"They" are not always right!
How can you judge the source if you can't hear it? If you get the speaker/room/amplifier thing right, then you are in a good position to make judgement calls on the preamp, source, cables and other tweaks.
How can you judge the source if you can't hear it? If you get the speaker/room/amplifier thing right, then you are in a good position to make judgement calls on the preamp, source, cables and other tweaks.