What amp are you using? I have a Carver C-1000a (designed by Carver/Sunfire) and the pre-amp section does not have a very high output level, but the amp section is very sensitive to input. I suspect that the Sunfire pre-amps are designed to work best with Sunfire amps in a similar way. On the C-1000a I have to turn it to level 65 for good mid-level sound but going up to 75 or higher is quite loud. I think the dial maxes at 95 or so. It's more of a linear scale than inverse-exponential like the non-digital Carver pre-amps.