As my systems became more finely tuned over the years, I began to notice that recordings I remembered as all sounding reasonably good differentiated into a large group of recordings that sounded spectacularly good, and a small group that didn't sound anywhere near as good. What I also observed was that if I put together two equally good sounding systems from different components, the same recording could sound wonderful on one system and ho-hum on the other. It wasn't the recording. At this point, I could have done one of three things: One, dial the system back until all recordings sound just ok. Two, live with the tuned in system that does most recordings extremely well and ignore the recordings that aren't so great. Or three, tune the system to the recording.
I'd like to say that I've been in camp number three all along, but that isn't true. Opening a system up by stripping down components, using good platforms and good wire, careful setup of speakers and room treatments, and releasing tension from the electrical will get you to spectacularly good sound. But tuning to the recording is really a different skillset. It's the same tools and techniques, but you need to understand what sonic effect each move has and then put together the right combination to get yourself where you want to go. With so many variables involved, it was really more than I felt I could do.
What changed things for me was the discovery of the Audolici A25M. The Audolici is an integrated EL34 tube amp that makes about 30W per channel. It's a lovely sounding amplifier even untuned, but what really sets it apart is its ability to be tuned to the recording with wooden blocks under its chassis. What this means is that recordings that had sounded distant, unfocused and uninvolving can be tweaked into sounding beautiful in just a few minutes. And the spectacular recordings sound just as spectacular as ever, with their own settings. Essentially, what had been a complex process involving many different parts is now reduced to an adjustment on a single component.
In practice, I find I don't actually need to retune for every CD I put on. Many recordings will sound at least good to very good with the same block setting under the amp. But when I put on something that has a distinctly different recorded 'key', I'll know it inside of 10 seconds, and I adjust the blocks until I get the sound I know was in there. :)
I know there will be people who read this and have no interest in going down this road. Believe me, there's no judgement. Every person needs to decide for themselves what great sound is, and how far they're willing to go to get it. I'm just telling you about what has worked for me.