Vandersteen's new affordable mono blocks at the CES 18

Well.... only a comparison between the Ayre VX-R Twenty and the Vandersteen M7-HPA possible in my system and that is somewhat problematic because of the external filter required for the Ayre and a cable change I made to AQ wild Blue Yonder ( necessitated by mono blocks )...

the other amps are single ended and in the case of the Bryston underpowered for the task and I am not going to buy a SE Model 7 high pass filter to do a test for them nor the 400a.  Any excellent Vandersteen amp dealer will have the needed gear and a wide variety of amplifiers to try :-)

i am not much of a review writer, but I will put some summary thoughts together...stay tuned...

A partial listing of the equipment in my system includes: Vandersteen 5A Carbons, Pass XP-22, PS Audio Directstream DAC, PS Audio P20 power regenerator, VPI Classic 4, a Roon server and currently one gaping hole because I have no amps since I sold my Pass XA60.8s. I’m going to be getting a loaner amp in a day or two to tide me over.

Compared to the XA60.8s, I felt that the M5-HPAs sounded smoother and instruments sounded more natural. I had mentioned somewhere else the saxophone on the "The girl from Ipanema". When it hit, it just sort of jumped out at me as sounding like it was weightier and almost right in the room with me. Massed strings are less emphasized and more as part of a cohesive top to bottom presentation. I was pretty happy with XA60.8s when I had my Quatro CTs, but the more open midrange on the 5ACs made me feel something was amiss that no room treatment, positioning or Roon DSP tweaking could ameliorate. Essentially, there was a glare in the upper midrange - at times. On good days, when I wasn’t too fatigued from other things and perhaps the AC quality was good, (P20 is only on upstream components), I could be floored with my setup. At other times, trying to get through an extremely difficult piece to do well on a system - for example, Brahms 3rd symphony, especially the opening, was a bit fatiguing. RV himself chalks this up to the XA60.8s having global negative feedback, which causes time smear and is especially evident with his time and phase correct speakers. Also, I’m sure something could be said for the simpler circuit path in his M5-HPAs. All I can say is that once I heard the M5-HPA’s, there was no going back. Now, my Pass XP-22 sounded great to me and I plan to keep it in the system. It is exceedingly neutral and very low in distortion. Is feedback an issue with it? I can’t say, but I’d be curious to know what others think. I suppose some would say for a system like mine especially, that you should banish all traces of it.

@earthtones,
Thanks for the response.
Feedback, or more importantly, the lack of, seems to be a feature that makes Vandy's sing.
Bob

I'm sure you will fall in love with these new amps.  

I notice you are using Roon.  I love what Roon does, but it's not the best sounding program for digital.  JRiver is a much better sounding program to use for digital.  Matt Clott, who now write for TAS is a very close friend who is a digital guy.  He's been going back and forth with Roon vs others and what control programs sound best and why.  I am now using only JRiver through my The Memory Player by Laufer Technik.  

You may also want to try JRiver vs Roon to see what your thoughts are.  I'd be curious to what you hear.

I hadn’t considered that Roon software could be an issue, except when playing with DSP. If I raise a frequency band really high, say 70db, just to see what happens, the result is bad distortion, but I don’t know if that’s because I was overloading the USB input to my DAC. DSP aside, I don’t see how there could be degradation. Red book CD all the way through double rate DSD all sound very good generally, depending on the recording, with DSD sounding the most natural. But even DSD doesn’t quite match the best of my LPs, played on my VPI Classic 4 with Kiseki Purpleheart mounted to an SME 312s to a Pass XP 17.