SimAudio Moon North Collection

What a timely thread! I’ve been a fan of the Simaudio Moon amps for a while traversing from the 330a, 760a, and 860a-v2; I’ve been demoing at home the 641 and 681 components and have been extremely pleased with the design direction they have taken, and results achieved, with the new North series. The 641 stereo integrated amplifier is a marvelous amp. I can’t praise it enough. I have had a coda csib, which is another stellar overachiever. IMHO, I believe the 641 is next level, pretty much across the board. The 641 has an uncanny ability to generate a “detached from electronics” kind of tone; music springs forth in a buoyant and round manner, full of color and vitality. I honestly don’t know how they engineered such an organic and beautiful rendering of sound, as I’m hearing with this amp. The top end is truly exquisite at this price point and from my experience as good as any amp I’ve ever heard in my home systems. I can’t say the same thing about the 860av2, however, as I felt that amp was too stark, too hard-edged, too cool. There was something about it I was not able to get to sound right to me, despite cable swaps, source swaps etc. The new north amp signature is different, it definitely possesses the core signature of the later generation of moon amps- lucidity, clarity, focus, accuracy, speed, low noise, etc but it does so in a more engaging manner and fluidity-ness.
I strongly encourage listening to the 641 or 761 when you can.

I just heard the 761 amp with the 700 series streaming DAC preamp. It was playing on the Parasound Persona 9H. When I had previously heard the 860 v1 it was on the Parasound Persona 5F.

I spent over an hour listening to various tracks and I came away thinking that it was smoother and more detailed than the 860A v1. The Persona’s still had a bit of an edge to it, but it was much less with the 761. The BE drivers on the Persona have a bit of edge to them compared to my NS5000.

There was great detail without much irritation. The sound was projected out more than with other systems I have heard. I am not sure if that is because of the Persona or the amp. The slight irritation I got was from the Persona or the smallish room.

I use a CODA #16 with my Yamaha NS5000 speakers. The NS5000 has some 6th degree of separation lineage with the Persona lineup. I think the NS5000 have better drivers than the Persona. I think the 761 (or 861) would great on the NS5000 and I will likely replace my Sanders Magtech with one of the North Collection amps.

I can rotate the CODA #16 and the Sim amps around with the Magnepan LRS+ and the Yamaha NS5000 speakers. The Sanders is not great with the NS5000. I will keep the CODA #16 which is great with both speakers and slightly different sounding from the Sim. Compared to the #16 the 761 sounded a little cleaner on top and maybe more detailed. Ernie Isley’s guitar solo on Summer Breeze sounded better on the 761, more details which made it sound like I was there. The slight Class A warmth of the #16 is something that I also love. The Sim does not have much of that.

My only uncertainty was whether the 761 could drive the bass of the NS5000 as well as the CODA. The 9H has powered subs so I was not really taxing the 761 during the listen.

I went and heard the Luxman 10x amp for a short period at a dealer today. It was an improvement on the Luxman m900u for my ears. I liked the 900 a lot but thought it was too warm. The 10x is not as warm and a touch warmer than the SimAudio 761 that I heard last week. I loved both amps. Now I have a dilemma. 

I also heard a $100k CH amp that sounded really good. I was thinking this amp was the winner until I heard the price. I am not one to normally go for the most expensive gear, but this CH amp sounded great.

@yyzsantabarbara I’m amazed you’re able to hear the differences you describe between all these amplifiers when evaluating them at different times and in a context of different systems. 

The systems are different, but the sonic signature of an amp is rather easy to hear in a good system.

Are you talking about the Luxman m900u and the 10x? That was rather easy to hear with respect of the warmth of the amps. The speakers were Harbeth and Monitor Audio. Both were on the slightly warm side and not my preferred choices, but I adjusted to that. I am also going on memory of the m900u which I heard a few years ago with Harbeth. I almost bought the m900u. I did not because I did not think I could live with such as warm amp long-term.

If you are talking about the SimAudio 761 and the Luxman 10x that is a harder call since the Sim was playing on the brighter Paradigm Persona 9H which has powered bass drivers and really incredible DSP tuned base. I found the Luxman 10x warmer of the 2 and maybe a touch less detailed. However, the Persona is a detail monster and a bit bright; the Monitor Audio seemed a bit less detailed and warmer.

Given these system variables I am evaluating the Luxman and the Sim. My goal is to get a forever amp for my 2 systems. I already have the CODA #16 and evaluating other amps that are as good but sonically different. The Sim 761 is rather different from the #16. The Luxman is 10x not that much different.

I posted some more details on the Clarisys speakers that I heard at the shop that had the CH amp and the Luxman 10x. The Clarisys is a ribbon-based speaker that has some sonic resemblance to the RAAL 1995 Immanis headphone. I know the RAAL sound extremely well. So, the Clarisys demo gave me a good basis to compare with my #16 with the CH. I also own Magnepan LRS+ which the Clarisys also have some similarity too.

I have setup the RAAL headphones with my CODA #16 amp but that is not really relevant. The fact that they sounded sonically similar (maybe because of being ribbons) was the baseline. Not talking soundstage or imaging here.

I also get fatigued easy, which I found useful in evaluating gear. Funny thing is the worst demo (and most fatiguing) was with the Yamaha NS5000, the speaker I ended up buying and loving (I bought from another dealer).

On a side note, I am visiting my parents in Whitby, ON, Canada. There are 2 amazing hi-end stores cycling distance (10 min) on either side of town. I was able to sneak some audio listening sessions while visiting. I will be buying an amp from one of these Canadians if I get the Sim or Lux (almost certainly will).