Please Suggest Approaches to Perceived System Darkening

For the past couple months my system has begun to sound darker. I can't think of an auditory metaphor but in visual terms, it's as if what was once a clean window has accumulated a layer of grime. The highs seem more rolled off and overall, there's a lack of clarity that was not apparent before.  

Integrated (Wells Magestic), DAC (Aqua La Voce S2) and digital cable (Audio Art Statement) are tipped to the warm side. The digital cable is the most recent addition, purchased in the spring of this year.  

 Up until now, I've been very sensitive to bright sounding systems and have done all I could to avoid this. Now I find myself wanting more clarity.  I'm 65 so it could be hearing loss, I guess. I'd appreciate some suggestions re: how I might address this (besides getting my hearing checked). 


I had a Schiit Loki which I'd bought in an attempt to compensate for a somewhat unfocused of bottom end. However, acquiring Symposium shelves and rollerblocks rendered the Loki unneccessary, so I sold it.

It's unclear to me whether buying a Lokius and boosting highs would result in more clarity across all frequencies. 


I could try a different digital cable. This is an area where I have done little experimentation so I have no idea of 
how much of a difference this might make.


I could move from La Voce S2 to S3. I'm a bit leery of doing this after reading a 6Moons review in which the reviwer characterized the S3 as an outlier in the Aqua range, being, in his words, "lean and brash". These are characteristics I've always rejected in audio gear. I can't afford to move up to La Scala at this time. I prefer to stay with R2R ladder design.
I could spend 3K for a used DAC. 

An audiogon member suggested he could do a mod on the S2 to improve resolution but I'm reluctant to do this, not knowing how it might sound and being mindful of the fact that modded gear can be harder to sell. 

The "usual" approaches for lowering noise floor seem to include mechanical isolation, AC power treatment, and room treatments. 
Have your hearing checked. I went from a small loss of high frequencies to profoundly deaf (in one ear) in less than a year.