Link: uaudio.com [Owner's Manual] | soundonsound
LA-610 Specifications
Microphone Input Impedance: Selectable, 500 or 2kΩ
Balanced Line Input Impedance: 20kΩ
Hi-Z Input Impedance: Selectable, 2.2M or 47kΩ
Maximum Microphone Input Level: -8 dBu (2KΩ input Imp. & 15 dB Pad in)
Maximum Output Level: +20 dBu (120Vac line)
Internal Output Impedance: 80 Ω
Recommended Minimum Load: 600 Ω
Frequency Response: 20 Hz to 20 kHz +/- 0.5dB
Maximum Gain: 40 dB (Line), +77dB (Mic)
Noise Floor: -72 dBu 20 – 20kHz (Line In, Unity Gain)
Tube Complement: 3)12AX7, (1)12AT7A, (1)6AQ5
General:
Power Requirements: 115V / 230V operation
Dimensions: 3.5” vertical, 19” rack (2RU).
Weight: 12 lbs. (Boxed,14.5 lbs.)