Parts order placed

I have some CMOS TLC555 timers on the way. These are extremely popular because everyone knows how to use a 555, but the SynthDIY community likes the CMOS version because it plays nicer with our power supplies. The downside is that they cost significantly more per chip. Juanito Moore mentioned using a NE555 in one of his circuits and responded when i asked him about it:

All my NE555 designs have a ~150R resistor inline with the power rail with a big old cap, usually 100uF to ground. I have a whole raft of NE555s because they're ssssooooooo cheap, but managing their cruelty to the power rails does require design tweaks

 Food for thought, anyway.

Begrudgingly, i've also ordered some MCP4822. It seems like they will be pretty simple to use with the ATTiny84 / 85, but i also still believe that some pitch accurate CV out is possible without the DAC, even if it's only 3 octaves and takes both PWM pins to do it... The thing that finally sold me on it was that the Mutable Instruments CV Pal is open source and uses essentially the ATTiny84 with the MCP4822 clocked by a 20Mhz crystal. I'm speculating that the xtal is the secret sauce to getting the '84 to decode MIDI accurately. I'd like to see it support regular old Serial MIDI (ie, DIN5 connector) though, so it will need some additional code for that. Overall, the whole thing is Stripboard Friendly, which is how i like to roll. Maybe i'll upgrade to proper panels and chinese PCBs in the future, but i love the garage aesthetic for early work. I feel a connection to the early synth pioneers when i work this way.

I finished up stripboard construction of Module #004, the prototype MIDI CV module using Kevin's code. Hoping to test it out later today while the construction crew works on my staircase - tell the truth its hard to get "real work" done with all that racket. The particular DIN5 connector i chose is really not well suited to my panel construction method and will be a total bummer to cut.