If you are prone to believe things like inputs make a difference, Sonos is not for you.   Try Naim, they are built for those who think the “quality” of a simple conductor of electrons can actually affect digital or analog audio. 

Well, I am prone to notice the difference between CD quality and...tape cassette quality? Again, I’m heavily invested in Sonos and love the products otherwise - just want a way to pass a lossless signal from my turntable (or lossless audio recordings) to my Sonos speakers, which are advertised as being able to handle lossless. Thats one of the major benefits of wifi over bluetooth, is its ability to handle lossless audio.

The Line-In on the Sonos Port is lossless when set to uncompressed and fixed volume.  There will be no differences from the analog audio in to the analog audio out. 

At very best, the input on the Amp is downgraded to CD quality - that is not lossless. Also, see this:

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-sonos-amp.6957/

I’m one of the ‘turntable folks’ he mentions in his review of the amp. 

One specific question: have you tried listening to an analogue source connected to the Line-In? I ask, because I have a CD player connected to mine that way and to me it sounds good. Perhaps my ears are not accurate enough, but I can’t hear any shortcomings.

I’m normally a fan of the Audio Science Review articles, but this doesn’t seem to be a very good one. For example he seems to criticise the mains socket as a “proprietary connection” when actually it is just a standard IEC type C7 plug and socket?

I’m impressed with mine - I think you would probably find the quality of the Line-In on an Amp or a Port perfectly adequate in terms of sound quality when using a turntable as a source, provided you use it with an appropriate good quality pre-amp (Edit: actually it looks as though the Music Hall products mostly have built-in preamps, so you probably won;t need the latter).

This is mumbo jumbo.  I am assuming that your turntable outputs an analog signal, for which the term “lossless” has no meaning.  The Amp / Port receives this and converts it to digital format to distribute round the Sonos system.  Each Sonos speaker will convert it back to analog to be amplified and output as music.  There is no perceptible loss of quality in this process.  Where there IS a significant loss of audio quality is in the vinyl being pressed from the digital master and then the sound being liberated by the application of a needle.

To address your main point….. Sonos does a perfectly good job with turntables.  But analog media is an add-on, not a core feature.  Sonos is fundamentally about digital music.  Always has been and always will be.  Don’t expect some sea-change in how your turntable sounds through Sonos, it’s not needed acoustically or commercially.  If your vinyl doesn’t sound as good to you as you think it should (does it?), I don’t think the “quality of the inputs” is the place to look for a reason.

Even in a good audio lab with a double-blind evaluation set up folks have not been able to consistently identify CD quality sound from (the advertising and revenue generating) HD and better versions.

If I had the option here I’d set my Sonos to never fetch anything higher quality than CD standard unless it was Dolby Surround or Atmos. Clogs up the WiFi and internal buffers for no audible gain.

As an expert (in the distant past) turntable user and setup technician I’d blame any audio issues coming from a turntable on a small set of things.

1. Improperly set up cartridge and tone arm. Several critical settings most folks ignore, they get the wires wrong too.
2. A worn, dirty or damaged record. Sometimes you can work around that with a  good cleaning or different shape of stylus.
3. Junk turntable, wow, flutter and rumble (bad bearings or drive) are the most common. A poor tone arm will also have issues with warped records that a quality one would play well.

Outside the turntable a missing, bad or incorrectly set preamp is common. Not so common would be bad cables. I’ve never seen a bad input jack but it could happen.

Buuuuut, not all DAC’s are equal, correct? So if the Port/Amp does a crappy job converting the signal from analog to digital, then no matter how high a quality turntable/cables/pressing you have, the sound won’t be any better than what you might hear over broadcast radio, no? I’m clearly not an expert and maybe not an audiophile, but I can hear a difference when my turntable was hooked up directly to analog gear in the past. Still, as it sounds like there aren’t any options (besides the Pro-Ject T2W and the Victrola Stream models), I’ll give it a try!

It’s true. They are not, but - as already said - the inaccuracies introduced by the process of making a vinyl-based recording and playing it back are likely to completely overwhelm any inaccuracies added by the D-A and A-D conversions.

