●MANLEY input transformer with nickel laminations potted in mu-metal case. 3K Ohm input Z ●PHASE REVERSE switch for balanced XLR input ●Alternate transformerless 1/4“ HI-Z (5K Ohm) input ●BYPASS switch & AUTO-MUTE w/warmup delay ●Silent conductive plastic BOOST & CUT controls ●Sealed gold-contact Greyhill frequency select switches ●Vacuum Tubes:1 × 12AX7WA (gain) and 1 × 6414 (or 5965) White Follower ●Hi-current drive ＜50 Ohm LO-Z XLR & 1/4“ outputs ●Balanced Transformer-Coupled XLR Outputs via MANLEY 9611 ●Flat frequency response from 10Hz-70KHz ●＜0.01% THD @ 1kHz ●S/N Ratio:116 dB ●Adjustable FEEDBACK / GAIN:Unity ±5 dB ●Max. output:+30 dBv ●Power consumption:18 watts ●Operating mains voltage:Units are purpose built for original destination country's mains voltage: 100V, 120V, or 220-240VAC as indicated on the serial number badge. Power transformer must be replaced in order to change mains operating voltage. 120VAC units may NOT be rewired to put the primaries of the power transformer in series for 220-240V operation or a large radiated field of hum will develop. If changing locations/voltages, the power transformer must be replaced with the dedicated one for the voltage at which it will operate. ●Mains Voltage Frequency:50～60Hz ●Dimensions:19“ × 1 3/4“ × 10“ (occupies 1u) ●Shipping weight:12 lbs.