Alright so I'm back from Richer Sounds.
Firstly the amp they let me demo the HD800S on was the recent
Cambridge Audio EXA, it has a single ended 6.35mm output so I just used that. It's headphones output power specs are not mentioned anywhere it seems so I don't actually know how good it is, nevertheless it's a £2000 integrated so I imagine it to be somewhat decent although probably not as high quality as dedicated DAC and headphone amps like what we have talked about in this thread.
It was connected to a node via XLR and Tidal Connect and Quboz were available.
First up the HD800S, they feel good quality, similar in weight in the hands and on the head to the Arya Stealth, but there are more areas on the HD800S that can get damaged if you poke a finger without care, those chrome grilles on the outside of the cups can be pressed in for example. The earpads also feel a bit pants, not memory foam, just normal foam and the padding is very thin as well, although they were comfortable regardless when on my head.
I played familiar songs and immediately obvious was the lack of low bass extension which exists in those songs as I hear them on my speakers and the Arya. I checked no EQ or tone controls were enabled on the EXA, all good, but still the low end felt missing, probably because I'm so accustomed to planar bass now. The soundstage was there but had that classic Sennheiser veil that I remember from my HD650 and HD660S2. the upper range detail didn't have the crystal clear sparkle that is present with the Arya, maybe this is an amp trait in the demo room though as teh EXA100 uses ESS chips and is tuned to be warm/smooth.
I asked the staff to check if they had any planars in to demo to confirm this, he pulled out a pair of Sundara 2020, perfect as i know the signature well having owned them. The bass extension was back on the same tracks! The upper end sparkle was there too but just with the brightness peak the Sundara is known for. I also forgot how uncomfortable the earpad shape of the Sundara was
HEDEGAARD - Ratchets is a prime example of a song that has a bit of everything, from super low bass extension to upper range sparkle, a well rounded headphone in both extremes will carry that track beautifully and to my ears the Arya Stealth with the memory foam velour pads does that nicely. With these songs I was not really hearing £1100 worth of sound, the Sundara was more fun by comparison.
So yeah I don't think any dynamic driver headphone will ever impress me now :/ Institutionalised by planars!