I've been saving up for a TOTL electrostatic headphone system mainly to afford a legitimate audition of various summit-fi estats so as to sate my curiosity.
Preamble (why I'm interested in estats):
In "short", I've heard exquisitely sharp transients (isolated with a
single-sample Dirac delta file) through the Arya Stealth at the expense of 4 kHz and top octave resonance issues (peaks move between reseatings, and sine sweep image wanders left and right through them), and through the Meze Elite Tungsten found with sine sweeps and pink noise that I could achieve a more consistently smooth target EQ with none of the aforementioned resonance issues, though both headphones exhibit what I believe to be an audible resonance spray consistent with
soundstagenetwork.com's CSD measurements, and if I am objectively not hearing the
duration of the decay, I am at least perceiving its compounded frequency content. Particularly when I auditioned the Meze Elite against the Focal Utopia, DCA Expanse, and shortly the Final Audio D8000 Pro and Sennheiser HD800 S, I found that the DCA Expanse and Final Audio seemed to produce the cleanest transient decays (produced through the aforementioned file), and with a salient decay frequency of a different pitch, though subjectively not as sharp as the Elite which I found to not be as sharp as the Arya perhaps due to its diaphragm not being as light, plus its measurable bass resonance; I may someday after FR matching with in-ear mics post about correlating subjective perceptions of transient sharpness and decay cleanness with measurements. (In practice, when EQed to a very similar frequency response, the differences between the Arya Stealth and Meze Elite are subtle, the Arya maybe being sharper at times, but the Elite's leather hybrid pads and lighter clamp sometimes imbuing preferable subjective qualities amid an otherwise very similar EQed tonality and presentation.) I drove these with my FiiO K9 Pro ESS which I would expect to perform a bit better than
the pre-production unit L7Audio measured, whereby high gain was needed for some of the transient tests (it impressively drives the DCA Expanse quite well over balanced outputs), though I can imagine that these transients were completely unrealistic for actual music; I wish to cherish this thing for life, but alas, after five months of enjoyment, I've had to send it in for electrical repairs and can only hope it last much longer after that.
I can already hear exquisite things out of my Arya Stealth, Meze Elite, and even my Bluetooth Jabra 85h Elite when EQed by ear to my same general target, my FiiO K9 Pro ESS surely not being a bottleneck, but I still wish to hear whether it is possible to achieve exquisitely incisive transients, but with a clean decay as well as a good control of resonances allowing for clean and consistent EQ maximizing theoretical transparency into recordings.
Findings:
It seems known that discounting audibility thresholds, it seems a shame that for supposedly such low-distortion high-end electrostatic headphones (in a few months, I will report on how well they take to EQ), available amps seem to barely meet the headphones' own performance, regardless of whether that matters. So far, I was first impressed with the HeadAmp Blue Hawaii SE's published THD, though it seems like a recent concerning figure was measured, evincing that their use of tubes may rather be of the "euphonic" than "tubes are great for high-voltage" sort--the Satin Grey version would have looked beautiful with the Stax SR-X9000, though, matching my Meze Elite Tungsten. I then learned of the Linear Tube Audio Z10e and was impressed by their
marketing material and that it could also drive my planar magnetics (so I could enjoy a short period of sighted A/Bing where I would most likely not hear a difference, mind have a use for the ONE Little Bear switchbox I preemptively bought), but it appears that SIY already found that their implementation is indeed a case of achieving exquisite
tonal transparency while failing to control distortion. Then I was rather excited to learn of the "too good to be true" Topping EHA5 that could save me a whole lot of money (and allow me to make my auditions and purchase in September instead of December), and with which I could happily drive an Audeze CRBN, HiFiMan Shangri-La Jr., or Stax SR-X9000 (the other contender is the Warwick Acoustics Bravura system which my local shop has on an attractive sale), but the findings on the
head-case thread are concerning, unless one can be assured that it is mainly practically irrelevant quibbles about square waves being fed bandwidths that you would not see out of a properly filtered DAC. bobkatz corroborated the 10 kHz square wave measurement, but I suppose regardless of that band limiting, if all the frequency components are actually as low distortion as Topping measured, then it literally doesn't matter, and per the DAC's and our own ears' band limiting should have no subjective advantage to the perception of transients.
Crux - what to send to Amir if anything at all:
Now, after a somewhat grueling search, I finally found
https://www.stereophile.com/content/katzs-corner-episode-21-how-insensitive-part-3 featuring Bob Katz rather nice measurements of the Mjolnir Audio KGSSHV Carbon which finally contented me that Mjolnir Audio's implementations of Kevin Gilmore's designs are indeed trustworthy for objective performance insofar as one lacks the means to go the DIY route, or doesn't trust JR Audio (I have yet to learn who else sells implementations of KG's designs). Perhaps not as low distortion as the EHA-5, but those square waves look impressive, and perhaps the 10 kHz square wave shown suggests that amp's not being as band limited as the EHA-5 (looks like around 40 kHz instead of 20 kHz Gibbs oscillations), though as mentioned, that may not matter. Its THD+N versus frequency is also impressively flat through the entire audio band; the EHA-5 starts with higher bass distortion (supposedly due to the transformer design), but fortunately having the most distortion where as far as I know it should be the least audible, and the least distortion within the midrange, ear gain region, and treble.
Given this, I'd like your input on whether for my goals for audio transparency, it would be reasonable for me to settle with the Mjolnir Audio Carbon CC (purely for the giddy and embarrassed enjoyment of "audio jewelry") with the intent of sending it (and also the estat headphone I settled on) straight to Amir first for measurement using all the advice we have accumulated so far. Otherwise, I might just start with the EHA-5 (a small dent in my saving budget and rate for what will probably be my last high-end headphone and gear purchase for a long time; speakers come next once I finally get my own home office) and see if it contents me. I might also send the EHA-5 straight to Amir first and perhaps get folks riled up if it measurably drives the SR-X9000 or something excellently. My only concern is whether I being in Canada would have to pay customs charges twice...