Living Thoughts: Audio gear and “audiophilia”
DACs are a nearly-100% solved problem. If you feel you need one at all (read: you can’t trust the line out of your computer to be clean, you aren’t going to use an all-in-one like a dongle of some sort, or you need various features available only through standalone implementations), get something that measures decently with good build quality and the features you require (be that DSP/EQ, Bluetooth, eccentric inputs, etc.) and be done with it. Do a quick check before purchase to make sure it doesn’t measure absolutely horribly: almost nothing on the market at this point is going to be objectively horrible, but gear from before about 2018 (when the industry got somewhat forced to pay attention to objective, scientific measurements) varies wildly.
Headphone amps are “somewhat solved”. It’s possible to objectively measure whether an amp is going to color the sound, or be transparent (peruse Audio Science Review, /r/headphones, or sometimes Super Best Audio Friends for these measurements).
For most purposes, coloration of sound is generally bad: tube amps, where coloration is intentional, may be an exception, though I generally hold that any desired coloration added by tubes is done better, cheaper, and with less energy demand and component wear via DSP at the DAC or source stage.
An amp either can provide enough power to evenly amplify the entire frequency spectrum for the given drivers, or it can’t: exclamations like “this amp lifted the veil!” from an audiophile are to be assumed to be bullshit until proven that (1) the listener has ABX tested, preferably blindly with the help of a friend, the two amps in the same listening environment, (2) such ABX testing was done with matched volumes within 0.1dB, and (3) both amps meet the power demand specifications for the headphones used for testing. Many “audiophiles” are allergic to ABX testing (and one famous audiophile forum, Head-Fi, outright bans discussion of ABX testing), so this may be a tricky set of parameters to meet.
Get something that is reasonably transparent, has inputs compatible with your DAC’s outputs (not applicable for all-in-one units), has good ergonomics (eg. the volume knob feels good in your hand), has little or no channel imbalance at reasonable listening volumes (digital/relay volume control is great for this, but hard to find in desktop amps), and has a reputation for reliability. It’s possible to DIY an amp with all of these traits if you’re so inclined.
Bonus thoughts: “balanced” is mostly marketing bullshit for the overwhelming majority of common headphones. When tons of power is necessary (which is already rare), it’s entirely possible to push a boatload of power through a single-ended ¼” jack, see for example JDS Labs Element III Mk2 “Boosted”. That said, for demanding cans, balanced (over XLR or 4.4mm Pentaconn) connections can be useful, assuming the output signal is truly balanced (each channel gets its own amp, and there is no shared ground), to make up for otherwise-underpowered amp implementations. For example, running planar magnetic over-ear/full-size headphones off of a dongle DAC is going to be extremely tricky single-ended, but over a truly-balanced 4.4mm Pentaconn connection, cans like Hifiman Arya and Dan Clark Aeon stand a better fighting chance of being powered cleanly.
Cables are mostly for aesthetics and ergonomics. Get something that looks and feels nice and move on with life. You may, or may not, hear small differences in sound between cables of different materials or gauges. You probably won’t, and if you do, it probably won’t be earth shattering. I’ve heard exactly one cable, ever, anywhere, that had any noticeable impact on sound quality, and it happened to be the only non-copper cable in the room at the time.
(Stock cables that come with headphones are often garbage: again, not for sound quality, but for feel, or length, or repairability).
Considerations beyond the sound
Comfort, build quality, quality control, reliability, and repairability are all traits to consider before ever getting into how a headphone sounds. Some of the commonly-considered “best sounding headphones” are frequently plagued with faulty (or DOA) drivers, snapping headbands, channel imbalance, fidgety-at-best ports and plugs (or worse: captive cables), or, most egregiously for something that has to be worn on the head for, presumably, up to hours at a time, are grossly uncomfortable.
Brands that do well by these metrics include Sennheiser, Meze, Audio-Technica, Sony, and ZMF. There are Sennheiser HD600s from the 90s still kicking to this day, and HD565s from even earlier. They’re also notoriously lightweight and generally comfortable for extended listening. ZMF headphones generally come with a lifetime driver warranty. Sony headphones get tossed around countless recording studios and DJ sets and still last decades. My own set of Audio-Technica M50Xes I bought in 2015, now mostly a travel and music production headphone for me, have survived countless subway and plane commutes over the past nearly-decade, and even a few months being buried under a fire extinguisher in the back of my car (I’m not kidding).
Brands that do noteworthily badly by these metrics to varying degrees include Hifiman, Focal, and Audeze. Hifiman’s quality control woes are so extensively well-documented it would be exhausting to recount it all here, but all the way up to their $6000 MSRP flagship model, driver imbalances, assembly malfunctions, or failures within two years of varying sorts, are all rampant. Focal headphones are notorious for headbands snapping, and for replacement parts being either impossible to source, or nightmarishly expensive (pads are especially noteworthy here, at $200/pair at time of writing for Focal Clear pads). Audeze cans are frequently plagued by drivers that are either dead on arrival, or dead within a few months or a year of use - I myself received some “certified B-stock” Euclid IEMs which were DOA. Further, Audeze’s headphones are notoriously heavy: try before you buy, unless you frequent the gym for neck-specific exercises (or grew up playing saxophones, like I did…).
Bonus thoughts: In general, while planar magnetic drivers have some truly impressive technical merits and sound qualities (I’ve owned some headphones with these drivers, even!), they seem to score quite badly in reliability. While I trust a Sennheiser or ZMF dynamic driver to last years-to-decades, I have rather little trust in a planar magnetic to last more than about 5-10 years unless coddled. Consider your lifestyle and listening environments carefully before purchasing headphones with such a driver, which includes most, though not all, headphones by Hifiman or Dan Clark Audio, some by Meze, and as far as I’m aware, all headphones by Audeze or Rosson at time of writing.
About price, or about the industry in general
I almost considered putting this block at the top of the page, but I think it serves better as a closing remark.
At the end of the day, keep in mind that “audiophilia” is an industry fueled by consumerism. I once heard it referred to as “shopping addiction for those whose finds of choice happen to produce sound”, which honestly doesn’t seem far off. If enough folks are willing to buy $2000+ headphones or amplifiers on every yearly or two-yearly release cycle, the market will produce such gear on such a cycle at such prices, and laugh their way to the bank about it. If enough folks are willing to think they don’t have the absolute greatest possible experience, companies will happily continue to churn out gear, at ever-more-comical prices, to appease those folks (“chasing the dragon”, as it were).
Beware anyone who uses price as their primary basis of comparison between gear, or as grounds for not considering various gear comparable. “Well of course this $250 amplifier can’t be expected to compete with this $2500 amplifier” is a refrain frequently found on audio forums, especially from folks who have that expensive gear. Sure, there can be technical improvements in the more expensive gear, but there can also be significant sunken cost self-validation in those words.
Further beware companies who seemingly never have a shortage of new models to sell you. Contrast, for example, the tactics of companies such as Sennheiser, who releases a new HD-series headphone every several years, often with drastic differences, against those of companies like ZMF, who release new models, albeit generally significantly differentiated, yearly or more, and yet again against those of companies like Hifiman, who have so many product lines and revisions (some silent) within those lines that there’s chaotic unofficial version numbers within the used market (“4-screw version”, “6-screw version”, “v2/v3/2020 Edition/etc.”).
(more on this later… I still need to dig into the COMICAL ABSURDITY that is the delineation between “low-fi”, “mid-fi”, “hi-fi”, and “summit-fi” in the audiophile scene, and the arbitrary, consumerism-driven delineations between those brackets defined almost solely by price, feeding a “chase the dragon” habit in the scene…)