As evidenced by Tindie’s robust Sound section, audio hacking is alive and well. Though this can take many different forms, a very versatile tool for transporting electronic music signals is the MIDI, or Musical Instrument Digital Interface standard. Though originally meant to allow digital instruments and computers to interact with one another, these signals can be translated into physical outputs, such as the Robotic Drum Kit seen below:
Physically, the setup of these drums is simple enough. Actuators, most likely solenoids, cause devices to play the percussion instruments, but how does the signal get from computer signals to the solenoids themselves? You could hack something together to do this, but if you’d rather concentrate on the music, another alternative is this Relay Switcher device.
This “8 Channel MIDI-to-relay module” takes in a MIDI signal, then uses it to switch eight isolated SPDT relays that can drive up to 10 amps of current capacity per channel. Given the massive amount of power it’s capable of switching, it can open up all kinds of musical possibilities!
On the other hand, relays can’t effectively regulate sound intensity through pulse-width modulation. To gain this type of control you need a different option. Hardware designer “Hotchk155,” offers a transistor-based switcher that has this capability.
If you’re considering between these to methods of switching for your next audio adventure, you can see the pros and cons of each device on this comparison sheet.