I'm reviewing a schematic so that I can replicate it and I've come across several labeled inductors with no values. From my Googling, It seems that these may actually be ferrite beads. My question is, what kind of ferrite beads should I populate here?
L3, L4, L5 and L6 sit between a 1W audio amp and the output. L8 sits between a single wire data bus line, for reference.
Additionally, on the first image near R18 (left side of the schematic) the ground is pointing two directions and there's an arrow with a line through it, which I can't find the meaning of via Google. Any idea what's going on there?
Audio Preamp circuit:
Power and I/O: