A newer DAC will deliver more detail and better imaging/focus.
However, the jitter from the Sonos is something that should be addressed first. If you don't have a low jitter source, the DAC will not make that much of a difference. Many use the Synchro-Mesh to reclock the Sonos digital outputs to lower the jitter. Synchro-Mesh also provides galvanic isolation on input and output, so eliminates the ground loop from Sonos to DAC.
The dac chip in the Cal Audio Sigma II is an old Cirrus Logic Delta Sigma, in my opinion not worth hanging on to.
If you play pcm "redbook cd flac files" as you said, then you should go with a R2R Multibit type dac, look at the Schiit Yaggdrasil.
Thanks for the input. I realize the C712 is a weak link but I am someone who cannot live without tone controls, in this case the loudness knob. I have been considering a C46 due to the 8 band EQ but I'm not sure how much of an upgrade it would be. The C712 also has some sentimental value because I am the original owner since 1993 and it was my first decent piece of gear.
Still very good for pcm "redbook cd flac files" if you can’t stretch to the Yaggdrasil.
Schiit make very good stuff at great prices, without "glitzing" them up with expensive chassis and charging a fortune for something that doesn’t improve the sound.
Remember Mike Moffat owner of Schiit, used to be head designer for Theta Digital when they were on top of digital replay, so he should know his Schiit.
FWIW I have a Schiit Bifrost Uber and I really like Schiit gear. Having said that, I have bought a Bluesound Node 2 this year and I play digital files from my HDD via my wireless router to the Node 2, mostly ripped CDs. The DAC inside the Node 2 sounds as good as the Schiit DAC on at least half of my files and better on the other half. With MQA files via Tidal streaming the internal Node 2 DAC is noticeable better than my Schiit DAC. I have tried both DACs. The kicker is that the Node 2 cost me $499.
I really appreciate all of the feedback! I don't post on here lightly as I know how many are annoyed at those who can't even perform a simple Google search. For now, I've listed my Sigma II for sale and plan on acquiring a Schitt BiFrost MutiDac. The reviews seem generally positive and it fits my limited budget and the source material I listen to. I was floored when I dug out my sales receipt for the Sigma II and realized I've owned this DAC for 17 years. I'm 44 years old and this was my 2nd outboard after one of those cheap Audio Alchemy $150 jobs back in the late 90s. I think the BiFrost will get me by for the next couple of years until I have no more nanny payments and then maybe I can afford something along the lines of the Yggdrasill. Now I just need to figure a reasonable upgrade to the C712. I so wish someone offered a reasonably priced basic tube preamp with nice tone controls.
I so wish someone offered a reasonably priced basic tube preamp with nice tone controls.Again Schiit's your schiit.
While you get the Bitfrost tryout the Loki some here say it's a very good tone control: http://www.schiit.com/products/loki
And a simple pre the Mani http://www.schiit.com/products/saga
Or for more versatility pre the Freya, http://www.schiit.com/products/freya
I ended up getting a Schiit Bifrost multibit DAC and liked it so much that a week later I ordered a Freya line stage with the Loki mini for tone controls. The Freya was very harsh at first but settling in nicely now. I've just ordered some new Tung Sol 6SN7s which should hopefully improve it even more. I think this will keep me happy for awhile. Now I just need them to release the big brother to the Loki so I can run balanced cables as the Loki sits in between the DAC and the line stage. As it stands right now, I have no tone controls for my turntable or phono stage since I was using the phono stage built into the Mac preamp. The build quality of the Schiit products is pretty good considering the price point. I realize a lot of features are excluded to keep the prices down but it would be nice to be able to dim the LED lights and have a light on the volume knob to see its position. Other than that, the only dislike is the loud clicking of the attenuated volume control.