A DX7 USB Dongle(diyelectromusic.wordpress.com)
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A DX7 USB Dongle
https://diyelectromusic.wordpress.com/2023/11/22/a-dx7-usb-dongle/
48 comments
Thanks! Changed from https://hackaday.com/2023/11/24/a-yamaha-dx7-on-a-usb-dongle... above.
The sound of a DX7 not the 10 ton keyboard[1] :-) The ability to re-create these sound flavors "on the cheap" is really something. I keep wondering if someone is selling nice keyboards that one could pair with these sound modules.
[1] Keyboard not literally 10 tons, it just feels that way when lugging it to and from the van to the gig, typically about 40lbs in the case with accessories.
[1] Keyboard not literally 10 tons, it just feels that way when lugging it to and from the van to the gig, typically about 40lbs in the case with accessories.
Sure, but you'll always have some lag and the aftertouch of the DX7 might not come across in the same way. But any half decent midi keyboard should work, for instance:
https://www.thomann.de/nl/native_instruments_komplete_kontro...
They have Fatar keyboards which is more than good enough.
https://www.thomann.de/nl/native_instruments_komplete_kontro...
They have Fatar keyboards which is more than good enough.
I was thinking more like the burgeoning mechanical keyboard business for computers. If the mechanical structure was there your could provide arbitrarily low latency (some of the high end 'gamer' keyboards are sub-millesecond). Given the physical system you're modelling (Harpsichord, Piano, Etc.) all of the computation vis-a-vis the velocity can be computed while the key is moving and delivered when the key is "down", after touch on a per-board basis is easy, per key basis doable with more sensors. After touch doesn't have quite the latency requirements either. With these 25 cent M0+ 45MHz processors you could put one on every single key and 88 keys would incur like $88 cost for electronics.
For what it's worth, I've been into hardware and software synthesizers for a while and in the many many discussions I've seen around MIDI controllers and keyboards, I can't recall latency ever coming up. As far as I can tell, basically all MIDI hardware is fast enough that musicians don't seem to notice or complain.
If the MIDI controller is connected via USB and is polled at 1 ms, you have only about that amount of lag. This is not something most people can even notice.
Also, consider that even playing an acoustic piano has quite some lag: your brain has to send a signal to the muscles in your hand, which have to contract, which presses the key which takes some time to travel down, the hammers needs some time to travel to the strings, then the sound takes some time to travel to your ear. All this adds up to many milliseconds of delay. A musician already compensates for all that by starting the hand motions earlier to compensate for that lag. As long as it is not too large and if it is consistent, a few milliseconds extra does not matter.
Also, consider that even playing an acoustic piano has quite some lag: your brain has to send a signal to the muscles in your hand, which have to contract, which presses the key which takes some time to travel down, the hammers needs some time to travel to the strings, then the sound takes some time to travel to your ear. All this adds up to many milliseconds of delay. A musician already compensates for all that by starting the hand motions earlier to compensate for that lag. As long as it is not too large and if it is consistent, a few milliseconds extra does not matter.
So 3 milliseconds is about how long it takes sound to travel 1 meter.
So it's like the difference between how far a pianist sits from the strings in an upright vs a grand piano. Or the guitar player taking a couple of steps away from their amp. Or the difference between a drummer hitting the snare or their crash cymbal.
One of my local theatres says the stage is 19m wide, so an orchestra playing there is probably 50 ms apart for onmstruments playing on opposite sides of the stage.
Hell, you've got most of a millisecond of "lag" between your left and right ears for sounds coming from the side.
So it's like the difference between how far a pianist sits from the strings in an upright vs a grand piano. Or the guitar player taking a couple of steps away from their amp. Or the difference between a drummer hitting the snare or their crash cymbal.
One of my local theatres says the stage is 19m wide, so an orchestra playing there is probably 50 ms apart for onmstruments playing on opposite sides of the stage.
Hell, you've got most of a millisecond of "lag" between your left and right ears for sounds coming from the side.
Submillisecond differences for audio > 1 KHz tend to show up as phase differences (after all: 1 ms period == 1 KHz) which allow you to figure out where something is located.
The difference between your right and your left ear is indeed on that order and so phase change really starts at roughly that frequency and below that it all just blends together. That's why bass speakers aren't directional and you can have a single big woofer in the middle and it won't make much of a difference in what the sound is like in the stereo image. But if you collapse your high or mid then suddenly all sense of position is gone.
So anything below 1 ms is negligible, as long as it isn't so long that it starts to confuse you. Not rare in church organs, where the lag can be so long that you wonder if you've depressed the key at all, you get used to it after a while but it is a very weird experience.
It's interesting that you can spot an out-of-phase wired woofer fairly easily by just moving around the room, if the sound of the bases cancels out in the middle that usually a good sign that either woofer has its polarity reversed from what it should be. The sound will be 'hollow' (I have no better term for it, that's what it sounds like to me).
