Received the new Butler Tube Driver yesterday with the added Bias control. I caught BK's store on ebay at a good time when he was running a sale with the bias option discounted $50, the pedal was $374 shipped to my door with the bias upgrade. Intial impression, very unique overdrive. I can now see why the top players like Gilmour, Johnson and Satriani like the Tube Driver. The controls are all very interactive, once you get it dialed in, it is very sweet sounding. I set mine bias backed off to 3 o clock from full, Out level 7, High Eq 1 or 2 clicks from off, so about .5, Low eq 1 or 2, and Drive Level about 5. This gives me a nice juicey sound with vintage single coils or humbuckers. This pedal really shines for Lead work, bent or held notes with vibrato swell into a nice feedback overtone, like early Santana through my rockytop JTM45 combo with greenbacks. To my ear the pedal has a bit of a saggy definition with the bias control adjustments with a hint of a soft fuzz type character, a bit more of a TS midrange quality to the dirt. Pitch harmonics like the Rev Billy G, jump out very easily, also palm mutes really shine well with this pedal also I would say the added Bias control is a great upgrade for more tone shapes. This one is going to be a keeper for me and go on the board.