"Warm Sounding" Solid State Amplifiers

Before considerations of "warm", what about things you are sensitive to in a negative sense?  SS amps with low measured THD but relatively high levels of odd order harmonics?  Hate them.

Tube amps with sloggy, lazy, rotten tomato being hit by a mallet bass?  Hate them.

Also any amp that has colorations in one band but not another?  Hate them too.

So outside of frightfully expensive tubes - they are out for me (in amps, not pre-amps or DACs).  Retubing amps with any sort of top shelf  tube gets very expensive as well.

So, first wipe that type of thing off of your list (things you don't liek).  Are you keeping your speakers a long time?   Good.  What do others say works well with them - good way to start a listening list.

Warm?  Class A, Class A->AB, fets - I think most of your warm amps that are not tubes will be found to have one or more of these traits.  My amp is a Pass X-150, got the A->AB and the right sort of transistors.  Clean, fast, of one piece from top to bottom, depth, accurate with a bit of sweetness, lots of current, will drive ML's, Maggies, even Duettas.  I found mine, hopefully you'll find yours.

A bit of a long overdue update on this discussion. 

I definitely didn't realize the can of worms that I was about to open before I began the discussion but it has been highly enlightening.

Earlier in the thread I accused Bryston amps of sounding too neutral and sterile and I wanted something different. Among the Bryston amps I own and have owned are the 7B ST's, 7B THX's, 7B SST2's, 4B THX and some old 4B pros.

I bought a Threshold T-400 in the summer of 2015. When it first arrived at my door I had to send it out for repairs immediately. The repairs were done by an independent tech and the repairs were seemingly successful. The sound was sweet and smooth but the only thing about it that was "warm" was the unit itself. Because of it's 300 watt idling current the damn thing is like a small furnace. Not very ideal in the summer time and also a drag on the electric bills. Listening sessions would be cut short due to the excessive temperature build up in my 2nd floor listening room.

I finally had enough and I pulled the trigger last week on a Bryston 4B THX. Having previously owned a pair of 7B THX's I was very certain of what I was getting myself into. The day after I had committed myself to the 4B THX my friend Murphy paid me a random visit. He's a lawyer and whenever he shows up, things seem to go sideways. In this case the right channel of my Threshold started to distort significantly. After a quick round of trouble shooting it was obvious that it needed to go back to the shop - Again. And this time, to a different shop.

The Threshold is still in the shop but I will wait to "Pass" my final judgement until it has a clean bill of health from my new tech. The T-400 is a highly esteemed amp with somewhat of a cult status to it. Many describe it as one of Nelson's best sounding amps. I found it to be sweet and smooth but even with silver speaker wire (Audioquest Comet) the midrange seemed a little too laid back and the bass always seemed shy or muted through my Monitor Audio Gold GX 300's. Until I plugged in the 4B THX I wasn't really sure if those issues were because of the speakers or the amp.

The 4B THX brought my system to life again. The bass had the weight, depth and control that you can expect from a Bryston amp. The midrange had a forward sounding presence. The soundstage was big and wide and overall very dynamic. I had to change the speaker wire to my Audioquest CV-8 (all copper) to get the right balance but overall I found the Bryston to offer a more musical experience.

I will be fair and re-audition the Threshold once again after it comes back from the shop but it is very likely that the Bryston will stay in my system!

I would have a serious look at channel Island amplifiers, I have there small mono block amps which sadly are no longer available  paired with a good tube pre there amps are amazing.The mid range is incredible and I will not be letting them go.Check them out used or new you will have to spend thousands more to get better sound.No I do not work for them it's all in the ears

Audio Refinement electronics. No longer manufacturered, but can be had on the second hand market if you are patient.