Guitar pre-amp question

Most pre amps have a gain nob you can turn. If you share your specific preamp, I'll try to help more.

The user manual shows an input level nob on the left on the device. This didn't do the trick?

No, input level knob doesn't affect the amount of crunch in the pre-amp. It only makes a quiet input signal louder. This might be a terminology issue, Gain is not the same as Volume to me. Gain cranks whatever you're tinkering with (distortion, a frequency range, a transient peak, etc) and Volume makes the collective, final result louder. 
 
I think, in this context, Volume is used to mean Gain in the pre-amp section and Output is supposed to be the final volume.
 
 
 
 

gswitz:
 
The discussion at you link is a tad off target because it's about matching input and outputs with other gear and for specific purposes. My question was more about getting the amount of crunch you want on a particular guitar sound. If the preset increments (Low, Medium and High) are not quite doing it for you, what do you do?
 
The answer I think is to choose the closest setting, Low for example, and then add more crunch using the preamp Volume control. Roland, in this case, seem to be using Gain and Volume to mean the same thing. That was really the source of my confusion. It's an older unit and terminology probably didn't matter as much back then. The decision to call it Volume instead of Gain might have been a marketing decision, more people know what volume is!