The gain is adjustable in eight steps, with up to 75dB of gain at the maximum setting. Nine different cartridge loadings are provided.http://www.theabsolutesound.com/articles/tas-196-aesthetix-rhea-signature-phonostage-1/
I doubt you need of a SUT with 75db gain. My cart is .24 mv output and my phono pre (JLTi) is 62db gain which has plenty of output. Check your settings if you haven't already.