[HN Gopher] I built a amp+cab+effects simulator for guitar on a ...
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I built a amp+cab+effects simulator for guitar on a Raspberry Pi 4B
Author : fivedogit
Score : 88 points
Date : 2020-04-19 19:17 UTC (3 hours ago)
(HTM) web link (thingamagig.com)
(TXT) w3m dump (thingamagig.com)
| weej wrote:
| Thanks for sharing. This is great. I appreciate the additional
| insight in the comments on the software behind it for the guitar
| effects & tones. Kudos on the experimentation and iterations to
| meet your needs. Wish I would have seen this for a potential DIY
| project before I went in on purchasing the SPARK amp for at home
| practices and FXs.
| fivedogit wrote:
| I became aware of Spark a couple of weeks ago. On the one hand,
| I was irritated that someone else was on the same "voice-
| controlled guitar playing" thread as me, but then (a) it's
| validating and (b) they're not really going the same place I
| am.
|
| Thingamagig understands the underlying composition which means
| it can automate tones, loopers, lights, cameras, etc. That need
| was the genesis of this project and that's where its going.
| Everybody else (including Spark, Fender Play) seems to think
| the playalong is the end goal, which is why they short circuit
| the hard work of building the composition library by
| integrating Spotify or whatever.
|
| Maybe they're right. Maybe I'm right. Maybe we're both right.
| We'll see, I guess.
| StavrosK wrote:
| This looks impressive, but I'm most curious about the Alexa
| integration. How do you do that without having to say "ask <app
| name> to <x>" every time?
| ricardobeat wrote:
| In the video at the end of the page that is exactly how it
| works: 'Alexa, ask Nexus to open Back in Black by AC/DC'.
| StavrosK wrote:
| He does say "Alexa, give me some metal EQ" and similar things
| multiple times.
| fivedogit wrote:
| He's making a subtle point here. There's
|
| "do x"
|
| vs
|
| "Alexa, do x"
|
| vs
|
| "Alexa, ask AppName to do x"
|
| The first is when the skill does a thing and then immediately
| starts listening again. The blue bar is already there and you
| don't need to say "Alexa".
|
| The second is when the skill is still open but not currently
| listening. Takes a bit of hackery to keep the skill from
| constantly closing, namely, long-running APL commands.
|
| The third is when the skill is closed and you're trying to
| get it to do something. I call this "deep launching" but it
| almost never works. Amazon has built an amazing system here,
| but the Alexa system needs work on recognizing skill names
| for deep launching.
| TylerE wrote:
| It isn't impressive at all. It's a toy completely unsuited to
| performance. The fact that he brags about "no knobs, no
| switch's" shows how he completely fails to understand the
| market.
|
| This is top class /r/shittykickstarters (and do t be fooled,
| this entire post exists just to shill a kickstarter)
|
| There are plenty of mature, established modeling solutions on
| the market.
| hombre_fatal wrote:
| Yikes.
|
| There's no need to try to convince other people that this
| shouldn't impress them. That's usually a sign that you should
| just put the keyboard down and continue scrolling.
| TylerE wrote:
| Is this a discussion site anymore? Or just a circle of
| mindless yes men?
| ricardobeat wrote:
| It is clearly for practice / home use and not for live
| performance. The main value seems to be the automation for
| switching tones based on song presets.
|
| This is also the focus in one of the mainstream modelling
| apps, ToneBridge, except it doesn't play along with tabs, so
| there is clearly a market for it.
| TylerE wrote:
| All of the existing modelers support toggling based on midi
| commands
| fivedogit wrote:
| Why the hate?
|
| Do you know of any modeling solution where you can pick up
| your guitar and play without your hands ever leaving the
| guitar?
|
| Do you know of any modeling solution that will automatically
| change your guitar tones during playback?
|
| And automate your loopers?
|
| And scroll lyrics and chords in perfect time?
|
| And (eventually) automate your vocal effects, lights, fog
| machines, drone cameras and dancing baby Groot?
|
| For < $150?
|
| Thingamagig _understands the underlying composition_ which is
| a critical component of advanced automation. No other
| solution on the market does this. If it did, I would have
| bought it and been done with it.
| blackguardx wrote:
| Launching products is super hard I wish you luck. Getting
| detractors means you are doing something that at least
| garners a reaction from people. If there are negative
| reactions, there will also be positive ones.
| TylerE wrote:
| You can all that with a helix or axed if you're going to
| mindlessly slave everything to a master track. All
| straightforward midi.
|
| Except those all have pedalboards so you can do it all with
| your feet while playing if you are actually creating
| anything.
|
| I'm still confused why you think all this total automation
| is a good thing. It's like selling a sewing machine that
| only works with premade patterns.
| throwawaybcporn wrote:
| You didn't read it. He did exactly what you're suggesting
| in the first iteration: Helix + MIDI controllers. Then he
| explained why it sucked.
