Thank you brilliant.Would normally say go for a gold plated adaptor, but your plugs aren't gold so this is all you really need:
You might prefer this type of alternative, though it could put a bit more strain on the Bose socket:Find many great new & used options and get the best deals for 20cm Twin 2x RCA Phono Female Sockets to Mini 3.5mm Male Jack Cable Audio Lead at the best online prices at eBay! Free delivery for many products.www.ebay.co.uk
If there's a 'Phono / Line' switch on the turntable, ensure it's on line.Find many great new & used options and get the best deals for 2 RCA Phono Female To 3.5mm Male AUX Stereo Jack Adapter Y-Splitter at the best online prices at eBay! Free delivery for many products!www.ebay.co.uk
Have you ever actually known anyone that's been confused by the term 'phono preamp'?It's often called a "phono stage" to avoid confusion.
There's quite a good explanation on https://www.cambridgeaudio.com/usa/en/blog/phono-stages