For years I had my friend Dr Chill’s TB-303 in the studio, where it took care of all my acid requirements. Then he wanted to buy some land in Colombia, so I had to sell it for him. I borrowed a TB-03 for a while, but didn’t really like the sound, so I knew I needed an acid machine of some sort.
I’d heard about the x0x-heart project, an open source clone of the analogue section of the TB-303, recreated with SMD components. The heart PCBs were available pre-populated, but I wanted to build my own, so I reached out to the DIY community and found a board, along with the “pacemaker” panel board in Michigan. The guy sold it to me very cheaply (I think the postage from the states was more) and I picked up a panel dirt cheap from Pusherman.
Lots of people told me I was crazy, that they’d tried and failed to build the heart board, and that I should just buy a pre-populated one. They were probably right in retrospect. It’s a super hard build. The transistor pairs (the same package that had screwed me right up on my first SMD build) were very tricky and there are loads of them.
There’s a bit of fiddly wiring (I love the wiring!) to connect the two boards.
I was thrilled when I plugged it in and the acid came pouring out!