Converting a Guitar Effects Pedal to Output MIDI | Hacker News Reader

Converting a Guitar Effects Pedal to Output MIDI

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Anybody come across a pedal/switch that would output sustain MIDI signal? Or would Arduino's MIDIUSB work for a DIY version? I have a couple of keyboards (Roli Seaboard block and Roland JD-Xi) without sustain pedal inputs and would like to use a sustain pedal with them

edit: found one - https://webaudiotech.com/2017/02/20/a-piano-sustain-pedal-to...

I remember being in a guitar store and hearing a pedal that converted a guitar, chords and all, into MIDI piano samples of each note being played. Or that's what it sounded like. It blew my mind! Does anyone know what pedal this was?

AFAIK the only systems that can reliably do this including chords are guitar synths, which require special pickups that capture the vibration of each string independantly. Some guitars are made with these special pickups already integrated, so at first glance it might look like an ordinary guitar + pedal arrangement.

For example: https://www.roland.com/global/products/gc-1/

Not piano, but could it be the EHX B9? It's an organ emulator for guitars. Not really doing the full pitch/chord detection you would need for generic MIDI output (I believe it's vocoder based, but I might be wrong).

I bet it was the Roland setup. I forget the model, but it uses individual pickups for each string and some huge 9 conductor cable to go to a decoding box. I still have one somewhere. The latency was terrible, and more than one note at a time was a gamble, but it was fun for string sounds with a slow attack. Some guitars in the 90s even had the setup built in.

To go back even further, check ot the original, the VOX Guitar Organ. Lots of vids on youtube.

Yeah sounds like the Roland GK-3.

Expensive, finicky. But it did convert to MIDI for sound purposes. Enough so that Fender even sold a model with the Roland pickup built in.

Source: 20+ years with guitar and way too nerdy with MIDI and stuff over the years

With more modern tech it should be possible to make quite a small decoder that fits into the body cavity, then shoots out the MIDI via Bluetooth LE. (And fix the latency issue to boot.)

Do you know if anyone has attempted such a feat?

Am embedded electronics designer, for context.

I think this would be either EHX Key9 (which actually doesn't have MIDI) https://www.youtube.com/watch?v=av4X84lChEE or Roland GR55 https://youtu.be/YqKZYUExYCs (which actually can be used for other sounds than piano), or possibly some older Roland device.

Maybe it's the Electro Harmonix KEY9. I own this one and you can play single notes and chords which sound like an electric piano / wurlitzer etc.

> I remember being in a guitar store and hearing a pedal that converted a guitar, chords and all, into MIDI piano samples

I remember the same experience (in like 1989).

As others have said, it was probably a Roland GR-series unit connected to a guitar with a hexaphonic pickup.

If you're a computer-based musician, an excellent option is Jam Origin's Midi Guitar 2. It's a pure software solution that accepts any guitar as an input. It works polyphonically, has low latency and tracks the notes with remarkable accuracy.

https://www.jamorigin.com/

Aside from Roland technology, Graph Tech makes the Ghost system which - depending on the model - can provide MIDI or acoustic piezo individual pickups embedded in the guitar saddle. Godin does a lot with Ghost saddles for their MIDI guitars. The Ghost system is the only MIDI pickup solution that offers an invisible look to it. Fishman's TriplePlay also offers this functionality, but it isn't a built-in interface.

As digital pedals get better I'm sure we'll eventually be able to get away without a MIDI pickup, but I'd bet overtones inside some chords could really confuse a system which is effectively trying to decode frequencies in real time to identify the fundamental. However, with that said, Digitech is getting really close with this ability in their long-running Whammy pedals to transpose entire chords as well as individual notes.

Awesome! The market is really short on good MIDI pedals. Most pedals are in the €150 - €500 range and they have no versatility. You have to buy different pedals to be able to connect it to different gear. When you compare them to MIDI controllers from of the likes of Akai and Korg it's just depressing. They have velocity sensitive buttons, wireless-, USB-, standard MIDI and beautiful hardware for less than $80.

Someone go make a Kickstarter!

http://moddevices.com/mod-duo

There's this kickstarted product that has a midi in (not out), but it's pretty pricey. It's open source and extremely versatile / hackable though.

Honorable mention: The Howton Owl which is cheaper and you can program it in C / C++, but it's audio only (no MIDI).

Edit: Actually it turns out the Owl can use its USB port as a MIDI port of some sort(s), and also there's a UART that can theoretically be used for MIDI but you'd have to work out how to do that yourself.

Damnit!

