Background I knew Yamaha’s vintage models were frequently mentioned and loved by vintage ortho fans, but when I could borrow an actual pair from @Philimon, my expectation was far from being high. How can I have a hope for the combination of small drivers (for ortho), supra-aural drivers, and small closed-back enclosure? The list of such keywords sounds like a huge acoustic disadvantage. Well, I wasn’t 100% wrong. What I didn’t expect, however, was I ended up getting my own pair. OMG. Subjective Evaluation Before jumping into my thoughts, let me explain a little bit about my on-ear headphones history. I don’t think I have much experience with this type of headphones. Many years ago, I happened to hear B&W P5 and Beats Solo2, and liked them both. Grado couldn’t impress me but cut through via F-cushion equipped Hemp. For a stable daily driver, however, the former group lacks technicality while the latter was painful in ergonomics. So, that’s where I started my time with Yamaha’s vintage on-ear headphones. What did I find out? In short, they fit very well with my day to day life needs. Summary of specific thoughts below. All the evaluation was done via Soekris DAC 2541 and its builtin headphone out. What I like They’re comfortable. At 275g in my scale, they were not particularly lightweight for on-ear headphones (orthos can’t beat dynamic headphones in weight for the same sonic performance). But, Yamaha put a lot of thought into designing straps, clamping elastics, and ear pads. All these components combined with the sub-300g weight simply nailed it in the ergonomics game. I could literally wear them for the entire 8 hours during a work day without being bothered. I was very surprised at this point as all the other vintage orthos I tried were (albeit with some impressive sonic merits) shitty in ergonomics and did not consider human comfort at all. HP-1A comes with non-aggressive tone balance. They can render vocal sound moderately meaty and wet with good presence/sharpness. While they’re a little mid-centric sounding, fatiguing points were very well controlled without disjoint or disconnection across the spectrum. My limited experience of vintage headphones was most of them hardly obtained acceptable tonality in stock. Honestly, HP-1A is too well-balanced for me to hastily desire additional mods. Another sonically surprising point was their ability to portray space. I don’t usually expect too much of this for small drivers, but when I threw in Abyss dummy-head test recordings, they could discern extremely well between 6ft-9ft distances in staging. Also excelled in imaging accuracy between 0-45-90 degrees. Maybe a little exaggerated than actual distance/angle, but note that such exaggeration is clearly associated with better spatial feeling in playing non-binaural tracks via headphones. What I don’t like I have been consistently bothered by the annoying sound in two different sites. One place was diaphragm. It does sound like being crumpled or wrinkled whenever I push ear cups inward. Audeze LCDs with legacy air-tight ear pads had this character, but to less extent. Another annoyance comes from plastic disjoints that connect ear cups to headbands. Seems some plastic parts in the cup scratch each other and generate uncomfortable noise. This occurs when I reposition them on my head. Not a serious deal breaker, but something I want to fix asap. Bass extension is limited. For small drivers, it might be an acceptable shortcoming. But I found anything below 50hz was quite muted. I should only depend on the recorded harmonics when I hear low frequency instruments. Fortunately Yamaha didn’t take the upper-bass boosting approach, which makes HP-1 lows clean and not bleed into midrange. I have three vintage orthos in the house right now. HP-1 is the least technically capable among the three. Small drivers in small cups always have this disadvantage. Not surprising. Comparisons and other thoughts My modded HD6XX was warmer and airier. Not to mention comes with better details and dynamics. But I prefer HP-1A’s cleaner, less-congested, and less-veiled presentation in most of my favorite tracks. HP-1A also portrays larger stages with more believable imaging placements by comparison. Interestingly even with closed-back housing, HP-1A was more open sounding than the modded RP18/T30. But except for a few sonic criteria, those larger cup orthos resolve detail and dynamics more effortlessly. Subtle vocal nuance and techniques were better heard with the latter group by comparison.. If I recall correctly, HP-1A is technically far superior to B&W P5 and Beats Solo2 in any metrics. Also it must favorably rival the Hemp. I want to make it clear that all the advantages I described above were quite irreplaceable with any on-ear headphones I’ve ever heard.