Did you take it any further? I went ahead and wired it up and it all worked well for nearly 10 minutes and then it had enough and just stopped. I was disappointed, frustrated, and had spent enough time pretending like I knew what I was doing so I haven't been back to the project to see if I even have a functioning unit to continue working on.

I'm thinking I fried the TPA3110D2 amplifier chip.

I'm also wondering if adding headphones is feasible at all. Is there a crossover circuit onboard or is Amazon creating a stereo audio stream that is already frequency divided (L=woofer, R=tweeter)? If so, capturing the inputs to the TPA3110D2 may still require blending the signals with diodes or something to prevent a burnout.

If I did fry it, at least the thing is heavy and kinda doorstop-shaped...

Hey TM! We would love to know some details on how you tapped the signal. L=Woofer,R=Tweeter, or did you somehow combine the two into a meaningful sound? I'm trying to hook up headphones for a hearing-impaired elderly user. W was too thundering and T was too sharp. I hesitate to just join the two blacks and two reds, but I might just try it.