The SNAPPER Power Amplifier 4 x EL34 100 Watt Monoblock Features And Specifications: Input Impedance RCA: 475 Kohm Input Impedance XLR: 15 Kohm or 600 ohm switchable Input Sensitivity RCA: 750mV input = 110W output Input Sensitivity XLR @ 15Kohms: 1.5 V input = 110W output Input Sensitivity XLR @ 600ohms: 2.4 V input = 110W output (w/600ohm source) Gain RCA: factory set for 31 dB; Range = 29.5 to 34.5dB Gain XLR: factory set for 25 dB Negative Feedback: factory set for 9dB of global NFB Maximum Output Power into 5 ohms: 110 Watts (1.5% THD @ 1kHz) Maximum Output Power into 8 ohms: 100 Watts (1.5% THD @ 1kHz) Signal to Noise Ratio Ref. 1W: Typically 90 dB A-WGT 20-20K Noise Floor: Typically 105µV = -77dBu A-WGT Typically 388µV = -66dBu unweighted Dynamic Range: 98dB THD+noise @ 1W: less than 0.1% Frequency Response at 110W full power: 15 Hz to 40 kHz FLAT Frequency Response at 5W into 5 ohms: 10 Hz to 65 kHz FLAT, -3dB @ 100KHz Recommended Speaker Load: Optimized for 5 ohms Actual Output Impedance: 1.5 ohms Power Consumption (idle): 170 Watts (1.4A @120VAC) Power Consumption (at Full Power 110W): 336 Watts (2.8A @120VAC) Operating Mains Voltage: Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage. Operating Mains Voltage: changeable with power transformer re-wiring and fuse value change. Mains Voltage Frequency: 50~ 60Hz Input Vacuum Tube: 1 x 12AT7WA/ECC81 Ei Yugoslavian large plate Driver Vacuum Tube: 1 x 5687 NOS (was 7044 GE JAN NOS) Output Vacuum Tubes: 4 x EL34GT (JJ from Slovakia) B+ Voltage: 570V DC Output Tube Quiescent Standing Current: 30mA Set Bias for: 300mVDC measured across 10 ohm cathode resistor Lamp type: "FuseLamp" size 1/4" X 1 1/4", 12 volt, 0.15 amp; Units built after 5/2003 use white LEDs Fuse values & types for: 120VAC operation: MDL or MDA 4 AMP / 250 Volt SLO-BLO size 1/4" X 1 1/4" 240VAC operation: MDL or MDA 2 AMP/ 250 Volt SLO-BLO size 1/4" X 1 1/4" B+ FUSE: MDA 4/10th AMP, 250 Volt SLO-BLO CERAMIC BODY size 1/4" X 1 1/4" Dimensions: 15" deep x 13" wide x 8.75" tall Shipping weight each: 45 pounds Read the Owner's Manual