4 ms·
A very basic datasheet for the M51516 can be found here: https://datasheetspdf.com/pdf-file/635283/ETC/M51516L/1 https://datasheetspdf.com/pdf-file/635283/ETC/
by squarefoot 5y ago
A very basic datasheet for the M51516 can be found here:
https://datasheetspdf.com/pdf-file/635283/ETC/M51516L/1 https://datasheetspdf.com/pdf-file/635283/ETC/M51516L/1
The dual capacitor on the output isn't really needed and it just filters out more bass sounds since essentially there are two capacitors in series.
It seems who drawn the circuit adapted it from the stereo version without much thinking.
Actually there should be no need for output capacitors at all if the internal amps are well balanced, but that should be checked with a multimeter before removing them. Good thing the Zobel network wasn't omitted, but there should also be some good capacitive decoupling on the chip supply lines to avoid motorboating and other noises.
Anyway, to get the right supply voltage the best approach is to raise +Vcc through a switching step up regulator rather than using a charge pump negative supply as they can't give the necessary current.
I probably have a few of those chips in a drawer, iirc they're used in some HAM radio equipment from the 80s, but if I had to repair a circuit using them, I'd solder a small cheap Class-D module in place of the chip since they're a lot better in pretty much everything. Probably not the preferred solution for restoring old games boards though.