Advice on Equipment Upgrade

FWIW I run an ARC sp-16 pre-amp with Bel Canto ref1000m monoblocks (1000kohm input impedance, unbalanced).

I was listening to this running my small Dynaudio Contour 1.3mkII monitors for hours last night (did not get much sleep). The sound is a magical combo of low fatigue, high detail, and excellent dynamics in the 12X12 office where they are located. I would strongly consider giving a good Class D Icepower amp designed to mate well with a tube pre-amp like any of the current BCs, or Wyred4Sound (65kohm input impedance ~ as I recall), an audition with any Dynaudio speakers.

These beefed up Icepower amps used with tube pre-amp are hard to beat IMHO. My system is very responsive to changes in ICs as well as a means of tweaking the sound. I like DNM Reson ICs for best overall performance including marvelous vocal detail that enables every word sung to be heard, but I also use less expensive MIT terminator ICs as an option for a less forward sound with more emphasis on the bass. Others would deliver other sonic variations effectively as well I am certain.

Stock Icepower amps are only 10Kohm, not a great match. BC, Wyred and perhaps others that target the high end home audio market add proprietary input stages to enable better performance with most tube pre-amps.

Rogue and Conrad Johnson preamps have low output impedance that might match well with your 20kOhm amp input. (Rogue has 450 Ohm output). You should also check on the specs of a BAT preamp.

I think I'm finally getting it -- I'm a drummer so it takes me a while. Sounds like you're getting the fullness and tone from elements like drum shells, but you're missing some of the transient snap and attack of the stick hitting the drum heads and perhaps a bit of crack from the snare, no? If that's the case I think before looking into swapping out equipment and because you seem happy with other aspects of the sound you're getting I might try a new interconnect (I'd think your speaker cables are probably fine). I'm not familiar with the Morrow ICs so this might be off base, but maybe trying a Nordost IC or a silver IC from another brand (others might have recommendations for that) might provide enough of that detail, snap, and drive you're seeking without resorting to flipping components. Just something else to think about, and best of luck.

Different ICs might help or make a difference.

I'd recommend DNM Reson ICs for this application. THey are extremely clean and coherent with fantastic transient dynamics in my rig. If they do not help in the areas of concern, then probably no IC alone will.

Why start experimenting with ICs when the pre and amp impedance are obviously not a match? Tls49 and others have directed you to the most likely problem.