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Black Magic 20 Amplifier Specifications
Number of Line Inputs
1
Input Impedance
100K Ohms
Input Stage
12AX7 current sourced low noise valve
Automatic DC Restoration
Yes
Nominal Voltage Gain
26dB (into 8 ohms)
Output Stage Configuration
1 Complementary set of EL84M’s per channel
Regulated Screen Supply Voltage
340V
Output Tube Plate Voltage
408V
Output Tube Idle Power
Less than 9W each
Bias Adjustment
Automatic
Rated Power
20 watts per channel in stereo mode
40 watts in single channel mono mode
Output Impedance
4 to 16 ohms
Noise
Better than 100dB A weighted referenced into 20 watts
Hum
-100dB
Frequency Response
8 Hz to 40kHz (-3dB)
Full Power Bandwidth
26 Hz to 43 kHz without filters
Distortion
Less than 0.5%
Output Transformer
Interleaved windings, super wideband low leakage inductance design
Generator Source Impedance
1.5 ohms
Speaker Outputs
4-16 ohms each channel
Construction Method
Point-to-point hand wired axial and radial leaded components with star
grounds and no circuit board traces or de-plugable connectors
Components
High reliability wire wound and metal film resistors, metal polyester
capacitors in the audio signal paths
Dimensions/Weight
13” deep x 9” wide x 7” tall, 19 lbs per chassis
Color
Black with Silver Fleck and brushed silver trim compliments
Country of origin
USA
Warranty
7 years on amps (1 year on tubes)
