Congrats, this is insane value in the scheme of current audio affairs, and functionality and technically wise, leaps and bounds ahead of 99,8% of hifi DACs.
USB and one settingbfor both channels is better than nothing, but PEQ, to be really usefull has to be available separately to each channel, to all inputs, as most of us want to use at least two sources and be able to extract the best sound quality for all...and, have different PEQ memory settings for each input, desirably a couple for each, like, just for TV I may have a setting for speech, (news and series) and different ones for movies or concerts..
However, everybody is shouting rightly so, "We want PEQ", but EQ is not in my opinion the only thing you need on a DAC ( I will leave DRC out here..),
You absolutely need variable, adjustable loudness baked in, if you don't listen at the same volume every time....
The one thing no one else other than RME to my knowledge has come up with, is a completely variable, user programable and tunable Loudness feature like the
ADI Dacs. It lets you program how much of it, and the tapering down of the effect and at volume the compensantion finishes, wich is essencial for it to work correctly and give you its benefits.
This is in my opinion almost if not ss usefull as EQ, as I find the magnitude of the effect this has on sound perception is easily as notable as a PEQ corrected speaker in an actual listening space, if you vary somewhat your listening level like I do (super low working, low, eating or background, lowish in the evening ,normal during the day, all hell breaks loose here and there for a bit..).
Plus, not just some, but All speakers and rooms benefit, wether lousy or those already with actual textbook in-room response, because this effect is always present and only has to do withthe actual listening volume spl (see Fletcher-Munsoon curves).
However, no one seems to ask for this features... I think that unwillingness it has to do with the old, too heavy handed on and off and fixed implementations, and the straight path, no editing audiophile snobbery..If lthey heard it properly done like the old Yamaha (limited flexibility, but better than nothing) and especially the fully programable and variable kind like RME does in their DACs, they would never want to go without. ...Instead, everyone EQs their system to a set volume, the one they listen the most, effectevelly baking in some loudness corretion, so their system only sounds correct at that spl, and listen in dissatisfaction when their program changes, they change the volume , or switch to a source with different gain or overall playback level.
This feature single-handledly secured an immovable status of the RME as the center piece of my system,as for now I can't get that anywhere, not in DACs, Roon, Streamers EQ or DRC software that I know of.
Topping has done a stellar job ,pushing the envelope and at a very good price (the reliability and political considerations I will leave up to you)
I hope manufacturers in general go down this path too with the PEQ, but someone else than RME must implement the programable loudness feature.j
Just as EQ, it needs to be baked in if you want correct reprodution, any time , at all listening levels.