Amplifiers

Most of these are class D unless noted. I like class D most of the time.

National series

• LM386 noise outdated analog pretty cheap inefficient class AB but not really cheap compared to better newer amps
• LM4853 "Boomer" costs too much, love that product line name "Boomer" I mean ???
• LM48560 piezo / haptic driver

• TDA2005 -- I have a FutureKit that's been on my bench forever and I might replace it soon just to try out something else.

• TDA2050 high output obsolete class AB
• TDA2822 $4.5 obsolete
• TDA7266 7W+7W I have one around somewhere -- https://www.mpja.com/Adjustable-Stereo-Amplifier-Module-TDA7266/productinfo/31806%20MI/
• TPA2012 see adafruit
• TPA2016 has a control channel over i2c which is pretty neat, I think Adafruit has a breakout for it

Diodes Incorporated "PAM" series

• PAM8302 mono chip is around $.40 Adafruit breakout is $3.95

• PAM8403 very common very quiet obsolete I have 2 from All Electronics MPJA has them for $1.75
• PAM8406 upgrade to 8403 chip is $.84 and boards run around $1-$10 I ordered a couple spendy ones from Amazon, about $7 each

The PAM8403/PAM8406 has a mute control and PAM8406 has a mode control (Class AB or Class D) and a "shutdown" control and sometimes those pins are not brought out. The PAM8406 boards I bought today has a 2 gang volume knob and both those signals are available. I think mode, mute, and shutdown are usually tied to ground. Shutdown puts it in a uA mode and mute just stops output.

Read the design notes, they specify components to use to reduce clicks and pops. I doubt the $1 China boards pay much attention to that? The PAM8406 should have ferrites on the outputs. See the data sheet https://www.diodes.com/assets/Datasheets/PAM8406.pdf and eval board https://www.diodes.com/assets/Evaluation-Boards/PAM8406-User-Guide.pdf

There's a MAX58937 or something from Adafruit that has an i2s input instead of analog. It's around 3W

I have several i2s 20W boards including one in my junk box