For the LM3886 to work well, you need to provide it with two local decoupling capacitors for each voltage rail: 100 nF || 10 uF. I take it a step further with modern parts with 1 µF X7R in parallel with 22 µF electrolytic. You can read more here: https://neurochrome.com/pages/supply-decoupling
If you skip the decoupling you'll find that the LM3886 will oscillate near clipping with a 4 Ω load.
Neat project, though.
Tom
If you skip the decoupling you'll find that the LM3886 will oscillate near clipping with a 4 Ω load.
Neat project, though.
Tom
Thanks, sure, you can't see them on the PCB, but the pads are planned for 470uF and 100nF near the chips. It works on paper, but it's been pending for 10 years.