The lion kingdom still remembers when the most $10 would get were the cheapest, tiniest, most horrible sounding speakers which plugged directly into a walkman. The sound was completely unintelligible, but what a novelty in the old days to hear a walkman through any portable speaker.
There should be no disappointment in 25 years later, what would appear in Walmart but $10, Lipo powered, bluetooth speakers which actually sound as good as a boombox did. It's not just a case of something getting cheaper by getting smaller, but a lot more getting cheaper.
The purpose of this was not the speakers, but to gain a bluetooth receiver for a lot less than $parkfun's $25 bluetooth audio module. Managing the headphone cable had become quite a chore in 6 months of driving around with it. Sadly, the new speaker would be too heavy & quiet to use intact. It would require a much bigger robot to move around a decent speaker & loudness has taken precedence over quality.
The teardown was completed & the electrical signals probed.
It uses ANT8110 class D amplifiers which take 5.5V & output 3W. The only datasheet was purely chinese except for 5.5V, chipsourcetek, 3W, & class D. Though the reduction in voltage would be a huge convenience, it wouldn't be as loud as the 6W TDA1517.
The receiver is a Beken BK3254. Analog audio comes out of 2 pins at line level.
It requires 4.2V power at the battery terminals to power the ampilifier. The receiver can work on
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