The Source Audio C4 allows you to edit and upload patches from the ‘Neuro’ app. Stack up to 4 voices to create your own patch. And the Roland TR-808 drum machine was one of Roland’s first fully programmable drum machines, manufactured in the early 1980s. The TR-808 went to be an essential sound in Hip Hop and popular electronic dance music styles. It has been used on more hit records than any other drum machine.