Operation confirmed. There is some crackling in the switches and knobs, but it does not affect use. It tends to disappear with use. It was used as permanent equipment in a non-smoking studio. Although it is old, it has been used infrequently. ■ Type: 2ch Tube Microphone Preamplifier / Line Driver / DI-BOX ■ Input/Output: Servo-balanced ■ Connectors: XLR, TRS phone ■ Microphone/line input with +48V phantom power ■ Ultra-wide bandwidth from 10Hz to 200kHz for an open sound ■ High-quality vacuum tubes built-in for a superb tube sound ■ Parametric EQ with adjustable center frequency, bandwidth, and level ■ Independent line driver for converting -10 dBV to +4 dBu pro level ■ Fully adjustable/switchable 12dB high-pass filter ■ Switchable phase inversion switch to correct phase issues ■ 12AX7 vacuum tube ■ Dimensions/Weight: 482.6W x 44.5H x 217D mm, 1U, 2.2kg