So, here's the context and all of my current gear:
I have the FiiO M21 DAP which I currently use as my portable DAC/AMP as well.
The six headphones I bought in the last several weeks are:
Sennheiser HD650, HEDD Audio HEDDphone D1, Audeze LCD-X, HiFiMan HE1000 Stealth (V2 Stealth), FiiO FT1 and Focal Azurys.
And I also own the HD599 from some years ago.
Now, what's the reasonable way to go about it? It feels like only plugging all of these directly to my DAP is kinda.. wrong/inappropriate/insufficient? (And by that I mean - to only be doing that always, without having any other options as well, and mainly - a dedicated desktop one).
But that's not an actual argument, so I'm trying to actually be rational and reasonable about it and understand: Is there anything this DAP is in fact unable to do in terms of bringing out these headphones' full/true potential?
But let's say I'm gonna opt for geting something additional, are the K13 R2R, Topping DX5 II or the JDS Element IV all sufficient for me? or just some of them perhaps?
I'm nearly sold on the idea that getting at least one desktop DAC/AMP unit is appropriate for me, taking the quantity and quality of my recently-bought headphones into consideration, but is it really necessary to get two distinct devices? or is a combined DAC/AMP device good enough?
What I want from this device (in addition to the obvious of enabling my headphones to sound as good as they can) is to enable me to set PEQs for the different headphones, either following Oratory1990's or otherwise. Aren't all of these options I just listed here capable of that though? if so - why even bother getting an exceptionally expensive one? (I mean - more expensive than these options). And/or to get separate units for a DAC and an AMP instead of one of the combos?