the sbm1 should be run as wide open as possible. it adds a fixed amount of gain and then uses a resistor to reduce the amount of gain applied. the resistor can introduce some noise. so when run at 10, the resistor is essentially off, adding no noise. when the sbm1 is run at 3, the resistor is adding in a lot of noise. the v2 works on a similar technology with its gain knobs and trim pots. the trim pots act as a resistor. so it possible, get the gain set as close to the way you want it using the big knobs, with the trim pots set as wide open as you can.