I read five reviews of the Benchmark L4. Uniformly, the reviewers found the pre amp extraordinary in revealing musical and acoustic detail, without any affectation or distortion, in a finely constructed piece of equipment. Clean and clear was the universal opinion.
It is on ASR, Matt Hooper's review of it and the Conrad Johnson pre-amp Blind Test Results: Benchmark LA4 vs Conrad Johnson Tube Preamp | Audio Science Review (ASR) Forum that I find myself very interested in his keen observations (I used his quote in italics). The four pages of mostly his observations indicate that despite the super detail, dynamic range and open bandwidth without any negative as to its operation, it is not his favorite to listen to most music and he prefers his Conrad Johnson, with all it's distortion and alterations of the sound. He prefers a sound with more body and warmth. Well I prefer my subminiature tube/voltage regulated design pre-amp and I don't prefer the CJ pre-amps or amps I've heard (plenty). My pre-amp sounds more like an Audio Research SP28 WITH different tubes (6N6 or 6N6). The stock tubes/unit as is just thin sounding and lacking in the body and warmth department. I bet it measures better than the CJ and certainly is a more open sound. With the change in tubes, wow, a totally different pre-amp.
I don't know what is inside of the Benchmark but is reportedly of professional audio quality parts per reviewers. It may be possible to elevate this to a status which incorporates more body and warmth without losing any of its' measured superior qualities, openness, details and extension. Changing some caps, regulators and/or resistors. Or possibly it can't be done and it remains as a finished product with a particular clean, clear sound that is less attractive than other high end pre-amps that may not measure as perfectly.
So, score 1 for Mr. Hooper whereby he prefers a lesser measuring pre-amp buts enjoys both.
On the last page, he mentions his love of vinyl. Score 2 for Mr. Hopper. Immediately, he is warned by a donor member that ASR frowns upon discussion of vinyl records. Mr. Hooper understands and obliges without pressing the issue. That's probably why he is still an active member. Can you imagine if Audiogon members said don't discuss vinyl as a warning, such as that could get one banned from the site? That's why ASR is so narrow minded. Don't mention an inferior music delivery format and be careful in your preference for an inferior measuring piece of equipment. Like there is something amiss not preferring the perfect measuring equipment. That's where most of the posters here at Audiogon recognize that maybe there are other elements of sound reproduction that are preferred to measured perfection, that are imperfect in some ways.