On a side note: I'm doing the occasional voiceover and a bit of music with my ancient analogue recorder and a while ago a top-notch engineer set the input gain of my microphone extremely low and instead increased the volume quite considerably via the volume control. This made the background hiss very noticeable. He then suggested to kill the noise in SoundForge with the noise reduction plugin.
He doesn't sound top notch to me!
Sorry, I don't mean to throw the guy under the bus, but really!
Gain should be set so the mic pre-amp does not clip.
There is always a compromise between lowest noise and least amount of clipping/overload.
I haven't worked in a recording studio for over 25 years......but that guideline never changes.