I’m pretty sure you will be happy with the result, based on my experience using a CD as the source. Ideally you should try to have a setup which allows you to listen to the output from the turntable’s preamp entirely in the analogue domain, so that you can compare it with what you are hearing via the Amp. That way, if you hear something that you don’t like, you will be able to figure out whether the source of the problem is within the turntable/preamp or within the Sonos part of the system.

CDs aren't lossless?  Where are you getting your science from?  For all audible frequencies and a little beyond, CDs are perfectly lossless.  

I am wiling to give it a try.. My Music Hall doesn’t have a phono stage, so I’d have to get one in addition to the Amp. I may just purchase the T2W from Pro-Ject as well and do a side-by-side comparison. According to the Pro-Ject site, it will send a lossless signal to Sonos speakers. Going back to my first post, if you’re reading this Sonos people, if you could just add a nice phono stage and large touchscreen to the Amp, I think you;d have a home run, but I’m probably not the usual Sonos customer I’m guessing.

All DAC chips, even the most expensive, are commodities costing under $10.  There's nothing special about a transparent DAC, and if a DAC sounds different, it's coloring the music, which makes it a bad DAC, not a good one. 

So, you’re saying the DAC in the Sonos Port/Amp, is the same quality signal as the DAC in a McIntosh or a Lynn amp?

Also, watch this at minute 11:00:

https://darko.audio/?s=Sonos+amp

​@Radionick .  I am not clear what you are trying to achieve here.  If you want audio that sounds as close to the original master as possible  - the sound that the artist, producer and sound engineer intended, with no loss - then just stream everything. If you like the sound of vinyl, then what you like are the imperfections introduced by this medium.  That’s absolutely fine.  But to then get hung up on whether the DAC in a Port is as good as another DAC is (if you will forgive my saying so) just plain daft.

And up to now I have forgotten to mention one other thing. When, like me, you have passed your 60th birthday, the greatest loss of audio quality occurs after the audio has left the speakers :(

The chip performs the same.  Truly transparent DAC chips are pennies on the dollar and perform the same as any other transparent DAC.  The technology has been around for many decades, and the math involved is 100+ years old, it has long ago been commoditized.  So the only way a DAC could be different is if it is coloring the sound, something you do not want it to do if you are a true audiophile.

Now wars have been fought over what the rest of the assembly does to the sound quality, but that’s the old subjective vs. objective argument that can never be proven (except by standard A/B/X tests that subjectivists will never accept and actual scientists use to prove things every day). 

​@Radionick watch this video for a lesson on sampling.  It explains how the ADC → DAC conversion works.  It shows how nothing in the original analog under ½ the sample rate is lost, and since the CD sample rate is 44.1 or 48 KHz, nothing is lost under the threshold of hearing (max is 20 KHz) when sampling at CD rates.  The narrator is Monty Montgomery from Xiph, the organization who created the FLAC codec.

In short, the jaggy stairstep representation of sampling used by unscrupulous music and hardware manufacturers to sell the “benefits” of greater than CD sampling rates is complete bunk.

There can be some sonic differences created by PC board layouts using the same parts. In my teens I built a microphone preamp. In a few weeks I needed a second unit. In the interim I had been reading about PC board layouts. The new preamp sounded better than the former, even though I was using the same circuit and parts. I’m not claiming that the difference was night and day, nor was I surrounded by cheers of accomplishment, but I noticed an improvement.

I cannot locate it at the moment, but some years ago there was a research project that gave a few engineering teams the same bag of parts asking that the teams build a power amplifier. The results varied — both listening and measured.

Layout, power and grounding issues have bitten more circuit designers that not.

Back in my day: The pretty printed on paper version works perfectly - in theory. The first design won’t work at all. The second has various noise issues. Third has inter-modulation problems. If you don’ reintroduce any problems when fixing the next ones you might be ready to order more than one board.

Today the computer makes it all faster and the rapid board fab machines reduce turn-around times but nobody has come up with a flawless layout tool, they are getting really close on the digital side but analog is still partly art and skill.

Chips, well look at the spec sheets and the differences are plain to see. Translating the specs to audible differences is a bit more work but in the end all but the cheapest junk DAC or ADC chip is better than your ears.