Because of changes that were required in the first prototype, and then getting a bit more inspiration from a recent DIY THT build project, I decided to create a new hybrid prototype that would allow either a ESP32 SMT module or ESP32 THT DEVKITC to be utilized.

Note: Although the silk screen shows a ESP32 part number with a '-IE' suffix, the cheaper version with an '-E' suffix can be substituted instead. The only difference is that the '-IE' version has both an IPEX and PCB antenna, whereas the '-E' only has a PCB antenna. Keep in mind that the one with the IPEX connector has this selected by default, and needs to be modded to use the PCB antenna instead by moving resistor R14 to the R15 position (refer to diagram - click to enlarge).
This board is currently being manufactured by JLCPCB in China, and has an expected completion date for this coming Monday.
When I get at least one board assembled and tested, I'll be sure to post the updated schematics, as well as my observations. So far I can tell you that it incorporates the same SIO interface as its predecessor, using a 74LS07 and a 74HCT4066. This new interface has been working very well, and appears to have solved the audio noise issues.
- Michael
This board is currently being manufactured by JLCPCB in China, and has an expected completion date for this coming Monday.
When I get at least one board assembled and tested, I'll be sure to post the updated schematics, as well as my observations. So far I can tell you that it incorporates the same SIO interface as its predecessor, using a 74LS07 and a 74HCT4066. This new interface has been working very well, and appears to have solved the audio noise issues.
- Michael