Zeos for headphone amps and headphones, Steve Guttenberg for speakers, preamps, and power amps.
I have yet to find a reviewer who shares my preferences in what a DAC should sound like.
I rarely read reviews but I did read one after I had already purchased an amp, just to get someone else's take. I loved this paragraph...
"For me, choosing sides in the old tubes-vs–solid state debate is a Solomonic ordeal. I often love the
sound of tubes (in the right system), but that soothing, seductive signature is offset by the care and feeding that tube technology seems to require. Plug in a solid state amplifier and you're good to go, probably for decades. Plug in and turn on a tube amp and you've got
responsibilities. Depending on the particular model, you may have to make sure there's always a load on the terminals before plugging it in and remind yourself to adjust the bias from time to time (although PrimaLunas, admirably, are truly
autobiasing). You also can't help but listen for tubes that are possibly sputtering toward death. You'd best have spares on hand when they finally croak, and be prepared to spring for an entire fresh set every so often. Which, especially in times of tube scarcity—I'm looking at you, Russia—can tax budgets."
https://www.stereophile.com/content/primaluna-evo400-integrated-amplifier
I do not mind the responsibilities and I have several sets of extra tubes.
“It is the time you have wasted for your rose that makes your rose so important.”
― Antoine de Saint-Exupéry,
The Little Prince
As far as DAC’s I just listen and compare, I personally find it difficult to choose based on what others try to describe.