New revision of the Amped-ESP32-S3

New revision of the Amped-ESP32 just came out. There is just one difference compared to the previous board – the TPA3118 amp came in to replace the TPA3128.

The TPA3128 is a better amp on paper, and it came to replace the TPA3110 amp used on the earlier revisions for three reasons

• Better efficiency, and therefore better power figures
• Possibility to work from 5V, so it can be used with USB power only
• True MUTE pin (TPA3110 only has STBY pin, which causes audio pops when switching on)

Unfortunately, I found that the MUTE pin is not entirely pop-free (tons better than TPA3110, but still not there by my standards), and the higher sensitivity of the TPA3128 input caused it to pick up Wifi noise in certain conditions.

So, TPA3118 comes to address these issues. And it does 🙂

• MUTE schematic is updated to slow down voltage ramping speed on turn on – this helps reduce pop noise to “I can no longer hear it” level
• Modulation is hardwired to BD (1SPW is more efficient, but caused pops as well)
• Gain is fixed at a 20dB level – also helps with pops
• I added a band-pass input filter network to make sure it is noise-free.

Now that I am entirely happy with its performance, I’m going to migrate the same schematics to all Amped-ESP32 and Amped-ESP32-Plus boards.

All the design files and schematics are available on GitHub