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.

Okay, thanks for the clarifications. I have a couple of suggestions:

1) Try dropping the optical and using a coax SPDIF. While optical is theoretically better, the general consensus is that the implementation of optical is worse than coax digital. I'm guessing that it won't solve your problem, but it's super cheap and easy, so it's worth a shot.

2) Consider the Wyred 4 Sound DAC-2. I just got one a few weeks ago and the more I listen, the more I like it. You'll find a lot of other users on A'gon who like it, too. But in your case, it will be especially interesting because it has its own volume control (though you'll probably use the Sonos' volume control)... and HT bypass. So the W4S DAC would feed directly to your amp -- no Anthem in the circuit for music. For HT, the Anthem's R/L outs would go into the W4S, and pass through, unmodified to the amp. There are various ways to configure this, but in your case you'd use the Anthem's 12V trigger out to tell the W4S to go into bypass mode. For $1500, it's almost a no-brainer.

3. I'll re-recommend the Pace Car. It will work with the Sonos whether you use the Anthem, or get the W4S DAC-2. (The W4S DAC has USB input, too, so you could use it directly from your computer, dropping the Sonos from the system if you want.)

Your biggest, most noticeable improvement will probably come from the W4S DAC. They have a 30-day return policy with a 15% restocking fee, so it's a $225 experiment.

But you won't return it.