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TB-303 owner here. If my TB-303 sounded this bad I'd set fire to it ;-)
Really this is just an implementation of a basic oscillator, filter and envelope. No harm in that all and it's more than I could manage - it's fun and nice, but it's nothing like a 303. "Building an acid synth" would be fairer.
The accent and glide are core components of the sound, as is the really quite unique sequencer control - from the strange bendy growls to the classic acid bark the accent brings out. Would have been nice to see a deeper dive into why that is and why it's different from implementing a normal portamento-style glide as many other synths do, like the SH-101 - which cannot sound that close to a 303 due to that glide. Well it's also got a different oscillator and filter, with no accent either, but I don't want that to ruin the story ;-)
By UncleEntity 2026-03-1115:37 My project over the last week was to get the robots to train a neural net to learn the "303 thing", hasn't gone well at all.
The first one sounded like it was being played on a blown out speaker after it got run over and the second attempt sounded like it was going through a $20 pawn shop guitar pedal that got left in the rain which lead to the 'oh, you wanted the neural net to learn the 303's filter section? My bad, I just made some random stuff up as an approximation...'
The worse part is there's still compute credits left over from the initial ten bucks so we just have to try again...
> TB-303 owner here. If my TB-303 sounded this bad I'd set fire to it ;-)
Fellow TB-303 owner here. I concur.
By goatforce5 2026-03-1121:121 reply I, too, have a TB-303.
It seems like there might be a disproportionate number of 303 owners here on HN.
By Computer0 2026-03-1121:20 me too, and many clones...
By nekooooo 2026-03-1120:24 they should have referenced Rebirth - that one was spot on (i never owned a 303 though, just got access to one occasionally)
By wesz 2026-03-1122:13 What do you think about mine implementation? https://drumpatterns.onether.com/drumkit/roland-tb-303/
By bikesharing 2026-03-1117:28 [dead]
I'd love to see a deep dive into the 303 CPU and their replicas like https://www.sonic-potions.com/re303 and https://socialentropy.com/pages/product_qs303
sonic potions has an analysis of the cpu timings here https://sonic-potions.com/Documentation/Analysis_of_the_D650...
Theres also some nice articles about the diode ladder filter in the 303, similar to the one in the vcs3 https://www.timstinchcombe.co.uk/index.php?pge=diode2
By bloke_zero 2026-03-1114:33 There was a lot of work done on the RE_303 and the Pixie CPU (303/606) - I don't know much about it but it might give you another more recent vector to explore: https://github.com/sunflowr/recpu?tab=readme-ov-file
(I built one and as far as I know the Pixie CPU was the 303 code + MIDI)
By thr0waway001 2026-03-1118:023 reply I remember playing with Rebirth in the late '90s and then actually finding a real, TB-303, albeit with a bunch of drawn on crap. But it was very functional. Keeping it in a box for my daughter. She will either think it's cool or sell it after I'm gone. If she sells it, hopefully she gets some decent coin.
I'm kinda tempted to give it to my neighbor's son though. He knows about all this stuff and loves it. He'd appreciate it more. He’d also love my Roland D-50. He also comes by the garage to help out with stuff. Like the son I never had.
My daughter, though, does not appreciate this tech stuff whatsoever. Calls my gear room the ‘junk room’ .
By asdhtjkujh 2026-03-1118:401 reply Maybe he could borrow the D-50 to start! I wish someone had introduced me to hardware synths when I was younger; it took me years to find my way with no guidance.
By racl101 2026-03-1119:07 Yeah, same here. This stuff is cool. Wish I'd had a mentor.
By pgreenwood 2026-03-121:02 The web programmer is a handy thing for the D-50
By progmetaldev 2026-03-1120:26 You could always invite him over to check it out, just to see how he reacts to it, and if he's interested more in the tech aspect or the music aspect. Due to the increased rarity of the device, you'd probably want to find out if he would actually use the device, or try taking it apart to see how it works. I'm not sure how old your daughter is, but you could try asking her if she would be upset if you allowed the neighbor to play with the device, just to avoid any ill feelings.
It sounds like you've got some great options either way. I wish I had a neighbor growing up that had cool music gear (although I did get to grow up with a dad that got me into computers before I could read, so that definitely built my love for technology). Sounds like you're the kind of dad more kids these days need in their lives.
