Help needed to make system better, please

Sounds like a Cary SLP-98 would do what you want. I suggest the F1 mods. Maybe you could try one and see. 

Given the sensitivity of your speakers and the power of your amp it’s hard to fathom you lacking slam or dynamics.  I would first try an LTA MicroZOTL preamp (they offer a trial period) to see if that gives you some added detail and meat on the bones.  If you do this talk to them about the Ray Samuels tube upgrade as a possible option for your tastes.  Another one would be the Backert Rhumba or Rhumba Extreme (both of which are fully balanced).  For the slam and dynamics I have to think it’s a limitation of the speakers, so for that I’d add a couple subs because I don’t think an amp will really do it and the subs will also yield nice improvements in imaging and 3D soundstage as well.  Pass will likely be too laid back in the treble given that you’re looking for more detail up there and not less.  If I was starting from scratch knowing what you’re looking for I’d probably pair an LTA MicroZOTL or Backert Rhumba/Extreme pre with a Coda CS5.5 amp FWIW.  Hope this helps somewhat, and best of luck. 

A good tube preamp won’t be "slow or lacking in bass". You can get more "meat on the bone" with a tube preamp, but it’s not going to help you with slam or PRAT. Resolution and treble extension also shouldn’t suffer with a good example.

Like @soix mentioned above, it’s hard to believe that amp/speaker combo doesn’t have dynamics. You don’t mention your room size and your listening level.

I sit 10-11’ from speakers. Room is about 16’ x 22’ with left side open to kitchen and dining room. Speakers are about 9 1/2’ apart. 
I am wondering if Simaudio is too overly neutral. Is this possible?? My preference is listening around 65db. I want to stay balanced, if possible. I have Ayre P-5xe phono. Which I currently enjoy. Thinking about going tube phono. Possibly Manley Steelhead, or ??

but I feel Simaudio is detailed, quiet background of, soundstage and imaging is good. Just want thicker sound with equal detail and slightly more dynamic or PRAT. 

Unsure how much wiggle room you have with the primary listening position or if you’ve experimented in this regard, but have you tried sitting closer? If you’re 10 feet away, have you tried sitting closer to 7.8 - 8 feet away while also slightly adjusting toe-in? I’m thinking you probably have, so this will likely be ruled out, but if not may be worth a try.

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. 

@ghdprentice I was chasing a Simaudio integrated, did you just talk me out of it?
 

I don’t have formal room treatment. Carpet floors. Sofa and overstuffed chair. Plants in corners. Took many days of speaker movement , measuring and toe in, toe out to get where it sounds good but lifeless. I don’t want to bash. But I believe now that components can be overly neutral and dead sounding. Benchmark to my ears is worse than Simaudio. Very detailed and quiet but no emotion. No PRAT. 

Pass X250.8 and BAT VK-33SE is excellent combination...

JL35 I do believe that combination would sound great, and be good with most any speakers. 

JL35 I do believe that combination would sound great, and be good with most any speakers. 

Be nice to see a room measurement to know whether you need more diffusion. Your equipment sounds very nice.

I find if you want to get a feel for the field of possibilities find a dealer and listen a Luxman integrated (or SIM), Pass Integrated (several power levels available), and an Audio research I-50. You get the detailed / shiny (High Fi sounding) almost no Prat or midrange bloom, intermediate (Pass), and rich and musical (ARC). You will fall in love with one of them. Most brands fall on this spectrum. You want to make absolutely sure you match your tastes with the flavor you buy.

I have Daedalus Apollos and run them with Pass 30.8 via VAC preamp, and I do not feel a lack of slam and dynamics.  As others have mentioned, a sub may yield what you are looking to add for added dynamics and slam.  
 

if you are looking to swap out to a tubed phono, VAC makes great preamps with integrated phono.  This may yield a sound with more “meat on the bones” than you currently are experiencing.  

65 dB isn't very loud. My system sounds bleached and anemic at 65 dB.

At 85 it sounds magnificent, glorious, powerful, wonderful!

I have looked into VAC. Beautiful. Great sound. I really want to continue running full balance. I think I know the answer to my question. BAT VK-53se or BAT VK-90 with Pass Labs X250.8 or better yet, CODA #16 amp. Just lurking and fishing for people who tried the combination. Also, I enjoy learning of other brands, and best of all, other people’s approaches to achieve what I am asking. 3+3=6. But 2+4 also equals 6. Different approaches. Always looking to learn 

Your speakers are fairly efficient, so maybe only the CODA 5.5 instead of the 16 and then use the savings on a great sub too?  
 

I am sure the BAT would be a nice choice for a linestage.  The VAC I use (Signature Mk IIa SE) is fully balanced as I wished to run the Pass 30.8 fully balanced as well. 
 

let us know what you decide and the results! 

