Using the same principle as the LED strobes that enable fine-tuning of turntable rotation speeds, this DIY “Acid Machine” synth has a cool way of visualizing its sound: A rotating disc printed with a ...

Here’s Pure Acid with a fetching gold makeover. Photo: Charlie Sorrel/Cult of Mac Pure Acid is a bass synthesizer and drum machine app for the iPad, and it might just be the best drum machine app ever ...

This machine works by making a LED blink in the frequency of the sound and a set speed rotates the image. On top of the machine is the circle that contains lines where the notes being played are ...