Sonos Amp and Sonos One very quiet

Hello there 

I have a Sonos Amp and a number of Sonos Ones around the house. Whenever we play records in the house the volume on the Soho One is very quiet, relatively. By which I mean if you turn the volume way up it sounds fine, but then anything else played is super loud, and needs to be dialled back. 
 
This happens across all speakers and there are no apparent issues with the setup, cables and connections are all fine. The record player is a Audi-technical and has never given me issues 
 

Has anyone encountered this? Is this expected and just part of the setup, or is this something that with further investigations can be amended 

Thanks in advance for any assistance