For a fuzz sound, I set the gain pretty high (3 o'clock or more), no filtering, and scoop the mids pretty severely (9 o'clock or less) at 250 Hz. I'll also boost the highs (2 o'clock) and lows (1 o'clock). I like this as-is, but you can add the OD channel at low or minimum gain for a "clean" blend, volumes to taste.
How are you setting the DIP switches inside the unit? Because you can only get 2 modes of effects, A or B, you'd have to combine two of the effects.
Well, the first thing you have to understand is that I use it for both guitar and bass. It's my main guitar dirt, but my B7K is my main bass dirt (with the Multridrive and ODB-3 as additional options by themselves or to push the B7K). So for guitar, I have one channel set to just OD, and the other channel set to all three (where I'm usually mixing the OD and distortion with the fuzz off). However, I've been thinking of switching this to just OD and fuzz on one channel, then just distortion on the other. This might be just as good for my guitar---I don't need to mix OD and distortion, so I could switch between OD and distortion, or I could use the fuzz and switch between two higher gain options. For bass, this would give me a lot of options. I could use the OD/fuzz for fuzz, blended or not, and the distortion channel as an all purpose channel unblended channel that covers OD and distortion---the "mild" distortion switch is basically like the OD, so I could use it different ways.
Lately I've been setting up the dip switches for Overdrive and Distortion on preset 1, and Fuzz only on preset 2. I've always loved this pedal, it has the O.D. sounds I've always longed for, and for me with the addition of a blend (Mosquite Blender) it's even better in that I don't have to use one of the channels for a blend. The Fuzz in the Multidrive for me is even better than the MXR bass fuzz deluxe that I had on my board before.
I do like the fuzz sound a lot. I've been looking for a fuzz but some days I wonder if I already have it. I don't like the fact I have to dedicate a channel if I want a blend, and I would rather not get an entire dedicated blender. However, I don't always feel it needs to be blended. Low end loss is minimal, and you have the EQ to account for it anyway. I really need to experiment with it more getting the right OD sound. I haven't tried too much with it because I have a B7K and an ODB-3. I've been looking to dump the ODB-3, though, and if I could get it to play nicely with the B7K for a nice OD sound, that would be fantastic.