Every generation has an instrument which defines its sound, and for those whose formative musical years lie in the 1980s, a very strong contender to the crown is the Roland TR-808 percussion synthesizer. Its sounds can be recognized across a slew of hits from that era and every decade since, and though the original instrument wasn’t a commercial success it remains accessible through sample packs, emulations, and clones. The 808 was an all-analogue device that didn’t use samples, thus [Mark Longstaff-Tyrrell] has been able to reproduce its distinctive cowbell sound with reference to some of the original circuitry.
It shouldn’t come as too much of a surprise to find that the circuit is refreshingly simple. The trigger pulse is converted into an envelope which controls a pair of oscillators. The mixed output passes through a bandpass filter to create the distinctive sound on the output which you can hear in the video below the break. The circuit is recreated on a breadboard with the only concession to modernity being a microcontroller taking the place of the Schmitt trigger oscillators in the original.
Altogether it provides a fascinating insight into the synthesis behind a classic sound, and gives us an increased appreciation for the design skills of those Roland engineers who created it. We’ve looked at the 808 before a few times, including an explanation of the famous faulty transistors which contributed to its sound.
If you spent the 1980s hanging out at your local record store, and you don’t have a hankering for spandex and bouffant rock-god hairstyles, the chances are you’ll have more than a few pieces of electronic music from the period in your collection. The proliferation of electronica during that era came through the arrival of relatively inexpensive mass-market digital polyphonic instruments, edging out the sounds of monophonic analog synthesisers for a subsequent generation to rediscover in a later decade. Individual instrument models became icons and entered the musical vernacular of the day, the Ensoniq Mirage sampling synthesiser, the Yamaha DX7 FM synthesiser, or the Roland TR-808 drum machine.
It is the Roland TR-808 that inspired today’s subject, the MR-808 robotic drum machine, from [Moritz Simon Geist]. A percussion sequencer featuring real instruments all built into a cabinet styled to resemble a huge Roland 808. Originally built as a performance instrument, but since reinvented as a piece of installation artwork that visitors can program for themselves.