[Darryl Ramm]

Lots more details needed… What does “not enough gain to get a good recording” mean? … What input Level, dBFS do you get? How are you telling the Shelford is “almost hitting peak”? What gain settings is on the Shelford? Are you testing with no filter, no eq, and no compressor?

What mic? How exactly do you have everything connected? What exact output, exact input, connected by what exact cable?

You should be going out the XLR line output into one of the Line In TRS inputs, are you using a correctly wired balanced XLR to TRS cable? (Check with a multimeter).

You can also do stuff like use signal gen driving an Omni output to drive the preamp and confirm its gain. Check the VU output meter makes sense with the Pro Tools input level etc.