Hi All,

It's been quite a while since I checked in on this project, but realized there was a super cheap upgrade that is almost a 'why not' for anyone with decent soldering tools!

So the TPA3116D2 is rated at 50W into 4ohms, and in that same family of amp chips is the TPA3156D2, which is 70W into 4 ohm.... it's a drop-in replacement, just has 20W more power with the same exact specs. 
(highest upgrade that seems available as a drop-in replacement)

You do need a decent hot air station (or something similar) in order to heat the chip up enough to remove it, and because there's a good amount of GND connections to the chip and gnd planes under it, you really need to heat it up high.... I'd recommend 350C or higher... I was at about 325C, and it wasn't quite enough, I ended up damaging a small trace being a bit too aggressive and i didn't get enough solder good and melted...

You can get the TPA3156D2 for about $4-5 or so, I just bought a pack of 5 from mouser...

https://www.mouser.com/ProductDetail/Texas-Instruments/TPA3156D2DADR?qs=W0yvOO0ixfHhsPcFy51aQQ%3D%3D

I did a quick test with a DB meter on my phone, about 6 inches away from the speakers, running a few acoustic songs, and then did the same test with the upgrade, looks like at least a 5db increase at least at full volume, seems good to me!

** note:  the increase may even be much more than that, I realized I didn't even have my bluetooth source volume pushed up... so it gets super loud now :)

**

you definitely want to use a good amount of flux to clean up the pads after the chip removal (ie flux and copper braid)... and then use a good bit of flux when soldering, to help prevent bridges!

Pic of the original TPA3116D2 (heat sink removed)

Pic of the board with the chip removed (notice the small damaged trace from not enough heat and me being too aggressive..

Final pic with the TPA3156D2 installed (before applying new heatsink compound along with heatsink)