardware, sitting a VST on a Pi isn't going to get you a transformative synth.

Thing is, if you're able to dig into stuff like my DSP codebase that is actively under development AND plunk a VST synth onto a Pi AND do something interesting with the physical controls to direct the synth engine, that's starting to look transformative again. But just knowing about Pi isn't enough, you'll have to have a deep background in soundmaking and the ability to instrument-make in an interesting way.

If you have those things… game on. You can begin work FAR more cheaply than ever before, and that is how the Pi could be transforming synths.

I'm waiting for 24/96 audio hats to be common before I dig into this, even for stompboxes. I'm given to understand Electrosmith Daisy already has this, and that's a similar class of 'system on tiny board' that should be considered an audio Pi-like.

bartvk 12 hours ago

Typical how they first let Korg do the talking, when actually, Korg is much slower to innovate. With one line, the article mentions Tasty Chips synthesizers (who are friends of mine), but as far as I know, they were actually the first, just check their Kickstarter campaigns which go back ten years.

Note that using RPi is not all sunshine and roses. There were times that compute modules were extremely hard to get.

TomMasz 9 hours ago

I was interested in the Zynthian kit, but it's unavailable in the US right now due to Trump.

  • MomsAVoxell 4 hours ago

    It's a pity - I absolutely love my Zynthians. I have 3, they're that useful.

    Literally the Swiss army knife of audio/synth hacking.

charcircuit 13 hours ago

What if instead it ran on a macbook which you plugged the keyboard into. You could still make the software open source if you want.

  • snom380 13 hours ago

    Arturia does that, and Korg did as well (making controller keyboards specific for emulating a synth, with the software running on a Mac or PC.

    Downsides: - if the software doesn’t get updated, you’re stuck running an old OS an old Mac that supports it. - you can’t just turn on the synth and use it, you need to find a cable, connect it to the Mac, launch the software, etc

    • m_kos 11 hours ago

      What I don't quite get is why manufacturers of midi controllers (Arturia, Novation, NI, etc.), with the exception of, possibly only Korg, don't release any of their digital instruments as mobile apps. After sitting the whole day in front of my computer, the last thing I want to do is to swap VS Code for Ableton or Kontakt and spend a few more hours in the glow of my monitors.

      (I do get that if you are very serious about making music you need a proper computer set up. I am just a mere amateur hobbyist.)

      • jackvalentine 8 hours ago

        This is why I bought a teenage engineering op-1. Yes it’s overpriced, yes there are definitely better little desktop synths but I can whip this one out and just go wild without having to look at a (real) screen.

        Same reason I keep my Roland Fantom around - has everything built in to the device.

      • zokier 8 hours ago

        Both Novation and Arturia have some stuff for iPad?

sweepish 5 hours ago

If it’s based on a DAC it ain’t analogue.

“ Similarly, part of the complexity is in making an enclosure with appropriate controls and displays.”

lol