How do you know when a stereo sounds good?

You are sonicaly in pursuit of the  "EARGASM"  and like all other 'gasms' it is totally a personal and internal even.  Think of it as a light hallucination of joy that usually brings forth pleasant memories, or something that.  Beyond this there are no other criteria because only you - are you.

This is an interesting question - I can relate. A few years ago I was wondering the same thing. My system sounded really good (it sounds even better now) and I wondered if it sounded so good because I hadn’t heard anything else for quite a while. Every upgrade had raised the SQ but I had no idea how it compared to other systems.

My answer to this dilemma was to go the AXPONA in 2018. I treated myself to an indulgent audio vacation and I was on a mission to broaden my perspective. Bottom line - I was very pleasantly surprised. My system sounded as good as at least 90% of the systems I heard at the show. Many systems had cabling that cost more than my entire system along with very expensive speakers and exotic components. I heard several systems that cost in the low to mid six figures that flat out sounded worse to my ears than my mid 90’s vintage Krell and Thiel setup. They didn’t sound as natural, they didn’t image as well, and there was nothing that made me think "Wow."

Yes, I know that show conditions are not the best way to judge audio SQ but I also heard several systems that gave me something to aspire to. MBL 101 Mk II, large YG’s (I don’t remember which model), Borreson, Von Schweikert Ultra 11’s, and a few others presented sound that I would love to have if I could afford it. I also heard some very expensive speakers by Wilson and was shocked at how much I didn’t like the sound. I heard other people rave about them which proved to me that my system is giving me the type of sound that I prefer.

I’m very comfortable that my system is somewhere in the ballpark of Class A as defined by Stereophile. I sit and listen and often smile and shake my head because it sounds so good. I will still upgrade and continue to tweak but I’m convinced that my system sounds as good as I think it does.

When a system has the ability to electronically resurrect dead musicians & they are in the room with you. 

When presented with a proposition that is demonstrably false, I’m probably obtuse as well.

As @roxy54 noted, this self-awareness factoid - despite being a falsity in itself and a convenient deflection by the OP - does not address the primary and fundamental error and is completely irrelevant and/or has no meaning in the context..

It seems that I am in the minority of people who recognise speech that is intended to persuade but has little regard for truth.

I know it’s good when I have to switch one of these in for extra long listening sessions. (Pic of toilet seat)

@dekay  Me too. When having a restroom break is the last thing you want to do.