In my experience it depends.
For example, the Pass Labs preamps and amps sound better with XLRs. Also, using XLRs with these components diminishes the audible difference between cables. I have experienced the same with Audio Research LS and Ref series preamps, as well as ARC CD players. With my Benchmark DAC3 HGC in my system I prefer single ended to preamp. I run a 15ft long Mogami Studio Gold XLR between Pass XP-12 preamp and XA-30.8 amp that powers my Wilson Sabrina. I compared it to my 1m Acoustic Zen Absolute Copper and yes there’s a slight difference but the AZs aren’t necessarily better and the difference in this case isn’t drastic.
Now I also had single ended Acoustic Zen interconnects and each step up the line brought a pretty significant improvement. There’s no substitute for trying though.
