If you’re experiencing a loud undulating hum coming out of your Sonos Five speaker which is connected via line-in cable to a turntable with a built-in pre-amp and is happening only when playing vinyl and is more noticeable in the run off of that vinyl, it’s because these two items should not be in such close proximity to each other and need to be separated by a distance of at least 2 feet apart to remedy that.
This happened to me recently with my setup and I couldn’t understand why until I did a bit of research, not just here on this community but on other forums and sites such as reddit. What I learned was apparently the transformer and the emanating magnetic field in each item was causing a feedback loop when placed within a foot of each other and would increase whenever I would try to increase the volume settings using the Sonos app on my phone. Now that the increased separation has been implemented, no more hum and I can now initiate more volume and wow, the quality of sound is so much better than it ever was.
Anyways, I’d thought I would share in case others were experiencing similar problems. I’m not sure if this solve would apply to phono setups if indeed such setup would have apply here. I posted this problem in reply to the original poster (Sofaman4u) in another topic who had a similar problem which was part 1 essentially and I wanted to post my solve in that topic but couldn’t as the topic is now closed for additional comments hence this sequel topic part deux ;-)
Plus I wanted to do a big shout out and thanks to the guys who did respond to my problem and also apologize for misleading them on my initial setup. I recently found out I do have a built-in pre-amp in my Audio Technical turntable when I said I didn’t have one (duh!). Anyways, thank you to Airgetlam, buzz, Stanley_4 for responding to me and an honorable mention to GuitarSuperstar for responding to the original poster - you guys are the bestest! I think buzz was the guy who got closest with his possible solve to my issue which I later discovered. Thanks again :-)