Era 100 with Turntable humming

@JoshSyd 

First of all please check if your turntable in fact is set to line out. Usually there is a (sometimes hidden) switch to choose between phono out or line out. 
Next important thing is to use the original Sonos audio to usb c adapter to connect any line in signal to the Era 100. 

And to ensure the turntable is properly grounded, something Sonos doesn’t provide. 

@Schlumpf    I’m using phono out, and I’m using the authentic Sonos line in which is connected to an aux to red white. 

to my knowledge there isn’t an alternative to the line in anyway 

@Airgetlam yeah this is what I think the issue is. I’m wondering if there is an alternative where I can connect the grounding cable to the turntable and the other end to something else? I’m really not sure how it works 

In this connection scheme you should be using the turntable’s Line mode --- unless you are using an external preamplifier.

@buzz sorry I think I’m mistaken, I’m not home but i know I’m using the correct one as I tried the other and it doesn’t provide any output at all. If the line out is correct that’s the one I’m using. I have no external amp 

As a test, try physically moving things. Amplifiers, powered speakers, TV, and power supplies near the turntable cartridge can cause hum issues, but powering down and small physical movements of these items will change the character of the hum -- if this is an issue.