What are your Eureka Moments in this Hobby?

@peter_s  Yeah, being a seasoned citizen, I began with a JVC integrated and later, Phase Linear 400's.  The Aragon came later. 

Speakers were ESS Heil AMT3's and later, Martin Logan's and then the Apogee Stages and finally SoundLab (full range esl's, 3-different models). 

CD players were Magnavox, Meridian, 2-Wadia's and PC DAC's beginning in 2006: have been 2-Wavelength Audio's, 2-Lampizator's, a dCS and now an EMM Labs DV2. 

Along the way, reel-to-reels were Tandberg and Revox, with a Pioneer Tuner thrown in the mix, which is still operational.  And turntables were a Dual 1229, 2-Thorens and lastly, a Galibier Quatro with a Tri-Planar tonearm. 

So, along with the amplifier eureka moment that I mentioned, there have been several more.  Not the least of which was switching from a Mark Levinson 336 amp to CAT JL1's.  During that audition, a eureka moment was an under statement.  With my Soundlabs, the 100-Watt CAT's trounced the 350-Watt Levinson in every area, along with Parasound Halos I trialed simultaneously with the CAT's (vs the Levinson).  Neither the Levinson or Parasounds were bad, quite the contrary; but the CAT's were that much better (again, with the SoundLabs).  The Atma-Sphere MA-1's and Pass Labs X600.8 are about as good as I can imagine with my present 8' SoundLab Majestic 845PX's.

Lastly, I agree, the Aragon 4004 MKII for its price point, was/is indeed a superb amplifier.  My son still uses it in a 2nd. system, because he has very high efficient speakers.    

And don't get me started on HT surround sound.  I began with a Lexicon MC1 and my old ESS Heil AMT'3.  Now, I'm using a Marantz pre-pro and 5-Martin Logan floor standers (& 2 in the ceiling) in one room and in the 135" other HT room, there is a JBL pre-pro, an 11-channel Monolith amp and 13-Klipsch speakers.  BTW, and as an aside, for HT and their price points, Klipsch speakers are hard to beat. I've found the center speaker to be one of the most important, and the Klipsch sound provides a crisp and clear midrange for the center. 

Hearing the Quad 57’s/Futterman H3aa’s OTL monos/Marantz 7 tube preamp at Doug Kesara’s house in Harrison NY in  1978! Phono cartridge was a Panasonic strain gauge. Turntable was a Thorens TD125.  After listening to this system I was determined to acquire a similar setup! Decades later I have!

@peter_s 

No conspicuous omission on my part, but I probably didn't express myself clearly enough.

Let’s imagine three people:

One connects to technical performance in their system — they have a connection to sound. I’m emphatically NOT claiming that "listening to music" is somehow superior to listening to sound. Why would anyone judge what someone does for pleasure? If someone gets deep satisfaction from the technical challenge of optimizing a system sonically — that’s entirely legitimate. I have no interest in policing motivations.

The second person loves music and wants a good system to deliver it. They want to forget about the means (technology) and just enjoy the end (music) as soon as they can. Again, no judgment. People love what they love, and if they prefer to separate means from ends, that’s their preference.

The third person has no connection to music or sound; they’re not engaged in a listening activity at all. They’re doing something else: collecting, status-signaling, engineering appreciation. I don’t judge this either, but they’ve exited the category of audiophile listening.

Your objection uses the third person — someone who isn’t listening at all — as evidence that "listening to sound" and "listening to music" are opposed activities. But this conflates two distinct types: the first person (an audiophile focused on sound) with the third person (not an audiophile at all). Those are different categories.

My point is subtler. When I’m actually listening, the supposed opposition between attending to acoustic properties and attending to music is false. I cannot attend carefully to musical meaning without attending — maybe not focally, but to some degree — to the acoustic phenomena that constitute it. 

When I listen, sometimes the music is the focus and sometimes it’s the sound, but both are always there. The ability to control what is focal is an achievement of listening practice. The inability to control that is a kind of dysfunction that I often see audiophiles complain about.

@lewl28 +1 on that feeling. I'm content, happy and for now, solidly off the upgrade wheel. I've found my lane. 

@hilde45 I think it is true that you did not explain your insight clearly. In your original post, you discussed a false dichotomy between the music and the sound elements. Your post expressed that false dichotomy as a general truth, but in fact, it is a truth for you. Your second post illustrates that dichotomy as a real (true) one, and in fact adds another endpoint. I think what you’ve written about your own realization makes a ton of sense, and I agree with it. But it seemed to be expressed as a general truth, whereas in fact, it’s a personal truth. And I do agree, that all three endpoints of enjoyment can be expressions of defensible motivations!