MIDI-Controlled Intellivoice Synth

Mattel Electronics presents…



It’s been a long time since I started this project, but I’ve finally got my Intellivoice Synth running.

Since last time, I added MIDI control and transferred things to a smaller circuit board (and Arduino) in order to fit everything back in the original case.


Working out how to get the new guts into the old housing


USB MIDI control, 1/4″ output

So what does this little synth do? It takes MIDI notes (from a keyboard or DAW), and uses them to trigger the sounds built in to the Intellivoice chip, which, as it turns out, consist of mostly numbers.

Check it out:

I might look into a few more tweaks. Currently, each word will always play to the end, even if another word is performed before it’s finished. I’m not sure if this is a property of the Intellivoice chip, or something I could fix in my Arduino program.

Why pursue a project like this one?

Games and gaming hardware are mass-produced devices with planned obsolescence and few serviceable parts. By “hacking” and customizing gaming hardware we regain personal ownership of these devices, and we can turn obsolete equipment into performable, expressive instruments.


A few last-minute modifications to the audio-chain

An earlier version of this synth actually appears in the electronics of my new commissioned work, Hirazumi (more about the piece here and here), and I think the hacked Intellivoice fits perfectly into the post-digital, cyberpunk aesthetic.


  1. Skannotto says:

    Is the box of tissues for the tears of joy when something works correctly?

  2. Simon says:

    Ha! They do kind of steal the show in the video there.

    Sadly, they were actually for getting the rust and crud out of the casing:

  3. Intv Prime says:

    How is it powered? Would you consider making this into a DIY kit so others could do the same thing? That is pretty cool!

  4. Simon says:


    The power is just from the USB (so from the computer’s USB port, really).

    A DiY kit is a cool idea, but perhaps writing an “Instructable” is more up my alley. Mostly I just took this guy’s tutorial setting Arduino to talk with a different SP0256 chip – http://nsd.dyndns.org/speech/. I took his/her code, adjusted it to match the Intellivoice built-in sounds, then added MIDI control.

    Here’s my final Arduino code.

Leave a Reply

Your email address will not be published. Required fields are marked *

Event Calendar

February 2016

Upcoming Events

  • No events.
...by admitting a new perception of space and giving it an active sense, is it not possible to discover a new unexpected, unexplored world?

-Takemitsu Toru