They say that with the Sundara as well. Technically they are not wrong Sundara was a glue swap not a driver change so only 1 Version, Then came what is clearly a pad swap so they still say "technically" 1 version.
The amp I started with was the FX Audio DAC X6 mkii, a cheap but still decent DAC/amp combo unit. It has power spec'd at 940mW @ 16r, 900mW @ 32r, 450mW @ 120r, and 200mW @ 300r. It was good for a set of $28 Monoprice HiFI DJ cans that I bought when I was first starting to build a HP setup. But when I got a set of Hifiman/Drop he4xx planars it struggled and I never felt that I was getting the best out of them. It got sorta loud but I had absolutely no headroom, needed to turn it up to btw 3pm 4pm on the volume dial. I knew it wouldn't drive the next set of planars I was planning on buying - Fostex t50rp mkiii's. The DAC X6 is over 3 times more powerful than your current amp, for comparison.
That's a weird experience, considering you need 160mW for 115dB peak SPL for the HE4XX at 93dB/mW at 35Ohms. As you said, planars probably need more current, but what's the point if you just lower the volume on the more powerful amp?
Planars will suck up an amp's power in form of current, which takes a good power supply and output stage. Won't have to turn it down like dynamic HPs, but may need to turn it higher to provide a more constant current for a planar. Hard to explain it to those experienced with only dynamic cans (such as my former self) but once you get a planar, you'll be able to see for yourself if your amp is up to the task. I had to see for myself bc I didn't really believe it either. If your sound is either low volume, thin sounding, or raggedy and uncontrolled sounding when you wanna turn it up you probably need a more powerful amp.
There's no inherent quality that puts one technology over another. One thing that many planars do better than many dynamics and even many electrostatics is deep, detailed, and well defined bass. The Aryas have deep bass that plays below 20hz (mine can play ~15hz) with virtually no or very little roll off, whereas most dynamics have a hump around the midbass and fall off well before they get to 20hz. Dynamics also have much more distortion in the lows. Planars are sometimes called fast, meaning that they respond more quickly to a musical signal and that can sound very pleasing and have much less distortion. Many planars need beefier amps than dynamics to play those deep bass frequencies and stay controlled though.
The new stealth magnets revision.
I am in an exact situation. I bought a pair of Arya v2 (used) last week. Upon arrival I notice some damage on top of the yokes so I contacted Hifiman for a replacement headband. I was offered to send in old Arya + cash for a new pair. To me this is very anti-consumer. The Arya they took in can be easily sold as b-stock.
