Input Tube (each mono block): 1 x 12AT7EH large plate Eletcro-Harmonix Russian

Driver Tube (each mono block): 1 x 12BH7EH (or previously 6414)

Output Tubes (each mono block): 4 x EL84 Ships with Russian NOS EL84M (aka 6Pi14Pi-EB)

Output Tube Quiescent Standing Current: 25mA

Set Bias for 250mVDC measured across each 10 Ohm cathode resistor

Input Impedance: 110 kOhm

Negative Feedback: MIN= 3dB; STD=6dB; MAX=10dB of global NFB

Gain:

• FB MIN: 30.7 dB TRIODE; 32.1 dB UL

• FB STD: 28.5 dB TRIODE; 29.1 dB UL

• FB MAX: 26.1 dB TRIODE; 27.1 dB UL

Input Sensitivity for Maximum Output Power, defined as input voltage required in order to produce maximum power output reaching 1.5% THD @ 1KHz:

• FB MIN: 175mV TRIODE; 155mV UL

• FB STD: 312mV TRIODE; 340mV UL

• FB MAX: 480mV TRIODE; 566mV UL

• Input Sensitivity for 1W into 8 Ohms: 61mV 53mV

Maximum Output Power, defined as power output reaching 1.5% THD @ 1KHz:

• into 5 Ohms:

  • FB MIN: 18W TRIODE; 20W UL

  • FB STD: 27W TRIODE; 42W UL

  • FB MAX: 28W TRIODE; 46W UL

• into 8 Ohms:

  • FB MIN: 14W TRIODE; 24W UL

  • FB STD: 24W TRIODE; 40W UL

  • FB MAX: 25W TRIODE; 41W UL

Signal to Noise Ratio Ref. 1W: Typically 82 dB A-WGT 20-20K

Noise Floor: Typically 150µV = -74dBu A-WGT

Noise Floor: Typically 650µV = -62dBu unweighted

Will Scratch Your Floor: Use pennies under pointed feet to avoid marring cabinetry. Try quarters if you are in upper tax brackets. The bargain performer would be nickels. Paper currency does not function as well. Euro coins work 1.54 times better. Concrete pavers or wooden chopping blocks serve fine for amplifier platforms.

Dynamic Range: 83dB

THD+Noise @ 5W: less than 0.15%

Frequency Response at full power UL mode w/MAX NFB: 20 Hz to 20 kHz FLAT

Frequency Response at 5W into 5 Ohms: 10 Hz to 30 kHz FLAT, -3.75dB @ 100KHz

Recommended Speaker Load: Optimized for 5 Ohms

Output Impedance:

• FB MIN: 1.22 Ohms TRIODE; 1.35 Ohms UL

• FB STD: 0.80 Ohms TRIODE; 0.83 Ohms UL

• FB MAX: 0.54 Ohms TRIODE; 0.54 Ohms UL

Damping Factor:

• FB MIN: 4.10 TRIODE; 3.70 UL

• FB STD: 5.45 TRIODE; 4.78 UL

• FB MAX: 9.26 TRIODE; 9.26 UL

Power Consumption (idle): 102 Watts (0.85A @ 120VAC)

Maximum Power Consumption (at Full Power): 168 Watts (1.4A @ 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 ~ 60 Hz

Fuse type and ratings @ 117 VAC operation:
MAINS fuse: 3 Amp 3AG slow-blow use glass body Littlefuse Series 239

Fuse type and ratings @ 230 VAC operation:
MAINS fuse: 1.6 Amp 3AG slow-blow use glass body Littlefuse Series 239

B+ Fuse: MDA 400 mA SLO-BLO Ceramic Time-Delay fuse

Badge Illumination: Units produced before 3/2003 use 8V, 0.3A ”Fuse-Lamp” 1/4″ X 1 1/4″ – Serial numbers after MAHI036 use LED illumination which probably won’t burn out

Dimensions: 11″ deep x 10″ wide x 5″ tall

Shipping weight each: 18 pounds – noin 8,1kg