TR808 kick drum synthesiser

I thought I had already written about the bass (‘kick’) drum synthesiser in the Roland TR808 but, searching the Electronics Weekly archive, I can’t find it.

Bridge T drum synth

Hearing of the death of its inventor, Ikutaro Kakehashi, reminded me of it.

The particular kick drum sound is heard on many famous synth-band tracks, and the band 808 State took its name from the machine.

The circuit is essentially an op-amp with a bridge-T filter in its feedback loop – see diagram.

In the Roland design, it is a bit more complex – Mr Google will find you a full circuit, like this one.





  1. The TR808 was one of my favorite drum/beat sounds growing up. It also inspired me to explore electric drums and electronica in general.

  2. Getting to build something like that sounds like heaven.

    My new soldering iron has seen very little use :/

    So I was wrong about fingers flashing over black and white keys… how about the shirt?
    My mental image was a little Rick Wakeman-esk.

  3. The Chorosynth is solidly monophonic apart from the weird choral sort of processing that it can do.

    One of my mates built one back when it was published in a magazine, he being the lecturer teaching on the Music Tech course.

    Apparently the original he built got left in a loft somewhere so I built another to see what it was like.

    Sadly the only keyboard my fingers flash over these days has 102 keys. πŸ˜€

  4. > Er, what was your previous impression of me? Just askin’ like.

    It didn’t include long hair, a colourful shirt and flashing keyboard fingers – which it does now πŸ™‚

    Chorosynth keyboard looks a little Stylophone-ish – so mono-phonic?
    Having googled Stylophone, I just came across the Stylophone Gen X-1, which looks a little Chorosynth…

  5. Of course that was when this institution still had a PCB facility so I could prepare PCBs for the esteemed customers to build stuff with.

    Sadly the inevitable H&S review has put a stop to that.

    One of the last music type projects was a version of the “Chorosynth” that sort of works apart from the lowest 3 notes.

    It was the fun of doing stuff such as this which made an otherwise tedious job bearable.

    But with less than 400 days to retirement, I’ll just have to put up with it for now.

    Er, what was your previous impression of me? Just askin’ like.

  6. My mental image of you zeitghost has just changed πŸ™‚
    I have made guitar amplifiers and effects in the past, despite not being able to play a note.

  7. Ah, back in the day, i.e. about 3 or 4 years ago, when the Music Technology course still had actual electronics tech in it, we made up a set of analogue effects modules much like, but simpler than that.

    It was fun.

    And the stuff sort of worked too, which was even better.

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