Tekton Double Impacts

@evolvist and @bullitt5094  Great to hear Bullitt's system is coming together. Looking forward to hearing more about the SEs once they are fully run-in.

@vitop  I'm pleased with the NAD M27. And it is frustrating that it is sitting idle while I wait for my HT system to take shape. Like you, I've been impressed with it's reviews and performance in my system. And like you, I will probably have the Anthem AVM 60 in front of it. But I wouldn't choose it as my go to amp for 2ch, as long as I had choices. For that, I have a very clear lean towards Class A/B and now finally a Class A amp in the Pass XA30.8.  Your response to 333Jeffery made me think it would be good to get it back in system and see how it does, now that my system is more 'mature' and better dialed in than it was when I had just received the Double Impacts.

Just for the record, I have nothing against Class D amps. In fact, I have nothing against anything in the audio world unless the sound turns me off. 

Evolvist, the Ulfs now have over 100 hours on them, and they are still breaking-in. If I had to call it right now, I would say the DI's get you 75% of the way to the Ulfberhts. But this can change as I put more hours on them. I am using the Yggy dac, and it seems to pair well with the Tektons. One thing I can say for sure about the Ulfs is that they respond very enthusiastically to power, much more so than the DIs. My dad put this to the test by playing some of his classical piano cds through them, and cranking up the volume to thunderous levels. I'm talking heavy metal concert levels!  The Ulfs didn't once strain/distort/compromise the sound quality. The piano sounded amazing, almost like having a concert grand in the room with us.

David: What is the difference that you can hear between the M27 and the class A/B or even class A? Quieter background, more sound spectrum, dynamics or exactly what? Clean sound should be clean sound no matter what it is playing. If the M27 does not sound as well on music as the class A/B or class A, then I can't believe that it would sound as good on HT either. I plan on running music through mine also.

@vitop  

It's a very good question. And I plan to find out much more specifically, when I bring the M27 back in. It will be a good test for me.

These things / differences are about preferences and experiences. And they uniquely become more about us than uniquely about the electronic component. 

I also come from having a tube based system and bias when I was seriously into 2ch audio circa 2006 to 2012. Since then, until this April, I have had a major holiday from 2ch.  In this now current iteration I've decided to go solid state. For now. : )

I'll try to answer your question, but I apologize in advance if what I share is not satisfactory. First off, I'll say that each of these amps has a 'signature' to its sound re-production via the DIs that my ears differentiate over longer listening periods with each amp. These are not serious nor negative differences, but differences nonetheless. If I only had a single amp, I'd be happy accepting any one of them. They are all good enough for my needs. BUT, AND THIS IS IMPORTANT, I also accept that there are better amps (to my ears) available than what I have.

I spent more time comparing the Moon Neo 330A and the SST SoA mk2, which are both class A/B (and not the M27 since it's multi-channel and is planned for HT) when I first got the DIs.  I realized that the SST was ultimately preferable (and this was after initially preferring the Moon) and it was mainly because it was 'warmer,' with more body than the Moon Neo and I liked how the musical 'energy' was portrayed by the SST. As I've tweaked and upgraded my system, the SST has been able to keep up and showcase the changes along with the DIs and the rest of the chain.

In terms of the M27, I'm going from memory from about 4 months ago, when my system was just being re-built. I'd say that it boils down to my musical and emotional response, with the other amps delivering more of the connection to the music and artists that's important to me. If it was the only amp I had, despite the extra channels, I'd be happy listening to 2ch or to a hybrid 2ch/HT system via this amp.

Once you get your Tektons in, play with different amps...perhaps some local audio buddies can bring their amps over...I understand @evolvist  loves to travel with his! : )

I'd also be happy to send the SST to you, when you have your system setup and dialed in for you to compare with your M27, driving the main L/R channels.