Whats the FATTEST sounding Tube amp to warm up Lean speakers?

Former Merlin VSM owner.  The Merlin's do a lot of things right and they can be very seductive but their lean bass drove me nuts.  I went down a similar path that your are now traveling and I can tell you how it will end.....with a Merlin for sale ad here on Audiogon. 

Just fired up the Joule electra 100 amps. Wow- what a sound!
Im starting to be happy. I think the Merlins are an acquired taste... But the 15" Sub i bought definitely helps for real earth shaking when needed. I just need to add the EQ for some sweetening and im a happy camper.

@drumbeatCongrats on the Joules!! Curious what type and brand of output tubes does it comes with? I ask because I've seen replies stating 6550 - KT88 etc (myself included). When I mentioned TS 6550 solid plate vintage I did because they are very warm sounding. SED 6550 on the other hand are very linear where the SED KT88 is very warm. Vintage GEC KT88's are also a very linear and clear sound. Current production Gold Lion KT88 are in the middle leaning slightly leaning toward a linear sound. What I'm trying to say is you can't state a type of tube (6550/KT88) has a specific sound characteristic.

@xti16 All Joule-Electra power amplifiers (excluding the very few hybrid integrated amps Joule made which were solid state ouput) used the Russian 6C33 output tube. Most all were made in the Soviet era IIRC.

Rich