Color: As shown Material: PC Description Report Item Details: Sugden SDA-1 amplification circuit The full DC line has no coupling or feedback capacitors, and the sound is transparent and pleasant to the ear Single operation JRC5534DD for core amplification The output stage adopts Class A design with 10mA Class A current All components Using 4 twin field tube inputs KOA hifi resistor 2mm thick printing plate, 70um thick copper Using American ALPHA soldering wire for welding Basic parameters: Size: 92 * 102mm Voltage: ± 12-17.5V Input impedance: 220K ohms AP test parameters: Output effective value: 11.0V Channel gain: 10.6dB 3.4 times Signal to noise ratio: 132.5dB is impressive Dynamic range: 133dB Channel crosstalk: -97dB THD distortion: 0.000092% very impressive THD+N distortion: 0.00027% Audio bandwidth: ± 0.039dB Color: As Shown Material: PC Package Contents: Preamplifier board x 1 (included potentiometer) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.