I am a advocate of Comparisons, keeping this to a DAC only, I have had a short period of comparisons between Tubes and Filter Combinations available to be used on a Bespoke Built Valve DAC.
This same DAC has been compared to other DAC's prior to and following the Tube>Filter permutations investigations that can be used.
I like myself have selected non- designer/builder selected Tubes, and have chosen measured and very accurately matched early 60's Tubes.
The Plug In Filter options supplied by the designer / builder, even though looking quite robust a design, do have a substantial impact on the coherence across the Frequency range.
I can have, 1, Lean Sound (for a valve design), 2, Richness of Tone (underpinning the notes vocal with a little weight), 3, Richness of Tone (that much favours the Bass, quite a weighty underpinning). Options 1 or 2 are the most preferred to date by all who have experienced the options.
I do believe, it is not possible to accurately remember sound produced by other devices after a period of separation, even in my case a short period of separation. I do feel confident in saying the recollection of a stimulus made on myself as a result of experiencing an audio device is what is the most memorable. In my case the idea of adding value or taking value away as a result of a stimulus created, is very subjective and isolated to my own perceptions of sound how I am stimulated by being exposed to it.
I have for many many years been arrived at the place, where having a personal experience, or encouraging other to do the same, is always a much much important method to be adopted, than limiting oneself through evaluating using the descriptions offered up by another, this might be the best if kept for considering items to be put on to a shortlist of products to become further investigated.