its got to do with the voltage output... I believe the current standard is 1.1 to 1.5 volt? However, many of the more mainstream and even higher end units might give you 1.8 to 2.5 volts.. Your marantz might be 2 volt which was not that uncommon. Shanling is probably attacking a little higher end Amplifier market and more efficient systems, for example I have a 101 db speaker and it would get a little annoying not being able to turn up my system with the wrong digital glare occuring with a high output player, and then not being able to put up the preamp to get some of the sweetness out of the pre, the CD then becomes too forward sounding if its too high of output.