Beat707 Takes It’s Cue From A Vintage Drum Machine

We always like musical hacks at hackaday, so we were pleased to see the team at [Beat707] come out with their Beat707 MIDI groove box.

The Beat707 takes it’s inspiration from the venerable Roland TR-707. Like the Roland, the Beat707 can save songs and has MIDI In and Out. Unlike the TR-707, the Beat707 doesn’t have an audio out – it’s purely MIDI based. Don’t think of that as a drawback, though. Just connect the Beat707 to your favorite softsynth and start jamming out.

The Roland TR-707 was heavily used by acts like the Chemical Brothers, Aphex Twin, and the Cocteau Twins. Because of this history, the popularity of the TR-707 has exploded over the past few years, and getting a hold of a real TR-707 has been an expensive proposition. While rebuilds of vintage synths like [Ladyada]’s TB-303 clone, the x0xb0x have been around for a while, we’re pleased that more projects are paying their dues to the great music machines of the 1980s.  Do any hackaday readers want to tackle an 808 or 909 for their next project?

Video of the Beat707 after the break.


19 thoughts on “Beat707 Takes It’s Cue From A Vintage Drum Machine

  1. It’s a MIDI sequencer. I don’t understand why the board is so complicated. You need a low-speed UART for the MIDI (could be bit-banged), an LCD (needs a small handful of I/O lines) and some switches and LEDs. Why is this not just a single chip (microcontroller) and some buttons?

  2. @Andrew – It’s not really as complicated as you make it sound. There are no schematics, but if you look at it and the descriptions… most of the STUFF on the board is extra memory for SONG storage, proper MIDI interface circuitry, lots of jumpers and such to make the board compatible with a ton of different Arduino varieties, and you need a bunch of I/O for the LEDs and Switches so they are most likely done with shift registers. Can you make one simpler that does all that? Great, go for it! You can sell the hell out of them for $50 and undercut his market.

  3. Just a few remarks from Beat707 directly. ;-)

    We used a shield format so you can use with a regular Arduino, a Mega, or even other compatible cards. So the user has its choice with a shield format.

    The software does all the job of turning this into a true MIDI GrooveBox, with 14 Drum Tracks and 2 Synth/Bass Tracks. And since you get the source code, you can always hack the thing out or even create your own code from scratch! :-)

    What else you guys want to know about?

  4. @Beat707

    1) Any plans to use blue LEDs, or different button cap colors?
    2) Can this be mounted in an enclosure easily, or is it designed to be used without an enclosure only?
    3) How much real time is left to play with in the code? I’m guessing it would depend on the tempo also, and maybe cranking the tempo up too high already bumps into the end of real time?
    4) Is the backlight on the LED PWM controllable?
    5) Is the MIDI interface fully midi compliant?
    6) How are the buttons and LEDs interfaced, i.e., what kind of hardware or multiplexing scheme is used?
    7) How long did this project take to complete, from concept to now?


  5. @Brett

    1) Uh….no plans but we can work something out for custom builds. Contact us for details.

    2) It’s not really designed for an enclosure at the moment, but it should be simple to come up with a simple faceplate for it.

    3) The code uses a 16-bit Timer for the Midi Clock. There’s still tons of cycles left to add custom things. A bit of RAM and Flash Program is also left. But you can always remove stuff and create a totally new code with everything you want. The source files include everything you need. And remember, Arduino is totally open.

    4) No, the backlight is controlled by a potentiometer.

    5) Yes.

    6) Shift registers are used for both the buttons and the LED’s. The shift registers are accessed using SPI.

    7) From a dream to a final product: a few years. From the actual start of putting down the protoboard and chips, into a final product, around 6 months. Coding the thing out? Around 4 months.

  6. Nice idea! The 707 was a pure rompler so there is actually no need for any on board audio playback as any sampler can do that.

    What I’m curious about though are what all the chips are for, looks like opamps? If you use an arduino like that you will only need a couple of multiplexers for the buttons/ leds and some optoisolators for the midi. That would be easy to do with throughhole components making it more diy friendly.

  7. The chips in the board are In/Out Shifters. We have 16 Buttons, 16 LEDs, 8 extra Buttons and 8 extra external Buttons. A total of 64 I/Os, while the Arduino only have a few I/Os. Therefore, we had to use extra chips to add extra I/Os to the system. The rest are mostly resistors, for the buttons and LEDs, and also capacitors and other things. This makes this shield Arduino 2009/Uno compatible. Plus, we added external EEPROM and Nand Flash for storage, check the product’s description. Them there’s the MIDI Input/Ouput chips, LCD components and external headers, for MODs and expansions. ;-)

  8. And, surprise, surprise, I am working on a 8-bit rompler named Beat707 Vox. Its a small shield that plugs into a regular Arduino 2009/Uno and turns it into a 6 voice Rompler. I’m waiting for it to arrive on the mail. ;-) I already did that and posted some videos on YouTube a while ago. It was using a regular Arduino Flash Program to store samples and 2 PWM outputs (10-bits) for the output. Samples were stored in 8-bits. But the sound was pretty good. It had velocity and tune mods per voice. Soon we will have more info about that… just keep in mind that its an external thing, requiring another Arduino board just for this.

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