Help needed to make system better, please

What specifically do you mean by “thicker sound?”  Do you mean something like greater tonal density in the mids or fuller bass, etc.?

I am afraid you are describing Sim Moon products. That is how they sound. I am familiar with them and have owned and auditioned others. The 700 series are the driest and most transparent and lifeless.

I have owned Sim Audio in the past. It tends to be detailed with a lack of midrange bloom and PRaT. I had a SIM 650D DAC / CD Player with the outboard power supply ($18K together) . The 700 series is even more detailed scraping and dry sounding.

While I had a good Audio Research Ref tube preamp, the source was detailed and transparent but lean an analytical sounding with the SIM. No amount of follow on warmth could make up for its shortcomings.

Good Prat will come from good quality tubed equipment although Pass Xa series equipment is very good for solid state, and newer X is getting much better. You want to get a good tubed preamp, and warm yet detailed DAC / streamer. Then look into a better amp... maybe Pass XA, or maybe Krell.

The system I have now is exactly what you describe except for the slam. My system has outstanding bass, but it is not brick wall fast and gone bass. It is thick rich and emotionally involving. You can see my systems under my userID. 

@sputz 

Whenever I hear about lack of microdynamics, PRAT and speed using higher efficiency speakers I always find out what preamp the person has because preamp gain and potential are the next biggest factors. 

In your case the Simaudio Moon preamp has 9db of gain.  This is adequate but low imho.  Having had a gamut of preamps that much gain is definitely causing your system's lack of energy. 

Seek a new preamp with at least 15dd and preferably 20db. 

The previously mentioned Cary Audio SL-98P will definitely work, if you want even better the Cary Audio SLP-05 has incredible dynamics, separation, PraT and all out energy.  I have run one for 4 years and wouldn't change a thing.  

Thank you ghdprentce. That is exactly my impression. I was trying to say without say. I didn’t want to bash any brand. I was fishing for information or opinions on BAT preamp or Pass Labs X250.8 vs Simaudio 760a. 
my ideal would be BAT VK-90 or VK-53se with CODA NO. 16 amp. That is my dream with the DAEDALUS or LAWRENCE double bass, or even Cello. 

Whether room treatments is use is not mentioned.
If none are in use… they do work.