|
| I mean, have your own opinion and all but if you don't
| read, then it's not as valid.
| fivedogit wrote:
| Yeah good question. Alexa skills don't want to be long-lived so
| you have to force them to stay open so you're not constantly
| saying "Alexa ask <app name> to <x>" which, by the way, hardly
| ever works.
|
| With a video skill like this, I can submit APL documents and
| then long-running commands to make it keep "doing something"
| throughout the playback. There is a limit to how long you can
| command it to "delay" but I think it's more than 5 minutes or
| something.
|
| I haven't tried it, but for non-video skills I've read that you
| can play silent audio for a period of time to keep the skill
| open.
|
| Janky, for sure.
| yummypaint wrote:
| People interested in trying out this kind of thing should also
| check out vcvrack. Its a free fully featured modular synthesizer
| system, also very easy to set up. It should be possible to run it
| on a pi, though i havent tried that personally. It also has
| excelent midi integration, so one could try to reproduce some of
| the hands free control with a program that does voice recognition
| and supports a virtual midi interface.
| [deleted]
| m0zg wrote:
| For comparison, here's what the current very best in this field
| looks like: https://www.fractalaudio.com/iii/
|
| $2K (and an absolute steal at this price), high end DSPs, high
| end multichannel ADCs/DACs. Thankfully, lots of knobs and
| buttons, and no Alexa of any kind. Sounds amazing. I have one.
| ricardobeat wrote:
| Awesome project! I was really hoping to read about the amp/cab
| simulator and effects running on the Rasperry Pi as the title
| mentions, but the software side is entirely missing from the
| story.
|
| Note that from a cursory look at the links, there hasn't been
| updates since 2018, and the KS project never launched.
| fivedogit wrote:
| Sorry if it was short on software details.
|
| It's realtime raspbian. Headless ardour (lua implementation). A
| mix of guitarix and other amp sims. Proprietary cab sim IRs.
| Various other effects packages like rkr, ardour-native plugins.
|
| Person speaks to alexa, alexa calls a series of lambdas
| (basically the not-yet-public API), and sends MQTT messages to
| the device which is tied to the user's Thingamagig account
| which is linked to their Alexa account.
|
| https://github.com/raspberrypi/linux/tree/rpi-4.19.y-rt
|
| Let me know if you have any other questions.
| donquichotte wrote:
| Looks like he used Ardour [1] and Guitarix [2].
|
| I am curious about the latency of this setup, having used jack
| and Ardour in the past for recording. I would be very surprised
| if this rig yields a latency below a couple dozen milliseconds,
| which, at least for me, is absolutely unbearable when playing
| guitar.
|
| Even with a dedicated DSP, effects processors in the early
| 2000's (like the otherwise excellent Vox TonelabSE) greatly
| struggled with latency issues.
|
| [1] https://ardour.org/
|
| [2] https://guitarix.org/
| fivedogit wrote:
| I was able to get 48000/256/3 working.
| willis936 wrote:
| Thanks for this. DSPs that accurately simulate hardware are
| not as trivial as one might initially think. I've done some
| thinking on this front, and the DSP based approaches that
| simulate hardware are likely making many shortcuts. Take a
| zener limiter circuit for example. You could just rail
| samples with an amplitude comparison, but that's a bad sound.
| So what I think most limiter DSPs do is apply a shaping
| filter to that. It's an approximation, but not really
| capturing the characterization of the circuit. The simplest
| way to get an accurate response is with SPICE simulation. I'd
| love to see a DSP that specialized in realtime SPICE
| simulation. Failing that, you have to sit down and do the
| math for each circuit yourself to establish the relationships
| between component values and signals, then code that into
| your DSP. It's not an unreasonably large amount of work, but
| judging from the people I think are selling audio software, I
| would be shocked if anyone is actually doing that.
| immy wrote:
| "please visit our kickstarter campaign launching Tuesday April
| 21st, 2020"
| zachrose wrote:
| I wonder if it would be possible to build a six-item menu
| selector that worked by picking up when you tap a string. This
| would get in the way of alternating between selecting an amp and
| trying that amp, but maybe there's some way to detect when a
| string has been tapped from behind the bridge?
| jkincaid wrote:
| This is really interesting -- thank you for building it. It seems
| some of the comments here are living up to HN's reputation. May
| that prove to be a good omen, as it has been in the past.
|
| The main thing I'm wondering is whether there's a way to record
| with this (so here's my wishlist). Often I'll be practicing along
| to another song, or just noodling around, and I'll really wish I
| had recorded what I just played. Would be amazing if I could say,
| "Alexa, record that", or "Alexa, record the last 90 seconds".
|
| Similarly: "Alexa, record this." (and then after X minutes if I
| forget to stop the recording / no input is detected Alexa asks if
| I still want to be recording).
