Help choose best amp/preamp combo?

Hi there
I am new to audio forum.Helo every one here can help me.I do build a 2 channel stereo with JBL is my system :Parasound a21 amp + Emotiva xsp1(gen 2)+ pair of B&W 805 Nautilus.To be honest, I do loved the sound system very clear and crisp on high and midrange with powerful bass tights.but it is LACKing of Warm sound.I do loved the warm sound is top priority.couple months ago I do have Rotel 1095 amp pair with Rotel rsp1570 + b&w cdm1 Nt sound is clear crisp and WARMER but sound is THIN compare to Parasound.but Rotel sound is warm which I like much.I also heard that Parasound a21 is warm sound too.but in my taste it is question is the amp do produce a warm sound or Pre-amp produce a warm sound or the speaker do make the sound warm?I am confused and I want change my system to Rotel rb1582mk2 + Rotel rc1580 pre-amp because I heard that B&W speaker and Rotel is relate to each other and their product is matching together in sound.especially BW speakers is sound good with Rotel this true.and how you guy advised me to keep Parasound a21 and changing Pre-amp to either Parasound P5 or Rotel rc1580? Or go full system with Rotel like Rotel rb1582mk2 + Rotel rc1580?I am confused now and need your help.Thank You in advance.
The A21 is a very nice amp with solid reputation. I’d look into a tube preamp that has the tonality you want. If you are willing to go used, a quick search shows these choices all under 1k. Be sure to check output impedance to ensure compatibility with the A21.
A21 is a very nice amp; not sure I'd ditch it for a Rotel. A tube preamp as mentioned above will probably do the trick and there's plenty to choose from so hopefully you have a local dealer that will let you drag one home first. Cables will make a big difference, especially a nice power cord on your amp. Lastly play with room treatments as your room might just be hot to begin with.

have you considered buying different speakers?

not a B&W fan myself so I have a bias...

good luck
Thank You for all your help.I will try Rotel rb1582Mk2 and see how the sound going.I do loved my B&W 805 so much and I won't change it.If I do change it I will upgrade it to 805 D2 or rb1582mk2 will arrive next week and will let you guy know how it is work.Audiogon forum is very helpful and wonderful place to learn audio gear.Thanks again to all you guy for helping me.
I may try looking for Mcintosh tube Pre-amp like c2200 see how it's work. If I try tube Pre-amp it must be Mac.I won't try the other brand tube Pre-amp because they look so ugly.I do like both warm sound and beautiful appearing like Mcintosh tube Pre-amp.It is just my though or my dream because Mac stuff is so expensive.