I plugged the b3k into my gk 800rb and ampeg 8x10 using my Spector... It was cool but I feel its too fuzzy for me. I had the blend and level about 12 and drive about 11. I did experiment, still not it for me. Guess it goes on the shelf. One other thing, I was using my sansamp power supply (9v) and it the gain got really noisy past 11 I switched to a boss and it was very quiet. I'd still prefer a battery since I'm not using a pedalboard these days
I have a Spector as well. I learnt that it overloads almost every pedal (apart from compressors which have internal voltage pump). It is not so much about strong signal but rather about output impedance. When using effects, I can't live without a booster at the begging of the chain which can lower the signal. In my case it is SFX Micro Boost.