Have a read on head fi, there’s a few people on there who have done write ups.

They’re supposed to be pretty fussy about amps, partly down to the low sensitivity, but also because of the unusually high impedance for a planar, which makes them very voltage hungry instead of current hungry like you see with most planars. Interestingly, based on what little I’ve read this means they can actually play surprisingly well with OTL amps (which are notoriously bad with planars due to their poor current delivery) thanks to their ability to easily push a lot of volts.

As mentioned before ZMF headstrap pads can fit. Alternatively, if you’re feeling creative you could do a comfort strap mod like this https://www.reddit.com/r/headphones/s/Dn1b2uiUWw

That’s referring to the volume control. Honestly I’m not sure what R2R actually means in real terms in that context, but it sure as hell isn’t the same thing as a resistor ladder DAC

Shouldn’t I be preferring the 800 S. I’m kinda confused by all of this.

It’s perfectly normal to prefer one sound signature over another, even if it’s a much more expensive headphone.

You’d be forgiven for thinking that compared to the HD600 series the HD800 would be a straight upgrade, the same but more and better. But it’s a different animal entirely, and the 600 series arguably still does certain things better than the 800.

Youve got two options, give it some time and learn to appreciate it for what it is, learn it’s strengths and weaknesses. Or if you’re able to, return it and save a whole heap of money. It’s your choice.

I don’t have the clear, but you’re probably best off going for a transformer coupled amp with switchable output impedance for the best/most versatile experience, that way you’d have more control over how much the frequency response is affected.

I recently picked up a second hand cayin HA-3A and I’m very impressed with it. The other potential options that spring to mind are the icon audio HP8 and woo audio WA6

APP2 aren’t bad, but I’d never expect them to compare to even entry level IEMs in terms of sound. You’re paying for convenience, form factor, and features.

The aria is by all accounts fine, although maybe a little dated now. The IEM market moves at a blistering pace, and there are now arguably better options at the same or lower price points.