The difference between your right and your left ear is indeed on that order and so phase change really starts at roughly that frequency and below that it all just blends together. That's why bass speakers aren't directional and you can have a single big woofer in the middle and it won't make much of a difference in what the sound is like in the stereo image. But if you collapse your high or mid then suddenly all sense of position is gone.
So anything below 1 ms is negligible, as long as it isn't so long that it starts to confuse you. Not rare in church organs, where the lag can be so long that you wonder if you've depressed the key at all, you get used to it after a while but it is a very weird experience.
It's interesting that you can spot an out-of-phase wired woofer fairly easily by just moving around the room, if the sound of the bases cancels out in the middle that usually a good sign that either woofer has its polarity reversed from what it should be. The sound will be 'hollow' (I have no better term for it, that's what it sounds like to me).
My suspicion is that nobody could tell the difference between sub milliseconds, and several or even tens of milliseconds so long as the latency in both channels is the same. The stereo imaging isn't going 5to change if the L/R signal transient is at 0.000/0.0001ms, compared to 3.000/3.0001ms. The phase difference is the same.
(Surely that church organ delay is an artefact of the pneumatics, not the speed of sound travel time between the player and the various pipes?)
(Surely that church organ delay is an artefact of the pneumatics, not the speed of sound travel time between the player and the various pipes?)
that Church organ delay is very much an artefact of the speed of sound travel time: the pipes sound half the cathedral away from the organist. In some churches this is made even worse because there is a conduit across the top of the vaulted space injecting sound into the other end directly, so then you get both a direct wave and a diminished one with a massive delay.
Super confusing, the best way to deal with it is to just put on headphones and only listen to the direct sound.
Super confusing, the best way to deal with it is to just put on headphones and only listen to the direct sound.
> The sound will be 'hollow' (I have no better term for it, that's what it sounds like to me).
"Hollow" is a good description. It's the weird missing fundamental [1] sound you can get from a high pass filter.
[1]: https://en.wikipedia.org/wiki/Missing_fundamental
"Hollow" is a good description. It's the weird missing fundamental [1] sound you can get from a high pass filter.
[1]: https://en.wikipedia.org/wiki/Missing_fundamental
Ah interesting, thank you. I know about the missing fundamental because I run into that when tuning the low end of the piano and when trying to re-create the lowest notes on the piano from audio files. But I never made the connection to the canceled out bass notes but it is obviously the exact same thing.
Another metric to think about if you care about rhythm. In a 4/4 beat at 120 BPM with 50% swing (i.e. straight 16th notes with no swing), sixteenth notes are 125ms apart.
Each percent of swing is 2.5ms. So if you increase to 51% swing, it's 127.5ms and 122.5ms between successive pairs of 26th notes. 55% swing (which is very distinct from 50% to my ears) is 137.5ms and 112.5ms.
Each percent of swing is 2.5ms. So if you increase to 51% swing, it's 127.5ms and 122.5ms between successive pairs of 26th notes. 55% swing (which is very distinct from 50% to my ears) is 137.5ms and 112.5ms.
Just wait until midi 2.0 catches on! /sarcasm
I once recorded an album and had to deal with latency issues. This was way back using an IBM Aptiva and Magix music software (because it was pretty affordable). I spent so much time trying to figure out why my vocals were behind the beat. Eventually I worked out the correction factor to be 1.002433. So that's what I named the album!
Since then, I'm glad that latency problems are much less of a problem. Nothing worse than a little latency if you have ears like Donald Fagan. :-)
I once recorded an album and had to deal with latency issues. This was way back using an IBM Aptiva and Magix music software (because it was pretty affordable). I spent so much time trying to figure out why my vocals were behind the beat. Eventually I worked out the correction factor to be 1.002433. So that's what I named the album!
Since then, I'm glad that latency problems are much less of a problem. Nothing worse than a little latency if you have ears like Donald Fagan. :-)
I wouldn't be able to build a substitute for a half decent brand-new manufactured keyboard for $88 if I got the parts for free. I've build some interesting musical keyboards but mostly because they had geometries that were non-standard and I'm still toying with the idea of making a complete action from scratch. But that's 'madman' territory, just as a challenge, not for cost savings.
Sorry I wasn't clear, I was think just the electronics at $1 per key. The action for the keyboard would cost more than that. In my alternate life I find a broken/disused KX-88 and rebuild its keyboard :-)
Shall I keep an eye out?
I repair DX-7's to keep them alive (usually three broken ones yield about two good ones and some spare bits), I can look for KX-88's while looking for DX-7s if you want.
I repair DX-7's to keep them alive (usually three broken ones yield about two good ones and some spare bits), I can look for KX-88's while looking for DX-7s if you want.
I periodically search Craigslist for them and I've asked the local gear reseller (Starving Musician) to be on the eye out for a "dead" one. I seriously doubt having one shipped would be cost effective :-). There is a $50 one on Ebay in Illinois for local pickup.
That will be hard to beat :)
Go grab it then! For that kind of money you really can't go wrong.
Go grab it then! For that kind of money you really can't go wrong.
