Effective recommendations to add warmth & smoothness while keeping bass control

Tube preamp and amp, 

if you mean warm with max slam the tube preamp + Pass XA amp (there are fare others)..

Thank you, @yyzsantabarbara.  Couple of questions.

1. Will the CODA 11 run hot?  I’ve heard that with CODA’s heatsink fluid technology, many of their Class-A amplifiers run only moderately hot — around 100–105°F. Is this true for the CODA 11?

2. I noticed its damping factor is still as high as 100 despite having no global feedback.  Based on that, I assume it should still offer good bass control. Is that correct?

3. What is a reasonable asking price for a CODA 11? I’ve seen used prices range anywhere from $1,800 to $3,500.

Warmth and bass control are tightly coupled in most cases. Amplifiers that don’t properly drive speakers (woofers is where the challenge is) will sound brittle and thin. Match your speakers with high current class A or A/B amplifiers based on impedance, required power and the desired sound signature. 
Coda is a great choice but again depends on speakers. Keep in mind Coda amps are not warm sounding. They’re very clear and transparent. I’d say they are slightly on a cooler side sonically but with great bass control given proper speaker matching. Coda no.8 is offered in 3 versions and you can have Coda change your amp to whatever version you prefer out of available 3 choices. 
The no.8 does not run very hot. Much cooler than Pass. 
 

Thank you, @ghdprentice. 

I tend to agree that a tube preamp + solid-state amp will be the most effective approach. But since the Pass XA series runs in pure Class A, would that combination end up sounding too warm?

I don’t want to trouble you with specific preamp recommendations, but I’d like your general impression of Audio Research versus Conrad-Johnson. In general, are AR tube preamps more neutral than CJ? If so, would using an AR tube preamp with my current solid-state amp still be effective in adding warmth to the system?

@lanx0003 what speakers are you using? 
ARC tube preamps, especially models made in the last 8-10 years, are focused on adding as less of any type of coloration as possible. Some say they sound like solid state. I disagree. There’s smoothness associated with tubes but other than that they’re pretty much neutral. No bloating in the bass. Very accurate.
Great pairing with Pass amps because they don’t compound the effect of an already warm Pass sound signature.
If you want more of a classic tube sound with ARC then the older Ref1 or Ref3 would be a good fit. Huge bass, warm sound. 
As to CJ, they’re sweeter and not as neutral. I would pair CJ with Coda amps.