Lorre-Mill uTone Full DIY Kit
This electronic instrument project began with an experiment of walking ring counters. The basis of the design is that feeding outputs of a shift register back to the input through a logical inverter creates this rippling bit effect where, all ones then all zeros are passed down the line. When mixed by a resistor ladder this feedback renders "sinewaves" of different pitches, or noisewaves of different lengths if fed back thru exor. This utone circuit uses CMOS logic, a resistor ladder, and a few other simple pieces to create audio forms. The scale inherent in this instrument is the undertone series, giving divisions of the main clock frequency.
I built this keyboard to tap the different outputs of the shift register and there were these pitches, divisions of the clock by 2 through 16. I consulted the finely tuned ears of the Owen Gardner (of Horse Lords ) in order to identify the scale. He responded over sms message using only cowboy language and western slang to describe the series.
How's my driving? There is a Micro-power PLL chip, the CD4046BE, which is used for its oscillator and exor gate. There are two CD4015BE shift registers shifting 16bits, a TL072 for buffering and such. There is an exponential current source for controlling the oscillator and there is a logic inverter for cycling the shift register. From each output of the shift register chips there are two resistors one 102 going to the touch-pad associated with the put, and another of a higher value to mix with the rest of the stages in the resistor ladder.
DIY-ing this design
I love diy-ing things! Here is a schematic painting of the utone design and some notes toward construction. In the picture below you can see yellow shapes along the bottom of the frame. These shapes denote octaves, evens, and odds. The squares are octaves, circles are odds, diamonds even. In the noise modes the odds tend to give longer noise patterns and evens will give more pitched, shorter noise patterns. In the painting it says 102 for the 4046 cap, in the right angle it says 470... it's up to you. Also you could use different values for the resistor mixer in order to mix less of a sine wave and more of a special wave.
This electronic instrument project began with an experiment of walking ring counters. The basis of the design is that feeding outputs of a shift register back to the input through...
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