It may or may not affect the sound, but I would worry more about making sure everything has sufficient ventilation for proper heat dissipation. You wouldn't think digital components generate much heat, but I recall my Oppo 205 running quite warm and I would hesitate to stack anything on top.
Stacking gear no more rack space does it affect sound quality
I've run out of room for my gear. Since I started streaming i have run out of rack space and began stacking. I bought some of those brass disc long ago for putting on top of components for damping and was told by seller not to use to many it will dull sound. Now I have my preamp power supply on top of preamp and dac power supply and dac on top of preamp power supply 3 high. Streamer on top of phono stage. I have another dac on top of streamer. I have 3 racks 2 shelves each between speakers, total six shelves. Do other people do this and does it affect sonics. I don't even have room to take things off to try without stacking, to much crap plugged in.