Compressed v uncompressed with turntable

I'm not quite I understand your question.

First, it should be the opposite in your first paragraph. Uncompressed has the greatest chance, given a poor local wifi environment, to have dropouts Most people fix that by changing to to Compressed.

But your second question also doesn't make any sense. The act of setting Compressed on the line in only has an effect on the data coming in on that particular line in. Once the data is in the Sonos ecosystem, it no longer gets modified.

Slightly off topic but what does compressed actually do to the inbound signal?

I believe it does two things. 1) Compress it slightly (but no idea how much), and 2) adds a significant amount (maybe 2 seconds) of buffer time to ensure that there's enough bandwidth and time to get the entire signal sync'd across all speakers....even if there are no other speakers, it's a function of the software, not dependent on how many speakers are actually connected.

Oops uncompressed stutters compressed is fine

In regard to my second question

Before I had Sonos connect I had turntable into preamp then into amplifier with separate speakers connected to amplifier

I now have the connect between preamp and amplifier so was asking when I play on this set up what difference is the sonos connect making with compressed audio

In reality I hear little difference but was just curious as whether compression was only applied when streaming to other sonos devices

Fergin