I am thoroughly musically untalented, but I like to build stuff with the kid that has an immediate payoff. We’ve made a few game machines, uncounted blinkenlights and we’re now in the process of building stuff that makes noise.
We’ve progressed from the Atari punk, through breadboarding various circuits, Arduino & dupont horrors and wire monstrosities that fall apart if you breathe wrong and are now mining Github etc for cool projects that have a PCB designed.
We’re in the middle of making:
Drumkid - Got the SMT PCB, this may have been over-ambitious as the parts are significantly smaller than the 0805 I’ve built with before. Should’ve got assembly with the PCB for the small bits 
AcidBox - Looks fun and definitely fits the makes noise immediately requirement. Waiting on a few parts from China.
EDIT: Only 2 links in a post Search copych Acidbox on Github
Fizzle Loop synth - Can’t get started, neither of us wants to make it, dunno why it looks great.
EDIT: Only 2 links in a post Search instructables 555-Fizzle-Loop-Synth-V4
Stuff We’ve built (just the PCB stuff)
BeatMaster 2000 - Good fun, makes terrible noises. Went through 3 builds before trying better caps, better pots and now it makes beats not just SKREEEEEEEEEEEE!
EDIT: Only 2 links in a post Search instructables
MiniPops - Great fun to mess with, PCB was not great, I may have messed up in KICAD, some of the holes were incorrectly sized and I absolutely could not find toggle switches with through hole mounts. Couple of resistor legs to replace the two inside pins on the arduino and some small switches (which I now have 200 of…) and it pops away. Sounds surprisingly good through an amp.
Ayone got any more suggestions of wonderfully beepy stuff with a PCB or a very easy schematic (my KICAD skills are also minimal)?
And is there any approved place to do swaps? I’ve got at least one spare of all those PCB’s along with a few Arduboy and other bits and selling OS stuff seems wrong.