Croft specs - too much gain?

[Wegamus]

There is another option with Croft gear, one that Glenn offers.

The output/line stage of the 25R (and other models) can be converted to a zero gain buffer (cathode follower). This removes the gain given by this stage normally and will allow further travel on the volume pots.

I have modified a Croft pre into this configuration previously.

But will that stop the hiss? Is it the preamp gain that’s likely causing it?