Someone on Facebook asked me to build this OB-SX editor for a synth fitted with a MagicBox MIDI interface. He currently uses an iPad editor supplied with the device but wanted something more physical and immediate and I came up with this. I started it yesterday afternoon after I’d finished the aftertouch stuff on my other synth project and completed the hardware this afternoon. It has a Teensy 4.1 under the board controlling things.
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Just tell me…
How many hours are there in a day in Ukraine ?
Around here we have only 24…
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We have 24 here too and I had to fit going to dinner with the wife, shopping this morning and repairing the basement sink in with all of this.
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thats good you stay busy and not dwell on the negative shit going on over there , that could get real depressing . stay safe and keep motivating us to get off are asses and get stuff done .
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@craigyb , you appear to have a superhuman understanding and also a ridiculously high rate of production.
Thank you.
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Not really, I’m like a dog with a bone, I just keep going.
My understanding of stuff is very very low compared to a lot of guys, I have no training in electronics, certainly non in analogue design. I’m just gluing stuff together and learning as I go. If it doesn’t work, try something else. Although I’ve been in computing for over 40 years I think I blagged most of that.
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Any hardware MIDI controller can be used with the magicBox, but I recommend a MIDI controller with encoders instead of potentiometers so you can edit your sounds, which is impossible with potentiometers. Controllers with potentiometers require each sound to be recreated, which is quite cumbersome.
My controller employs a pickup method where the control does not change the setting until it passes the value of the program. Also my controller stores all the patches, it is in charge so when a preset is selected it sends the values of the sound to the magic box. It is loaded with the 56 presets and the user’s 56 patches before I sent it to them, they are stored on SD card.
I was going to use the feedback method, but without a MagicBox or an OB-SX to hand that was difficult to test.
As I’ve developed this without access to a MagicBox or an OB-SX I think I’ve tried to cover as many bases as possible but the user will test when he receives it and report back.
I tried my best to cover all the options including the strange way of the reversed the resonance control to 127-0 min to max, also the switches being on different midi channels which is really not needed except to prevent others from making an editor.
I think we did speak about this by email if you are Rolf the designer of the Magicbox
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Hi there, would it be possible to get the pcb and bom files? I just got a OBSX and would love to build this. Cheers!
Hi, thanks for your interest, no BOM or PCB design available, it was hand wired on protoboard like all of my projects. As it was a custom paid job I never released the code or schematics either but I see no reason why that can’t be made public now the development has closed and I don’t intend to do anymore with it.
I will open up the GitHub page over the weekend
Of course you will need to purchase a magic box as well to use it as the obsx has no midi ports.
Here is the repository location, unfortunately I never drew a schematic, but if you look at the HWcontrols.h file its quite easy to work out how the MUX is connected to the Teensy 4.1 and what buttons/leds/pots are connected to the 74 HC165, 74HC595 and 4051 mux chips. If you look at top of the main ino file you will see what pins are used for the data/clock/latch lines of the 74HC165 and 74HC595 etc, MIDI is on Serial 1, so thats pin 0 & 1, the encoder and programming buttons are listed in the HWcontrols file and the display pins are listed in the ST7735Display.h file. So it should be straight forwards enough, it will power up from a standard USB port.
Update, I found a schematic, it will compile with warnings as it uses an older version of the settings menu that is now superceded and also the circularbuffer error, you can easily fix that by renamining the library extension to .hpp
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