Tuesday, July 9, 2013


this was a quick little project i threw together for some good friends that i had recently visited in Barcelona. i had built something similar for another pair of friends who got married last summer. unfortunately i forgot to take any pictures or video of it before i gave it to them. oh well, they just live down the street. the danana box is basically a heavily modified animal keyboard. actually now that i think of it, it was a guitar... the guitar had 15 notes that were all trigger-able through a common bus(4.5v), so i hooked them all up to a CD4067 analog-multiplexer. the 4 binary inputs are driven by a 74HC193 up/down counter chip which in turn is clocked by a simple 555 oscillator. the four bit word coming from the 74HC193 are fed to the binary inputs of the CD4067 via 4 momentary switches. there is then a momentary switch to change the direction of the up/down counter. if none of the four bit-buttons are depressed, no sound will be made, but any combination of the four switches pressed will produce one of 15 melodies(possibly coprighted by googltubes). the up/down switch changes the direction of the melody. the box has 5 different sounds to chose from. at some point these were sampled animal sounds that had a weird kind of echo to them. this made for a unique set of sounds when overclocked to the point that the animals are indistinguishable. the main voice is then sent to a pt2399 delay chip. on one side of the box is a yellow joystick. on one axis of the joystick, the frequency of the melody can be changed. on the other axis, the delay rate can be modulated. the whole thing runs off batteries and has a built in speaker. one unique aspect of this build is that because space was so limited, i decided to build all of these circuits without PCB. instead, all of the components and chips are all just blobbed together like big circuit boogers. i had never attempted building circuits like this before but hey, it works. i should have taken some pictures...
check out the video n'stuff.

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