A buffer/booster housed in a miniature aluminum chassis, featuring a JJ Electronic 12AU7 (ECC82) tube and operating at an internal voltage of 100V. When the volume is set to Min, it functions as a buffer; increasing the volume from Min automatically activates the booster circuit (up to +20dB, 10x gain). Power supply: DC 9-10V. Current consumption is approximately 350mA maximum, so a power supply of 400mA or more is recommended for headroom. Compared to the 12AX7BB, it has less distortion and a wider, hi-fi sound. It's highly regarded for use with electric guitars, as well as electric basses and acoustic-electric guitars. - Model: Lee Custom Amplifier 12AU7BB - Included: Main unit, outer box, instruction manual Purchased new one year ago and used 4-5 times in the studio.