What should my next upgrade be? Your best experience

Totally agree with implementing room treatment and system setup prior to changing equipment. Then upgrading the DAc and streaming system.

 

Teh nice thing about room treatment can mean a well placed quilt or two on the wall, a couple of large plants (real or fake) in between teh speakers or in the corners of the room.  Lot's of inexpensive and nice looking elements that will help the sound of the room.  Also a rug in front of the speakers if you don't have carpet is most probably a need too.  Just thoughts.

Garbage in garbage out.  Start with upgrading the source not the output.  You listen to digital so make it better.  The Sonos upgrade feeding an outboard DAC will make your speakers sound better.  Digital components are very sensitive to AC power gremlins.  A better power conditioner should help clean up the digital signals.  If you can get a dealer to allow you to demo a Denali you will be amazed,

I am not convinced about the Sonos' inferiority. You produce no data to substantiate that its output would be garbage. Also, there is as yet no solid evidence that the difference with the sound from the Marantz is due to a problem with the Sonos, even if it is obvious that the Marantz is very good. Rather than buy yet another DAC when you already have an excellent one in the Marantz, the simplest solution would be to direct the digital output from the Sonos to the network connected Marantz (but it may be tricky getting that to work). Also, I am not so convinced that digital components have particular power supply isues if they are well designed.

It all depends on what your budget is and what level you are able and want to play on.  Digital is highly sensitive to power issues.  It doesn't matter if it's a 500 Chord Mojo (I own one) that's battery run or my Ayre QX5 that has a power conditioner built into it and has built in optical isolation etc....  I have friends who own the Bricasti DAC/amp as well as the Davinci mk 2.....all of them need the proper filtering and power cord.  Digital still has inherent problems and that's why a decent TT combo will still sound more musical and more natural than any digital out there.  There are some areas where digital can be outstanding and with better clocking and design, they are getting jitter to where it needs to be so timing isn't off as much.  

There are outstanding value DACs as well as good sources, but you must try them all together.  Digital is so finicky.  You can't just say source A is great for the money and DAC A is also great for the money and assume they can sound good together.  Too many things will play into that like your rooms power, connections between the two, the way they both are engineered and which connections are max'd by each product.  Then you take into account your wifi if you stream that way (hard wired is always best), which ethernet cable are you using and what type of isolation are you using if any, both internally or externally.

Just too many variables in play here.  I personally buy systems.  That's what I'v always done and I usually don't buy that often.  I will make some changes if I feel they are worth the money and if I have the money at the time (just upgraded from Vandy Treo's to Quatro CT as I felt they were THAT much better for me).  

When I help someone put together a system, I usually take the budget and figure out the best source for them and then look at speakers they may like to get an idea and then fill in with the amplification.  Pre amps to me are SOOOO important.  

Garbage in = garbage out is true, but a great source can be ruined by a DAC, amplification, mods, accessories, cables and or speakers.  Same with anything else in the chain that is down stream.  That's why so many folks audition speakers and fill in from there.  I've heard better sound, personally, from GREAT speakers, good amplification and a decent source. Conversely, I've heard not so great sound from a wonderful source feeding world class amps run through average speakers.  Again, JMHO