Hah hah! I had to lug around a Rhodes suitcase, a B3, and a Leslie. My DX7 in an anvil case weren’t nothing.
MPK Mini is all you need, they're like 80 bucks
If I understood right, it's a DX7 synth running on bare metal on a Raspberry Pi, and the news is that they added the hardware / software to use it as a (device-side) USB device.
Which is very cool, but "USB Dongle" confused me a bit.
Which is very cool, but "USB Dongle" confused me a bit.
The article uses a raspberry pi zero to be pendantic, but it seems to support any pi.
I was researching using the Pi Pico for FM synthesis recently, it turns out it isn't powerful enough to do more than about 3 voices of 6-operator FM due to having no fpu.
Here's the hardware docs page:
https://github.com/probonopd/MiniDexed/wiki/Hardware
I was researching using the Pi Pico for FM synthesis recently, it turns out it isn't powerful enough to do more than about 3 voices of 6-operator FM due to having no fpu.
Here's the hardware docs page:
https://github.com/probonopd/MiniDexed/wiki/Hardware
It'll look good when the audio out is routed in to the USB audio interface to come back to the computer for recording!
If you're in Europe and want an actual DX7 I still have one that has been doing nothing for the last 12 months because I'm too busy with the piano. But Dexed is pretty much bit-for-bit perfect so if nostalgia isn't your thing you're better (and cheaper) off with Dexed.
How much are you selling your DX7 for?
Hm, email maybe? [email protected]
I'm in NL and sending it in the mail isn't an option.
I'm in NL and sending it in the mail isn't an option.
Has Dexed improved since both OGS and EGS were reverse engineered?
It is a nice implementation of 6op FM synthesis compatible with DX SysEx dumps, but _i_ wouln't call it bit-perfect.
Can you name a specific thing that doesn't work the way it should?
Dexed is a really good implementation of the DX7, and there are thousands of "cartridges" to be found online packed with presets for it.
I believe that these days Dexed is the preferred environment for people who make presets that they're subsequently going to play on an actual DX7, it's that good.
> it's that good.
For what it's worth, being "that good" is relatively easy for a DX7 compared to other synthesizers since it's a purely digital design and the algorithms (in the software, not FM sense) are pretty straightforward. It's not like emulating, say, an Ensoniq SQ-80, where you have to emulate analog filters which always involves a level of compromise and approximation.
For what it's worth, being "that good" is relatively easy for a DX7 compared to other synthesizers since it's a purely digital design and the algorithms (in the software, not FM sense) are pretty straightforward. It's not like emulating, say, an Ensoniq SQ-80, where you have to emulate analog filters which always involves a level of compromise and approximation.
very smart and simple little machine. I recall thing on HN a while back - impressive stuff https://www.righto.com/2021/11/reverse-engineering-yamaha-dx...
I do this. I use Dexed as a patch editor for my DX7. It's fantastic. I wish I had editors this good for the rest of my synths!
Don’t forget “This DX7 Cartridge Does Not Exist”:
https://news.ycombinator.com/item?id=23373730
https://news.ycombinator.com/item?id=23373730
...a lot of those presets are 'dice driven', it seems to me. Press a dicembre random settings, save: give it a name.
Synth1 on the other hand....
I’d love to see one of these dexed-based devices designed with knobs to control the operators and envelopes. FM can create some gnarly sounds.
There are a few VST plugins (thinking of Plogue’s OPS7 and Reason’s Algorithm in particular) that can do this and I think you have a lot of control with the Korg Opsix but I don’t know if a Dexed/miniDexed design that does that.
There are a few VST plugins (thinking of Plogue’s OPS7 and Reason’s Algorithm in particular) that can do this and I think you have a lot of control with the Korg Opsix but I don’t know if a Dexed/miniDexed design that does that.
Little fun fact, but the Korg Opsix is also a raspberry pi powered FM synthesizer.
https://www.raspberrypi.com/success-stories/korg-synthesizer...
https://www.raspberrypi.com/success-stories/korg-synthesizer...
I have an original dx7 and rx5 drum machine.
I think the RX5 is an awesome drum machine. Made me see the value in old flagship instruments. The design logic is robust and nothing in the workflow lags.
I have a Pharmasonic ROM cartridge for mine.
I have a Pharmasonic ROM cartridge for mine.
I also had a Roland boutique d-50 clone which was awesome, but I sold it which i regret.
Some things I buy more than once. I buy it. Don’t use it. Sell it.
Then find myself with the same problem and go through the same research and come to the same conclusion.
The net costs are just rent in my mind. Or the difference between getting a great deal and paying more than I might have. Or just money I spent on my hobby.
Then find myself with the same problem and go through the same research and come to the same conclusion.
The net costs are just rent in my mind. Or the difference between getting a great deal and paying more than I might have. Or just money I spent on my hobby.
I guess that’s one way to solve the tiny screen problem.
I think I'll stick with DX7 V, but this is neat.
https://diyelectromusic.wordpress.com/2023/11/22/a-dx7-usb-d...