"warm" solid state integrated amplifier

The Boulder 866 leans to the warmer side. Also very neutral. 

I want to second the recommendation for the Krell K 300i. I have been using this amp to push my Maggie 1.7i speakers for over a year now. The power is produced via a patent pending new circuit design called Sliding Bias - this keeps the amp in Class A power longer and running cooler than other Class A designs. It’s midrange on vocals is unsurpassed in it’s price range.

Happy Listening!

The usual gear or tweaks/room dilemma seems to have arisen again on this thread. I don't see why they're opposed. The OP is looking for a warmer sound.

We don't know the extent to which the OP has dealt with isolation and other tweaks, nor do we know the kind of room being dealt with or that room's treatments.

If I was the one posting, I would be ready to invest in a new amp only after those other factors had proved ineffectual. Because then I would know the true sound of any amp being tried. I see no reason that this is a dilemma. It's a sequence and we don't know where the OP is in that sequence, yet.

The Krell K-300i mentioned above a few times is great. Get it with the DAC card and you have a fantastic all-in-one, including HDMI eARC. I've had that and the Ayre AX-5 Twenty at the same time in my system and could live with either. The Ayre was warmer but not as detailed as the Krell. I would take the Ayre personally but you only get analogue, no digital available.

@millercarbon is on point and I have dealt with similar issues in a simalar fashion. Als look at the Simaudio line. SS on the warmer side. 380 or 600. 
 

Another choice could be a hybrid like Pthos or Vincent.