A 10uF capacitor between the power supply pins (VCC and GND) and a 100nF capacitor between the BYPASS pin and GND are recommended for proper decoupling.
The gain of the LM386M-1 can be set using an external resistor and capacitor between pins 1 and 8. A gain of 20 is the default, but it can be increased to 50 or 200 by adding the correct components.
The maximum power output of the LM386M-1 is 1W into a 4Ω load, but this can be increased to 2W with an external heat sink.
To reduce noise and hum, ensure that the power supply is well-regulated, use a low-ESR capacitor for decoupling, and keep the circuit layout clean and compact. Additionally, consider adding a noise filter or a shield around the circuit.
Yes, the LM386M-1 can be used as a headphone amplifier, but it's not the most suitable choice due to its limited power output and high output impedance. A dedicated headphone amplifier IC would be a better option.
LM386M-1 datasheet
by Texas Instruments
