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

What would you say is the fattest, warmest fullest sounding Tube amp to fatten up
Merlin VSM's?

They are 8 ohm, and easy to drive. 30wpc would do.

From my understanding, through reading here, the Famous match with AtmaSphere s30 actually doubles up on the natural detailed and spacious yet lean character of the Merlins.

Which Amp would do the opposite - be a little forgiving and sweet in the higher mids and fatter and fuller in the lower mids?

Thanks