I already own two great subs. Rythmik FV-15HP. I have them set around 28hz, and turned down to accent. I am a bass head, but don’t want loud thumping. I like the bass to augment. I have felt, for awhile, selling the Simaudio and picking up a BAT preamp, or ARC. But I am worried ARC has upper midrange glare. Never heard the newer ARC reference preamps. My hearing prefers a slight darker but detailed sound. Bass definition, extension, and slam. I heard Pass Labs. Like the midrange thickness, but Simaudio is quieter and possibly more detailed. Never actually heard side by side to directly compare. Really enjoyed listening to CODA amp. Extended on both ends. Effortless sound. Beautiful. But, have not heard with BAT preamp. 
Again, just looking for some ideas. A little new knowledge. And different ideas! I appreciate all answers. I love the many ways to obtain good sound. 

@grislybutter ...*L*  I dunno....given the entry fee for a Sim Aud....?

Gotta reeealy want it..... ;)

Subwoofers will add a sense of fullness to the musical texture.

@asvjerry I am looking at used. What would you recommend that's comparable, solid state integrated?

I have the same sub as the OP. Consider moving your sub crossover to 50 Hz and high passing your mains at the same frequency. You will have slam galore. 

@OP, I previously owned a Sim Moon P5/W5. I kept preamp for over ten years, but changed the power amp more quickly as it had more of the slightly dry sterile sound you mention.

As regards Pass, you need to give them a bit of time to adjust to their presentation when coming from a more "transistory" sound. The amps have accurate pace and rhythm and present detail accurately when compared to live music.

You get what you pay for in terms of quality - the more expensive models are better. It is worth listening to the XP-27 preamp in particular and it would be interesting for you to try one with your existing power amp as a starting point.

It you want a half way house between Sim Moon and Pass - have a listen to Gryphon.

G2the2nd that is a good idea. One that I have not tried. I may have found my weekend plans. Thank you. 

@grislybutter.... Friend Gb, I'm likely to be the worst case scenario to comment on integrated amps, since I've never owned one....

Began with a few receivers, the last being a Marantz...followed by a Kenwood 'L' separate system with the mono amps at speaker-side...

Since, I've been using a distribution amp that allows to bi-, tri-, or even quad lines from an active Xover.....not to mention all that's 'upstream' from that amp.

If I did anything, I'd move onto a better version of it, or duplicate it; I'm a believer in the 'first watt' concept, and dist amps are generally <100 rms which I'm good with.

To drive subs, I apply an 'in-hand' receiver with tape in/out to use it's higher power level potential.

Yeah, not so SOTA, but I'm generally happy with the results.
As a 'kinda-phile' that wears aids ( really nice ones', tho' ), having to be able to hear the 1st violinist sweat isn't my goal at the end of the day...🤷‍♂️😉

Rather than BS anyone, I guess I'll just have to party-poop the query.

Mia culpa....

@asvjerry it's all, I am always learning. It's my constraint to be looking for an integrated to hopefully stop tweaking. Until I won't 

Gb, back 'atcha'....👍😎
"Learn something new every day, even if it's only not to do That again..."

Worse case scenario, determined long ago prior to spouse:
Wake up next to a woman and not remember her name....
"Hi....Uh, did we have a good time?"
(Stall and pray to one's demon you'll drag the Right One from the depths of the what's left of the gray matter...)

Thankfully, I did....and, Yes it was, having been on repeat....;) *G*

I have noticed a gaggle of new D specimens being offered of late.  There's that discussion whereas a few of 'us' ancients are considering dialing down their stacks of stuff....moving into a small home, waf has thinned along with her tolerance, or the move into a "...progressive Life Plan Community..."   where the Mac Stack would take up most of the room....(and you'd be better off with some really nice BT'd 'phones with a good cell....)...

But I'm down w'you on used...of the 30ish items I've bailed together, only 8.5 were new, once upon..... ' .5 ' due to 4 identical ESS large AMTs'; 2 new, 2 used...
...and one is a DIY switchbox for TT's, with or without phonopre's.....

All of the clutter I abuse to DIY my omni-scat toys is and has to be new...

Al, Ti sheets....foams....hardwares...knowledge, being the hardest....

Oh, and new drivers to slash up for their frames, magnets, and voice coils....
At least, the latter I can shop 'bout for desirable details....  Keeping in mind and hand the bang/buck ratio, 4 min 5 best.

Want to play with 'voicing', so to speaker (ow!*L*)

Listen to what 'flat' doesn't sound like...🤦‍♂️🤷‍♂️🙄😆

Obscure play. 

Well, after all of that I can only add the proverbial time tested endlessly debated triggering….. wait for it…. ACTIVE.  Yes, ATC active.  You can imitate an iRobot vacuum running into furniture and cats changing direction or finally give it a shot.

Best luck on your quest.

@sputz I’m using a BAT VK-80 preamp on my system and couldn’t be happier. I came from a Holo Audio Serene KTE preamp that was very transparent, and it was good in its own right. Going to this tube preamp was a big jump for me. Using it with my Coda #8 amp.