OK, after spending a good few days with the EL32's here's my take. And as a pre-disclaimer these are my personal opinions, and YMMV depending on tube condition and other elements of your chain, or preferences. The below is based on multiple critical listening sessions well after my hearing has recovered over the last 5 or so days, and with an assortment of headphones; Senn. HD-600 with silver cable
(which I do find resolving and suitable for my tastes), Senn. HD-650 and Senn. HD-380 closed-backs, as well as a variety of well mastered songs that I'm intimately familiar with.
In a nutshell the EL32 are like a mini-EL12 Spez of a different flavor. Having only considered
sonic similarities until the time of writing, it becomes ironic noting how similar the (ST-shaped) EL32's look to the EL12 Spez
visually; yet are around 40% smaller. The EL32's to me have a dazzling sense of fidelity in a very sweet, detailed way, with bass definition / quality, detail and dynamics that are nearly impeccable. The highs are silky smooth and 'sweet', allowing for a fairly non-fatiguing listen at medium-high levels just as H1 put it. For me the DOWNSIDES lie in bass quantity (amount), 'thinness', and soundstage. My multiple comparisons against the EL12 Spez reveals a sound that to me seems more 'intimate' with a subtle improvement in texture and a slight boost in weight to the bass, as well as a substantially larger soundstage which to me was lacking on the EL32's. However the EL32's to me still have their place: a slightly more neutral, less euphonic tone can actually be a very welcome trade off for some recordings - which to me the EL32's certainly excel in neutrality with nothing overdone and not overtly euphonic. OTOH I do often prefer the EL12 Spez which to me is a master at uncanny reproduction of micro-detail, intimate voicing, texture, soundstage and a fairly pure bass reproduction.
Having also compared the EL32 to many other tube types I would say they sound most similar to VT-96 and Ken-Rad VT-231 (6SN7) in tonality, similar to EL12 Spez in frequency, but comparatively brighter than more neutral tubes such as GE 6SN7GTA, Valvo EL12, Bendix 6080, etc. (having also compared these as powers or as drivers accordingly). Speaking of
PAIRINGS: There's a reason why this article only pertains the EL32 pairings with other EL tubes: In agreement with H1, these do synergize better with EL tubes. My sole exception was as previously noted: EL32 (powers) + VT-96 black metal drivers. This pairing was robust, weighty, extended great PRaT; albeit
slightly V-shaped and not nearly as detailed / organic sounding as the EL32 was with other EL tubes especially all types of EL12 and the better pairing EL12 Spez. That is to say, IME the EL32's as powers don't like the 6SN7 class drivers, usually sounding 'soft' and not detailed, and make the miniature 9-pin octals sound bright; as drivers the EL32's don't seem to like any 6080 or 6AS7G class tubes; Bendix 6080 sounded 'good' but not nearly as synergestic as with other EL tubes, and somehow the synergy just wasn't there with GEC 6AS7G or RCA 6080's.
By no means am I advising against the EL32, as these do occupy a throne extremely high 'above the clouds' in the realm of super top-tier rare radio valves. To me though it takes a certain taste to like these, as they seem
modestly skewed toward the thin and bright side of the spectrum; almost as if a tube with the sound signature of the Beyerdynamic T1 headphones. Interestingly these are reported to pair well together as well; and I will once again emphasize that YMMV depending on your environment and preferences. Thus being said however, I would strongly advise AGAINST getting these tubes for anybody who considers themselves a basshead - the bass quality is fantastic but not especially forward.
So my advise is for anybody with a single-tube setup to get one pair of ST-shaped EL32's and one pair of EL12 Spez (each needing special adapters). The above was based on how these two performed
against each other (tested as both powers and drivers, which they both do with immaculate finesse and flexibility!!) Having also tested these
together, it becomes evident that that synergy abounds - BIG TIME! With EL12 Spez as powers and EL32 as drivers I get a very balanced, snappy and resolving sound, then reversing it with EL32 as powers it seems you get a sound that interestingly has a nuance more warmth and laid back. I would also advise anybody who's impressed with the sound of the EL32's to do a comparison with EL12 Spez whereas I feel confident that not only will you hear differences, but that 'that mighty EL12 Spez' will hold its' ground till the bitter end!!