@JohnYang1997 Congrats on this stellar design! When I was on the Apos website, I was blown away by one of the pictures listing specs. It was showing maximum output voltage swing of 49Vpp in balanced mode. This seemed ground breaking for an integrated solution. Now that I see the PCB showing the power supplies, I don't get it. The TPA6120A can only swing +/-12.5Vp (assuming symmetry which it slightly isn't) on +/-15V rails. Each chip looks to have its outputs in parallel through 3.3 ohm resistors (not sure how that drops down to 0.1 ohm on the output but must be due to the feedback loop). Each chip is a phase of the output (L+,L-,R+,R-) so that is 25Vpp on the balanced output at max gain.
I'm not sure where the 49Vpp comes from. Are you suggesting I buy two and parallel the outputs?
Sounds like a fun challenge but not what was meant here.
I'm just curious what I'm not seeing to come up with that number.
Thanks!
Michael