My Yggrasil is still v1. It's well broken in and stays powered on at all times. I don't suspect Yggy of being a contributor to my issue. This shouty quality has gotten in the way of my enjoying my setup for years, through multitudes of upgrades and changes. I've been able to reduce it but not eliminate it, and as the system has become more capable in terms of resolution the remaining harshness just seems to become that much more obvious.
To some extent it's become sort of a "I don't know where to start anymore" kind of problem. I've gone through amps, dacs, cables, and through it all I've never been totally happy with what I hear.
Not knowing your degree of technical experience etc. and going by what you stated above, it sounds like there is an aspect that is common to ALL of the experimentation you have performed thus far.
And one, all to easily overlooked aspect, is the power being delivered and used by the entire system.
There are a few easy (relatively speaking if you know what you're doing) electrical checks and experiments to try.
#1 measure the voltage both AC and DC between neutral and ground at the duplex receptacle that is feeding your system.
There should be a very low amount of AC (less than 1/2 volt, preferably much less) and no DC voltage.
These voltages should also be steady and not jump around.
#2 Have you ever replaced the duplex receptacle(s) in the wall?
In some cases, especially in older buildings, they can 'wear out' and become a source of noise and limit the current flow, with subsequent deterioration of the SQ of the entire system.
One way to tell if they should be changed is, is the plug held securely and not be able to wiggle or vibrate in the receptacle?
#3 In some situations the AC power can be 'contaminated' with the noise generated by other loads in the same breaker panel, and if your audio system shares the same phase in the panel, this contamination will propagate into the audio system.
Moving the branch circuit that feeds your system, to the other phase in the breaker panel, can sometimes alleviate this spurious noise.
#4 is the ground connection back at the panel in good shape?
Or is the ground 'floating' that your audio system is using?
A ground that is contaminated with electrical noise will add unwanted masking and other deleterious effects, such as harshness and can raise the noise floor.
#5 as an experiment you might try an 'audio grade' duplex receptacle instead of the usual ¢99 hardware store contractor grade receptacle that is ubiquitous, because it is the cheapest the contractor could find when the electrical system was installed.
I would recommend a Cryo'd receptacle which can be found for as low as ≈ $25.
All of the above is fairly light duty in terms of what can be done easily.
There is another level (or 2) you can take this too, and it is a good practice for the health and safety of your electrical service.
BUT it means you MUST KNOW WHAT YOU ARE DOING!
What is entailed is to trip every branch circuit breaker in your panel, off, then wait 1-2 seconds then back on.
Feel the action of the breaker as it trips in both directions and make sure they all feel and work the same.
If any breaker feels different or doesn't work properly, replace it and avoid bigger problems down the road.
And if you do feel like you want to go this extra step, or get someone who can,
When the breaker is tripped off, make sure the clamp/set screw is tight,
and or, pull the wire out and make sure it isn't corroded/discolored/damaged in any way.
Especially check any wire that was loose in the breaker where the clamp/set screw was loose when you first checked it.
All of the above assumes you know how to use a DVM and are familiar with how to handle live AC power circuits.
If not, then an electrician or a technically oriented friend who does have this experience should be brought in to help.
IOW
BE CAREFUL,
you can all to easily kill yourself, weld your screwdriver across the 220amp (or more) service feeds, or other mishap.
This is not for the non technically oriented DIY'r, but it isn't rocket surgery either, at least for those with the requisite proclivities.
And yeah there is much more to all of this, but the suitability of the power being fed to our systems can sometimes be problematic, in and of itself.
JJ