I've just built this portable powered breadboard. It contains 2 separated linear power supplies. It runs on 6S Li-ion battery pack. It is very quiet on my opinion. It good for op amp circuit.
You can download the layout here:
https://drive.google.com/file/d/1L4kuE60_DInYH8UiqH2ef2tArzV5VCaX/view?usp=share_link
