Open the bottom plate, remove the cable plug that lead from the DAC board to the tube board, you will experience a major upgrade of the sound. From the solid state output only, of course. This tweak is reversable, so you will not loose anything by trying this.
The other thing you can do is remove the bottom cover that is in the middle section of the digital drive, and also do not put the main bottom cover back. This will relieve all the RFI that had been bottle up inside the chassis and will give you another boost of performance.
Finally if you have your own pre-amp and do not need the volume control of the Shanling, unplug the direct out cable from the DAC board, and plug it into the the empty socket on the left side (looking from outside the upside down CD player) that marked 'Front Out'. This will not only bypass the volume control, but also some very bad electrolytic capacitor. Another reversable tweak with the highest level of sound improvement.