In the 1980’s when I was getting into high end audio I swapped preamps looking for a good sounding preamp. After half a dozen failed attempts I bought my first (used) Audio Research preamp. My swapping immediately ended. I had that preamp for fifteen years. A few years later adding an Audio Research phonostage. I have researched and upgraded my system many times and piece by piece ended up with more Audio Research components. Once, I put one in, it stays, except to upgrade to a higher tier.
Audio Research from the beginning has focused on natural musical sound with detail… hence the words high definition written on their components. But unlike many brands that have lost the music in pursuit of detail and slam ARC has carefully walked down the knife edge, not losing the musical core while increasing resolution and black backgrounds. They are built like tanks with intended lifetimes in the decades.
All of my main system is now Audio Research. Highly recommended.
Do not waste your time on ASR. The site focuses on graphs and chart of parameters that obfuscate what components actually sound like to the human ear. The site will point you in the wrong direction if you want high quality sound.
Look at used Audio Research LS or REF series preamps, as contemporary as you can afford. You can see my systems under my User ID.