BK Butler Real Tube

Name: BK Butler Real Tube
Brand: Tube Works
Availability: OnlineOnly

Overdrive

Boost

Tube

12AX7 tube overdrive with added midrange control—Gilmour and Satriani workhorse, 1987-1997.

Designed by BK Butler in 1986 after leaving Dean Markley, the Real Tube 901 improved upon his original Tube Driver by adding a dedicated midrange control to the circuit. Like the Tube Driver, it uses an op-amp driving a 12AX7 preamp tube, but the 5-knob layout (Drive, Output, High, Mid, Low) provided greater tonal flexibility. Manufactured in Denver, Colorado from 1987 until Genz Benz acquired the brand in the late 1990s (shifting production to Taiwan).

The Real Tube delivers moderate overdrive to fuzzy distortion depending on gain settings and tube selection. Without true bypass, it colors the signal path even when disengaged. The AC-powered design uses an internal transformer rather than standard 9V DC, which can introduce hum in certain setups but enables the high voltage needed for the tube.

Used extensively by David Gilmour, Eric Johnson, and Joe Satriani. A gold-anodized limited edition appeared around 1997. Butler later released lower-gain variants like the Blue Tube Enhancer (903) and Smooth Pick (303) using the same circuit topology.