|
| "Alexa play a metronome at 80 bpm and record this". "Alexa, play
| the last track and record a new track" (gotta make this very
| clear so as not to confuse overwriting the original vs recording
| additional layers). Sync the recording folder w/ Dropbox so it's
| ready for my DAW. Save two streams: one clean of the raw guitar
| (so I can tweak to my heart's delight later), one with the
| applied effects.
|
| I'm curious to dig into the tones more; a lot of apps are goodish
| but don't quite get it right. S-Gear is the best plugin I've
| found. Also, I'm a huge fan of the amPlug 2 line from Vox. $40
| for really impressive tones via a battery powered gadget as big
| as a few matchboxes. Sounds great hooked up to speakers and good
| enough to use in recording. But they don't give you a lot of
| options in terms of effects.
|
| Great project! Hope the above is useful -- I'll be following
| along!
| williesleg wrote:
| I'll put money on this never getting shipped.
| zwp wrote:
| Great article, I wish I'd seen the mid-project posting to HN. I
| was skeptical about the Alexa integration but that seems to work
| well.
|
| > ludicrously difficult to set up. Laptop + low-latency Linux +
| Ardour + QLC+...
|
| This resonates [sorry] with me. Linux sound today seems painfully
| reminiscent of Linux X-Windows 20 years ago. There's a lot of
| painful voodoo, competing control systems and legions of mostly
| out-dated forum threads of dead-ends, anecdotal advice,
| misinformation. I'm hoping that the next Ubuntu Studio will Just
| Work on the laptop that I have put aside for it and that I won't
| have to waste more time in the Pulse/Alsa/Jack soup.
|
| I was aware of Guitarix but have not yet played with it. My
| youngest is learning electric and we've got to the point where we
| can play together, with me pounding out the bass line on an old
| classical we had lying around(!). That is a blast but I wasn't
| really intending to become a bassist. If I were to pick up an
| electric guitar to fool around on, can Guitarix drop me down an
| octave and make me a pretend bass player? (I had a quick poke
| around the Guitarix wiki, couldn't see anything). There must be
| DAW processing plugins to do this, but I'd really like to be
| live. Are there other solutions? (apart from buying more
| instruments I mean...).
|
| Oh, and I love this:
|
| > So I bought a 3D printer and became a CAD guy, I guess
|
| "I had a hard problem to solve... so I... casually nuked it" :)
| rhinoceraptor wrote:
| It's a hardware solution, but digitech make a drop tuning
| pedal.
| zwp wrote:
| That would definitely work (and we could also use it in
| "Cobain emulation mode"!). Thanks for the tip.
| fivedogit wrote:
| Guitarix is really, really impressive and I'm eternally
| grateful, but it is raw. It takes a lot of work to get it to
| sound the way you want and is inconsistent from sim to sim.
| However, by having control over the hardware and the sessions
| (i.e. presets, basically) and totally bypassing the Guitarix
| GUI, I was able to make it work for this project.
|
| BTW, I'm not using any of guitarix's cab sims. Instead I
| purchased a commercial license to professionally-shot
| proprietary cab simulation IRs which make all the difference in
| terms of tone quality. That metal portion of the demo is all
| about the cab sims.
| grawprog wrote:
| >There's a lot of painful voodoo, competing control systems and
| legions of mostly out-dated forum threads of dead-ends,
| anecdotal advice, misinformation. I'm hoping that the next
| Ubuntu Studio will Just Work on the laptop that I have put
| aside for it and that I won't have to waste more time in the
| Pulse/Alsa/Jack soup.
|
| I've had a lot of success using kxstudio
|
| https://kx.studio/
|
| Along with cadence to manage Jack and alsa and Catia/Claudia
| for managing studios and ladish sessions.
|
| It can be installed on top of an existing Ubuntu based system
| without much trouble and after setting it up it works
| flawlessly for me. I've been using this setup for a few years
| now.
|
| >legions of mostly out-dated forum threads of dead-ends,
| anecdotal advice, misinformation
|
| I completely agree with this. Any guide that still recommends
| qjackctl or manually fucking around with alsa and midi bridges
| should be completely disregarded. There's zero reason to need
| to do this any more and there hasn't been for at least half a
| decade now.
|
| It's really too bad, honestly the flexibility offered by Jack
| and the huge range of audio software on linux allows for
| workflows I'd never been able to do on windows. It's pretty
| much the entire modular linux philosophy applied to making
| music and it's closest i've come to the same kind of workflow
| you get with hardware equipment.
|
| Just fiddling around with different plugin routings can give
| you some pretty cool sounds that can be patched into any Jack
| aware software you have.
| aidos wrote:
| Does anyone have a good guide to understanding the Linux
| audio ecosystem?
|
| I know Linux fairly well from a server standpoint, but I
| tried to do some audio stuff recently and couldn't make head
| nor tail of it.
| spacechild1 wrote:
| What's the problem with qjackctl? What do you recommend
| instead?
| sbr464 wrote:
| Check out Bela also for low latency audio.
|
| https://bela.io/
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