What tube amp for Harbeth 40.1

@aj523 can you please elaborate more on what are the improvements?  My MC275 also can be switch to mono @150W.  So, I may buy another 275 down the road, but it is expensive.

alternatively, there is a MA6600 for sale locally with 200W per channel.  However, it is a SS, and i am not sure if I will like the sound.  But I will never know until I try it, I guess.  If it works, I can then sell my MC275.

I would like to share my update.

After I bought the McIntosh 275, it improves the bass compared to the 8W 300B. But the sound of the JBL 4344 keep swirling in my head, and I have been trying to see if I can make the Harbeth sounds like the 4344.
I wonder if adding a preamp will “improve” the sound further, I borrowed a Luxman a3300, but I don’t like the sound. I prefer the DAC goes directly into the amp. Then I borrow an Adcom GFA555 SS power amp with 200wpc. It sounds very different!!! It is more musical and more dynamic. It sounds “harder” and dryer. Musical instruments sound very good. I think for classical, I likely prefer SS.  However, for vocal, it is not as sweet, and the sound is less holographic. But I can understand why many prefer to use big power SS amp with Harbeth. I can see a potential, is it possible to find a SS amp that has the dynamics, but at the same time sound more tubey? I don’t think it is only because of bigger power, but also the SS vs Tube sound.

My budget is limited to $2000 since I spent a lot on the 275. I don’t want to sell it until I find something better. I have two thoughts:

1) get a better tube preamp such as Supratek with a cheaper SS amp. The Adcom GFA555 can be had for $500. Hopefully the tube preamp will give the tube sound.

2) get a better, vintage SS, such as a McIntosh, Luxman, Accuphase ... etc. I am looking at a McIntosh MC2155.
Which one will give me the best of both worlds?

You are discovering these chameleon qualities of the 40.1.  It always sounds good, but different amps, tube and SS, high and low powered, bring out further some of its elements.
This may sound harsh but the 40.1 really deserves more than can be bought with 2K.  Perhaps you could find an older McCormack or Belles.

@gte357s

Sorry just saw your post asking me to elaborate. I don’t have a musical ear and I’m not really expert in describing all the nuances but doubling up and adding a separate preamp with the full zotl architecture implemented clearly changed the sound top to bottom. Everything is more alive more dynamic like it woke up. I was most focused on the bass because thats the knock I got for going with the harbeths to begin with and the bass definitely has more slam more control. Hope that’s helpful. I know @ghasley passionately recommends Pass and Boulder integrated amps. That’s where I would pivot if I revert back to solid state in the future. 

"This may sound harsh but the 40.1 really deserves more than can be bought with 2K. Perhaps you could find an older McCormack or Belles."

Agree 100%....I mean if it were less revealing in nature like a C7, I could see going with a $2,000 amp, but not the 40's. I have been in your position many times, and this is where a good dealer could come in. Find better, and then sell your amp to get it. I'm thinking Luxman class A for my C7's, but I'm a ways off from making the move. Interesting that you mention the JBL's, since my main speakers are Altec Valencia's, with a Werner Jagusch crossover. Very nice setup gte.