Hi @Nick Slater,
Thanks for reaching out to the Sonos community and for letting us know about your concern. Let me share some information to help you out. Sonos Connect has a set of analog RCA outputs that allow you to connect the other end to an RCA input on your amplifier or receiver. We don’t have much information about using mini amplifiers but we don't limit our customers to using or trying other options. However, we won't be able to guarantee compatibility. It may or may not work with Sonos.
We can wait for suggestions and feedback from our Sonos community members, they might provide their inputs about this. Please let us know if you have any further questions or concerns, we’ll be glad to assist you.