I use Roon EQ:
-3.8 db headroom correction
Sample rate conversion: Max PMC Rate (power of 2) = 705.6khz for 44.1 music
Sample rate conversion filter: precise, linear phase
Parametric EQ:
a +3b bass shelf at 100hz, Q: 0,71
a +2.5db Peak EQ at 2000hz, Q: 2
a -0.9db dip EQ at 2700, Q: 3.2
TBH, I always thought I did not like EQ. I used to EQ the Arya on the SP200 amp, but the Arya did not need fixing on the A90 as the harshness was gone and the Topping sounded more warm. Also, on the A90 I could clearly hear the soundstage and detail being reduced with EQ. I did not use Sample Rate conversion, as an result the sound was resampled back to 44.1 khz.
Now I do use Sample Rate conversion, which (even without EQ) I prefer over bit perfect on the D90! Never ever thought I would prefer upsampling, but with Roon I clearly do, it is extremely well implemented. This is vital for EQ quality> since the upsample signal is EQ-ed by Roon and does not need to be converted back to lower rates: now the EQ is 100% transparent and has absolutely no/zero audible negative impact on the signal.
Main reason I do like the EQ, it makes the Arya more dynamic, more intimate and improves PraT so rhythmic music clearly has more pace: without EQ the Arya have energy but a just a bit polite/analytical. This EQ gives the Arya balls and pace so to speak.
I can imagine younger ears prefer to add subtle -1 or -2db EQ around 5000 and 8000 hz, because these are well known Arya peaks. But for older ears like mine that extra energy in the treble is appreciated.
I simply cannot the fault the Arya with EQ> I do wish for more resolution (once you hear an Susvara you will know why) but other than that: this combination is genuinely spectaculair. I listen to electronic, techno, jazz, pop, modern classical, rap, film scores, r&b, singer/songwriter, etc. Every genre is mesmerizingly beautiful... pffff I need to get of the Arya and A90 is so amazing soap box.