That, and all the other known stuff, and also someting I see mentioned few times: people's ears and pre-conceptions.
The shop I worked in was up-market. We once organised a day of listening, and twas done so the listeners didn't get to know which gear they heard (dark stage, thin veil between gear and audience - lit from audience's side). People started bickering as they all heard different, often opposed, things.
- "Way too scooped sound!"
- "You're crazy! Way too little bass and treble!"
- "Way to open! Tiring! It's that demn veil!"
- "Way too compressed! It's that demn veil!"
You get the drill.
Twas the last day I was a fanatic.
It's easy to point at a weakness the CS 505 has: it's harder to tweak than most more expensive decks. There's also the point that with a cheap Dual like that, there are more measurable differences between individual units. (We had a system for that, Ortofon perhaps, which tested the unit and printed a report.)
Point remains: Put an Ortofon MC30 on the Dual and also on an SME on the GyroDec, and, to our ears, one could live very happily with the modest Dual.
Oh, another story. We were to start selling Cabasse speakers. Listened to their most expensive model and were seriously underwhelmed. However, me listening concentrated, with closed eyes, I suddenly startled at a certain sound, and opened my eyes as I thought the importer was joking with us by playing a real instrument in the room. Of course the importer wasn't, and that "real instrument in the room" was actually the sound from those Cabasse speakers. Whoa!
Also, during the 1812 Overture, I was obviously sitting in the wrong chair:
the cannon shot right through my chest and I died on the spot.
That's Hi-Fi! 😉