“While maintaining compatibility with previously supported Raspberry Pi models, the new Pisound v1.2 has been updated to work perfectly with the Raspberry Pi 5, ensuring compatibility with the Raspberry Pi Active Cooler.”
Can I stack the Pisound 1.2 on top of Raspberry Pi 5 + Active Cooler + PCIe M.2 HAT with a 2230 M.2 NVMe drive? Will it just fit, or does it need some further adaptation?
Looks like the PCIe M.2 HAT has a female header on top, preventing further stacking of HATs, so it doesn’t look like it would work with Pisound without converting its female header on top to one with male pins, I can’t locate official suggestions how to do that.
Otherwise, if Pisound could be stacked on top of the M.2 HAT, it should work - the GPIO pins used by Pisound seem available.
It wouldn’t fit into the Pisound’s Acrylic Case obviously. 
Looks like the GPIO header pins could protrude through the PCIe M.2 HAT+ board, as can be seen in this picture:
found on this review article.
A comment on the article by BRET says:
Only if they use the GPIO pins and not the PCIe connector, oh, and you’ll need to buy a longer GPIO extension as the one included doesn’t actually go all the way through the ports on the M.2 HAT+
It sounds like it’s possible to stack additional boards on top, but you must source a stackthrough header that is longer than the one provided with the kit.
One source of such headers is Toby Electronics.
REF-187026-03 might be long enough.
Keep in mind I haven’t tried this myself, just sharing some ideas on how to go about getting Pisound to work with the PCIe M.2 HAT+ underneath.
Nice, this should work! Karma, a 16mm stacking header seems to be provided with the HAT. 
