You can certainly connect a turntable to any of the 851A's analogue inputs, however, if the amplifier does not have a built-in phono stage, you will require an external phono stage between the turntable and the amplifier.
A phono stage boosts the low output from a turntable to 'line level' to allow connection to an amplifier as well as ensuring a minimal amount of noise and distortion within the signal.
As the amplifier has no phono stage built in, it is also not fitted with a Turntable Earth. Our phono stages have an earth for this reason.
If you are using another manufacturer's phono stage that is not fitted with an earthing connection, you will need to consult with the turntable manufacturer for earthing options.
The Topaz SR10 and AM10 amplifiers are the only Cambridge Audio amplifiers which have a built-in phono stage.