Dynaudio C4 speaker equipment matching

My first post, looking for advise.

My system includes:

Plinius CD101 CDP
Plinius Tautoro Pre Amp
Two Plinius SA-103's running in bridged mono configuration
Nordost Frey interconects(2m) and speaker cables(4m) Nordost Thor power conditioner and Brahma power cords (2m) attached to all equipment
Finite Element Signiture racks
Ceraballs and Cerabases
Dynaudio C4 speakers on spikes

The room is untreated and large, 12ft ceilings, 23ft long and 28ft wide. Speakers are 4ft from the wall rear wall. Listening is normally at moderate levels.

I listen to rock, male and female voices, acoustic guitar, a little RAP and techno. Broad taste.

I have a very large sound stage, which I love, though sound is to forward for my liking.

I am looking for more dynamic's, increased depth in the sound stage and greater bass control. I was thinking of starting with the CDP, was thinking of WADIA 861SE, Esoteric SA60/UX-01 or similar and was also thinking of going to Nordost Valhalla cables, though the pair I tried did not make a significant difference, to my suprise.

I was told that changing to a copper power cord on my preamp might help with depth of sound stage. Would appreciate any advise as to the weak links in my system and upgrade opportunities, biggest impact first. I want to keep the SA-103's amps.