DAC or Upgrade To MX150 From D2V??

I'm guessing that you are running SPDIF from the Sonos to the Anthem and using the Anthem's DAC? Also, you don't say if you are making use of any other features of the Anthem for your 2-channel system (e.g., the crossover, EQ, etc.) The answers could affect the advice people give you. Also, maybe you could define what you mean by "lackluster" audio.

In your situation, if I felt the Anthem was the weak link, I would get an external DAC. The Anthem can last you for years of great HT, but DAC technology is evolving so fast that you'll probably want to upgrade/update your DAC more frequently, and it's cheaper to do that than getting a new high-end pre/pro. And it is unlikely that the Anthem's DAC would be competitive with even a moderately priced outboard DAC. Upgrading to the Mcintosh seems unnecessary.

You might also consider either 1) a USB DAC that you can play directly from the computer (bypassing the Sonos), or 2) getting an SPDIF reclocker for the Sonos to feed your DAC. Empirical Audio makes a product called the Pace Car that can be linked to your Sonos (with some modification) to greatly reduce the jitter. I've heard a system with that setup, and it was impressive. You might even consider trying that first, and seeing how the Anthem DAC performs with a reclocked source. If you are still unsatisfied, there are a lot of good DACs out there with SPDIF inputs.

Clarify - is the sonos attached via digital or analog cable?

I'm using the SPDIF (optical) from the Sonos to the Anthem. For 2 channel, I've set the "music" setting so the Anthem does as little processing as possible to the original signal (no xover, etc). I've setup my ARC (Anthem's Room Correction) targets to "flat" and 2 channel (FR & FL only). I've also tried not enabling ARC at all and bypassing every setting I could find -- to get as close to the source as possible.

When I say "lackluster" I'm comparing the 2 channel settings in the Anthem (using the internal DAC of the Anthem and as little interference as possible) with that of another preamp that I sold recently (unfortunately). The old preamp had a setting that was called "direct" where it bypassed a good amount of circuitry and tone functionality -- to get as clean a signal as possible to the amps. From my a/b comparison, the easiest I can sum it is: it appears that the Anthem "won't get out of the way". The bass response is subtly different and the high's are a bit harsh.

I've heard how good my amp and B&W main's can sound with certain source material from the Sonos' SPDIF on my old preamp, but for some reason the Anthem can't get as close. I've also tried using the analog out from the sonos to the Anthem, but it was terrible sounding -- just muddy all around. This wasn't surprising; I didn't expect the Sonos to have any decent analog out. I suppose the real crux of the question is if anyone has had good results with a good quality analog output (from any device) with the Anthem's 2 channel balanced input. My thought was that I'd buy a decent (under $2K) DAC and feed the Anthem with that for my 2.0 listening. Anthem claims the major cost difference between the D2V and the AVM50V is partly the analog section -- and that has a sort of "direct" feature. I'm just concerned about spending another $2K when I could probably just bite the bullet and sell the D2V and get the McIntosh MX150 (which in itself has some drawbacks such as a poor upgrade path and possibly not as good a 5.1 performance).

As a sidenote, I love the Anthem for 5.1. It's extremely good at cleaning up video and upscaling to 1080P. ARC does a solid job of also cleaning up my sub's response (a Velodyne HGS18). I just love it for 5.1.