GTA02 bass fix
Here I'll try to describe my take on rework that should radically improve the ability to use FreeRunner as a portable music player.
A known issue is that output decoupling capacitors are too small, only 1uF (4.7uF in v7). One of the possible fixes is to add some decent 100uF C in parallel.
I used two 100uF 10V tantalum caps. They should be connected in parallel to C4110 and C4111. Make sure you connect the plus terminal (marked with a thick line) to the side that goes to U4101.