Port Sound Quality

Sounds the same to my ears. I no longer own a connect to compare however. 
 

Are you using the digital out?

I using the RCA outs (the same as I did with the Connect).  

I can’t imagine that Sonos would replace a product with lesser components. Just doesn’t make good marketing sense. I replaced a Connect with a Port and while I can’t say that there was a significant increase in clarity I didn’t notice a reduction.

As a note… RCA is an analogy technology that components used can themselves degrade over time. I would suggest upgrading the RCA cables to new. Also, unlike digital cables there is a difference in analog cable quality. 

With digital cables such as HDMI for example either the signal is transmitted correctly or it isn’t. Spending more than $50 on a 18GB HDMI cable IMO is money not well spent. In truth $50 is probably an unnecessary upper limit expense. The major priority is a tight connection. 

The best RCA cables are Solid Core_Oxygen Free Copper (OFC) non-twist. Each strand is individually insulated up to the connection point. These cables are generally priced around around $40 each on the low-end.

If you are using the same cable as before with the RCA out, and the connection is not loose the only way to get different sound is a defective Port.

Burn in periods are pyschological effects but they do not apply here in any case.

Are you sure you are not just getting influenced by what you read? Where does it say that there is a different sound when analog outputs are used, on variable setting?

Nobody said that about the RCA outputs. In fact this review suggested they were fine. 

The AK4490 DAC is well regarded, and I would say that the analog out quality is better than the old ZPx0/Connect.

I’ve seen a number of posts about the poor sound overall without regard to output.  

What Hi-Fi? said this:  

Unfortunately, however, the Port’s presentation is about as disorganised as a teenager’s bedroom. Nobody seems to know where their part comes in and how loud it should be, a combination of missed steps conspiring to confuse even the most seemingly straightforward arrangements. If your streamer cannot keep in time a constant 4/4 kick, control will rapidly slip from its grasp the more parts get planted on top.

That would be enough on its own, but perhaps worse is how uninterested the Port appears to be in whether you enjoy your music or not. Dynamic expression is poor and punch is so lacking you almost expect its corner to throw in the towel.

This is all the more frustrating because it represents a step back. The Port is cleaner and more detailed than its predecessor, but the Connect manages to tie music together and deliver it in a much more cohesive and engaging fashion.

It’s those latter talents that are most important, and the fact Sonos is asking its customers to spend more on a worse performing product is a real disappointment.

Using an external DAC is helpful, so if you have a decent one built into your amplifier, we’d suggest using the Port’s digital output – though we’d hesitate to suggest adding to the already significant cost by incorporating an outboard DAC.

I’m pretty sure I’m not getting influenced by what I read since I didn’t start reading until after I noticed the degradation of sound. 

And do a little research on burn-in.  I disagree that it’s psychological.  

I’m afraid I gave up on this kind of subjective stuff years ago, other than the fact that the words “cleaner and more detailed” suggest an improved THD+N, which is what one would hope for.

I do not continue conversations with people that take What HiFi seriously.

Given that publication’s apparent enthusiasm for MQA I have to agree.