Turntable volume low?

I am very new to all this; not having anything like this since probably the 1980s.
I have a Pro-Ject Debut II turntable with an Ortofon cartridge. This is plugged in to my Auna VT tube amplifier via the aux inputs (correctly red to red, white to white) and playing through Wharfdale Diamond 9.1 speakers.
My phone plays well through the Bluetooth connection and my TV plays well through the optical connection. Yet the turntable sound is very quiet. It IS coming through the amp but so quiet even at full volume.
Anyone any ideas?

 

You need a phono stage!! Most sources are at "line level" which means usually 0.5 - 2V output but a phono cartridge gives about 0.005V so needs at least 100 x amplification before going into any "Aux" input, PLUS, records are cut with very low bass level and very loud treble for technical reasons and this is called RIAA equalisation. A phono stage also applies the opposite ie bass boost and treble cut to result in the correct balance through your speakers.

 

Perfect; thank you.
Ordered one.