Tube Works Blue Tube Enhancer *******SOLD*********** Your BLUE TUBE is intended primarily for bass, keyboard and guitar players who desire to warm-up and enhance their sound by using the classic vacuum tube as the vehicle.The heart of the BLUE TUBE is the classic 12AX7A twin triode vacuum tube. It is possible to obtain many classic old amp sounds with your present solid-state and probably over-processed equipment. If you are using tube equipment, the BLUE TUBE will add even more to the good sound you already have! This pedal is one of the warmest tube pedals I have ever owned and I have owned two of them B.K Butler did a phenomenal job on his design this pedal reacts so well to different tubes right now I have a beautiful vintage Mullard 12AT7 installed. I chose the Mullard because it's low gain and has a warm fat sound I would keep the tube but it goes so well with this pedal I'm willing to let it go. I will also include three additional tubes a unbranded Chinese 12AX7 , a very nice Sylvania rebranded Baldwin 12AX7A and a nice Sovtek 12AX7 use these tubes if you desire higher gain all three tubes sound very good. Manual: http://www.genzbenz.com/img/manuals/tw/903UserManual.pdf Videos: The pedal is in great condition and works beautifully I'm only selling my baby because I have a Verellen Meatsmoke Pre coming. I purchased this pedal from the original owner and he removed the front two feet and attached velcro so it would fit on his board. I am selling this pedal plus the additional tubes for $95.00 which includes USPS shipping with tracking to the Conus and Canada at this time I'm not looking for trades thank you for looking.