Integrated Amp Advice - Rogue Sphinx or Peachtree nova150?

I have the Peachtree Nova 220 SE and only paid $800 for it .

" How is the DAC and phono stage in the nova? "

I'd say respectable / good sounding. Quiet without any background noise, Preamp has exceptional S/N ratio.
Overall a solid unit. 
It will drive the 4 ohm load / low sensitivity very nicely.  

I owned a Peachtree Nova, I think it was @ 80wpc. Very solid amp punching well outside its weight. It’s been a few years but I recall it was slightly “rough around the edges” to my ears. My main amp was a Primaluna tube integrated though.

Recently purchased a pair pair of Harbeth C7ES3 which I would not classify as terribly efficient and drank the Harbeth kool-aid of higher power, higher power and sold my tubes and went with the Rogue Sphinx. It was a really good decision, in my case. The tube amp was running out of gas at higher listening levels.

I immediately replaced the JJ 12AU7’s with a Gold Lions which I loved in my tube integrated.  If you can listen to both you’ll be miles ahead in your decision making process.  

Hope this helped.  

How is the DAC and phono stage in the nova?

Great price on the Peachtree. I personally would snag it for under a grand. Plus you can upgrade to a different amp down the road using the Nova 150 as the front end preamp / DAC combo. Excellent with room to upgrade worked for me.

get a used grand integrated (around 1500) swap the 2 crappy chinese 12au7s for proper nos 1950-1975 (100-300$ ) and you are sorted. looks like the best amp they ever made. it was 4000$ in 2013 and they are not making anything in that range anymore
 

Musical Fidelity M6i .  Power with musical finesse.

Matt, sounds like a good plan you have. I used to own a Peachtree Nova 125se....it's a remarkable value....does everything pretty well, just not great but given the price point a formidable product.

If you could stretch for it, that Kinki Studio EX-M1 for $1770 at TMR might be a good fit...

I always hear that Thiel speakers aren't easy to drive. I don't think either of those is the optimum choice. 

I think the Nova is at a great price! I understand you might prefer a tube sound. One option could be to buy the Peachtree and use the Jolida Tube buffer with the loop inputs of the PT to get the tube sound.  https://www.jolida.com/product/foz-ss-x
Might be the best of both worlds. Maybe the dealer would let you try it before buying. The preamp and DAC of the Peachtree seem to be held in high regard, as well as its ability to drive 4 ohm loads. The FOZ is $400. If this combo doesn’t give you what you’re looking forward - should be fairly simple to resell.

Listen to something ... anything ... before deciding!