I just got my TTS 4 knob, I think George calls it the "Tone Monster", yesterday. this one has the 4th knob on top. My wife isn't feeling well, so my plans to sit in with a local band got nixed. Sounds really nice so far. I had a TP Hot and could never decide which of the low and high gain settings I liked best...this solves the problem. Amazingly, the bigger box with the jacks on the leading edge takes up less room than the std. Pedalworx small box with the jacks on the side!