I wonder how much the whole planar needs ss and dynamics need tubes is a myth.
In my experience, the majority of different headphones I’ve been able to hear on good tube amps, have sounded better on tubes. I found both dynamics and planars to benefit a fairly equal amount from tubes.
The main obstacle is that planars usually have a low nominal impedance and/or low sensitivity, while most OTL tube amps have a fairly high output impedance. Those high-OI OTLs generally don’t pair well with low impedance headphones because they’ll be underdamped too much to the point where things start to act funky. Underdamping causes an increase in demand for current, which in addition to the high current demand of many planars means they’ll not be able to pull enough current from the amp to maintain a sufficiently powerful signal. One of the most obvious things that start to occur is the bass will get flabby, like a car engine stuttering on its last few drops of fuel.
So to avoid all that good stuff from happening, you need a tube amp with a low output impedance. Transformer-coupled tube amps are one possible solution, but those tend to be expensive. Low OI OTL tube amps do exist as well though, like some of the more expensive Feliks Audio amps. I’ve actually ordered their Euforia last month specifically for my Empyrean, should ship some time next week hopefully.
So yeah, tubed planars can for sure be just as magical as tubed DD’s, you just need to be very specific about finding an amp that will have good electrical synergy with it, and then you’ll also need to ensure that the sonic characteristics of that amp complement your headphones in a desirable way. Or just buy your way out of the hassle and splurge on an AudioValve Solaris. All headphones I’ve heard on that amp somehow had their sound turned into liquid gold. From HD 660S’ to Susvara’s.