I have no particular agenda about Esoteric, but your statement at the beginning, about judging an integrated amp by the way it drives headphones, is frankly a head scratcher. As mentioned above many manufacturers supply a headphone jack without tuning their equipment for the special needs of headphones. In general you will do much better with a dedicated headphone amp, especially with the much more demanding headphones that have come out the last decade or so.
I heard a costly system from Esoteric.
2 days ago I was able to audition an Esoteric audio system. It consisted of the following:
Esoteric F-05 (Class A/B) integrated amplifier
Esoteric K-03 - CD/SACD Player
Over the years, I’ve been a vintage audio guy and I’m also into headphones. Someone told me that listening to an integrated amp with headphones (6.3mm) will give you an idea about how sound quality from the amp translates over speakers. I’ve found this to be very true in practice.
I gave it a go - with the NAD HP50, KEF M500, and some other (more) high-end headphones the store had. Currently, I only have the NAD’s and KEF’s, but I’ve owned dozens of high-end headphones in the past. Unfortunately, I was very disappointed. Please allow me to explain without calling me a liar. It’s nothing personal, just my impressions!
There was considerably less drive/power behind the headphones. For instance, you would literally feel the bouncing air on the cups on closed-back headphones. Literally the same as a headphone dongle with a small amount (in mW of output power). In each song I listened to, I heard familiar details, but it was glossed over by a very sharp and peaky midrange and treble. There was clearly a boost in these frequencies. Bass was anemic. Normally, with high-power headphone amps and even some vintage integrated amps (high-end back in the 90s with 0.09 or less THD etc.), I got the detail with the sonic finesse. In other words, everything the Esoteric amp and CD player did together, I’ve already heard before. It simply pushed mid-treble frequencies to the forefront.
And the cost for this system? 13 Grand for the CD Player. And at least 10 Grand or slightly more for the amp. So 23 grand or slightly more with taxes factored in.
For this kind of money, if they are including a 6.3mm port for headphone listening, shouldn’t it be optimized? Afterall, if you’re going to include that in an amp, make sure it sounds good! I’ve heard headphone systems costing much, much, much, less that sounded better.
My last disappointment was the CD skip - track seeking function. It was very slow. Even some vintage CD players had a skip function where you hold down the track change/skip button and the numbers move like a stopwatch. On the K-03, it was by the second, or a few seconds at a time. And I had to press the play button again, rather than simply seeking the part of the song I want to listen to.
Source: high-quality CD’s that I burned with .wav files (familiar songs, and original CD’s from my CD collection)
Don’t get upset, Esoteric owners. Feel free to share your impressions without getting mad at me. I know this is a touchy subject; since the object of one’s desire (especially after spending this much money) should be justified!