I've had to switch gears and migrate to digital software synthesis. It was just becoming the case that I could get more done on a given Saturday with software then I could with soldering or breadboarding analog circuits.
The Raspberry Pi3B showed a lot of potential for electronic music synthesis when I first encountered it in 2018. Later on, for independent projects on radio, I set up several Raspberry Pi4B units to drive various Software Defined Radios. The 4B is an incredible machine for DIY
Using some admitedly crude metrics, I determined that a single $35 Raspberry Pi3B had the functional equivalent of a system made with 2500 LM3900 op amps. I had been developing electronic music circuits with these op amps for years
, they are really interesting. The equivalence of course is not exactly the same as a system that might have been composed of such a large number of linear circuits, only approximate. However, for the case of a Raspberry Pi4B, this equivalence was more like 10000 LM3900 op amps.
The only problem I had with a Raspberry Pi synthesizer is that the available HATs either offered excellent CODECs for audio, but no convenient utility for realtime user interfaces; or there was all you could want for user interface coupling, but not for audio I/O. I was not inimical to making new hardware, but I felt like making new hardware and having to have all the low-level software in order to do anything with high-level software was a longer project than I wanted to take on.
As it happened, I subsequently found the Zynthian 4.2
, which had SDIY hardware that covered both bases: UX and audio. And it was already highly integrated with a low-latency Linux distribution, with all the necessary low-level support for the hardware bundled in. As well, it's an open platform, ready for hacking and discovery. And, it had been recent upgraded to the Raspberry Pi4B.
That was the turning point for me: I recently built a Zynthian. It's a power-packed little box, absolutely amazing this much sound generation and signal processing can be done in software!
More detailed notes on my SDIY build of the Zynthian are in my Electronic Music Synthesis blog