Those are some nice projects and I like that you can plug your instruments and microphone directly into the pedal. Now my requirements list for the ultimate controller pedal has grown. ;-)

Start with something like the Behringer FCB1010. Add some programmability and get rid of a few unnecessary cables similar to the mods that are available on http://www.fcb1010.eu. Switch to USB-MIDI and add two TRS combo jacks with so I can plug in my microphone and my guitar. The pedal should double as a audio interface, a MIDI controller, be powered over USB but be capable of powering my tablet over USB when hooked up to 9V.

As I write this I realize that what I'm looking for is pretty much a Guitarjack Stage https://www.sonomawireworks.com/guitarjackstage but with more footswitches, less knobs and two built-in expression pedals.

You might be interested in axoloti: http://www.axoloti.com/

Stereo input/output, midi in/out, and it can function as a USB host to class-compliant usb/midi devices. Programmable using a puredata-esque visual programming editor, but you can also extend it with C.

Okay, I will be the guy.

MIDI is dead.

The latency, is simply not musical. I have worked with midi since the early 90s. Its a low baud serial connection. Play 5 notes at once? Nope, its now a really fast appregio. Got a nicer keyboard that sends velocity, aftertouch and control commands? Even more quickly flooded.

The problem is, its such a widely implemented standard, and yet there are few, if any, out of the box midi-on-chip solutions that make sense.

If someone produced a new standard, focusing on latency, and somehow made a midi failover/compatibility mode. Midi2 if you will... that could be easily implemented by device makers. The whole world would get better music.

Correct me if I'm wrong, but these days everyone usually sends MIDI over USB. It doesn't have any of the problems you described, every computer has USB ports in some form or another. Every operating system has default drivers for these devices, so they usually work out of the box. Yes, MIDI as a hardware standard is dying. But why should we care when we have something more universal that replaces it?

Sure, but we need the physical layer. Somewhere between the 5 +1 pin DIN and the logic.

We need a standard to replace it becaue music should not nessitate the use of a seprate computer to communicate.

Beyond that I could dive in to the MIDI signaling standard itself, and why it is outdated for sending most types of relevant digital information using todays synthesis and controller technology.

USB isn't optoisolated. This is its killer flaw as a replacement MIDI transport.

It can be, see https://www.adafruit.com/product/2107

Surprised the high-end gear doesn't built it in!

True, but to put things in proportion: I'll be delighted the day I can have a soft synth with a latency as low as MIDI.

Well there's MIDI the electronic standard, and MIDI the musical serialization format. The former is moribund, the latter definitely isn't.

Fiar enough. I was looking at it as a whole system. Because if I connect my keyboard or pedal, it isnt just the data format. But I am mostly talking about the physical standard in my post. Its just infuriating I still suffer the same or worse delay when using hardware as I did in the 80s.

"MIDI is dead.

The latency, is simply not musical. I have worked with midi since the early 90s. Its a low baud serial connection. Play 5 notes at once? Nope, its now a really fast appregio."

I suspect that's wholly upon your equipment. I've got an old 486 with an AWE32 on it. Never once in my life have I encountered the problems you describe and my keyboard was a DIN5 connected Korg.

"Got a nicer keyboard that sends velocity, aftertouch and control commands? Even more quickly flooded."

Let me guess, you were using the game port on the back of your sound card instead of a sound card with a dedicated MIDI input/output?

You have system configuration problems.

What you are describing would stop the entire music industry from functioning.

I would agree that you probably can't literally hear the delay among five note-on messages if nothing else is happening. That'd be about .5ms which is pretty insignificant.

But it does become a real thing if you're sending a lot more than that around, like pitch, velocity etc.

It doesn't affect the music industry much because MIDI is overwhelmingly a software standard not a hardware standard these days, so the low baud rate doesn't apply.

Edit: Wait, no, 5ms which is heading towards noticability but not there yet.

Each midi note on and off always sends both pitch and velocity.

The first byte tells you it is a note on or note off and the MIDI channel, the second byte tells you the pitch and the third byte tells you the velocity.

I should have said pitch bend and aftertouch.

Open Sound Control is effectively MIDI2 - it ameliorates all of the obvious shortcomings of the MIDI standard. It isn't hugely popular, because MIDI is good enough for 99% of users 99% of the time.

http://opensoundcontrol.org/introduction-osc https://en.wikipedia.org/wiki/Open_Sound_Control

MIDI MPE goes some way to addressing some of these problems.

https://www.midi.org/articles/midi-polyphonic-expression-mpe

Keith McMillen Instruments make a fantastic foot controller based on "smart fabric" technology. Each of the footswitches can detect pressure in three axes, so it can be used for some very sophisticated expressive playing.

https://www.keithmcmillen.com/products/softstep/

I bet you could also use Dictation Commands if you're recording on a Mac, to press the record button by talking.

Depending on what you’re activating via the pedal, the timing is very important (e.g. starting/stopping a loop). Voice wouldn’t be a good fit in that case.

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