An update regarding the most recent batch of TDA1387 X8 modules I have received from HuaXinHuiDianZi Store. Rejection rate is now about 10%. Those are ones with poor channel balance, and indicate one of the chips is bad in one channel. About 2/3 are balanced and measure in the 1.20-1.30 VAC RMS with 0dB 50 Hz sine wave (Fluke 11). These are the ones I ship with the kit. The other 1/3 of the "good ones", which are balanced and measure in the 1.10-1.19 range. I have listened to these and they sound perfectly fine.
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5
Software: Moode 8.3.3
Source: Win 10 NAS
Software: Moode 8.3.3
Source: Win 10 NAS