<p>AB400 dual channel professional stage amplifier board circuit design is and stable, the use of double differential input and increase the input signal processing, the push stage with a pair of 1930\/5171 and 5200\/1943 to do compound push, and then 16 tubes to do the power output stage, the output power up to 400W+400W.</p> <p>Great power, strong low frequency, rich details, the circuit adopts DC feedback design, good analytical power, good bass deep elasticity, stable work under high power, retracting and retracting freely.</p> <p>The board design has a perfect protection circuit, including switch delay protection, to prevent impact sound.</p> <p>Midpoint voltage protection, overcurrent protection, high temperature protection, and cooling fan interface.</p> <p> TTA1943\/TTC5200 audio tube, carefully matched after assembly.</p> <p>Model:AB400</p> <p>Output channel: 2.0 channel</p> <p>Magnification: 25x</p> <p>Power amplifier tube: TTA1943 x 8, TTC5200 x 8</p> <p>Frequency response range:20-20KHz</p> <p>Main voltage: DC dual 50V-110V, you need to add a rectifier board yourself</p> <p>Output power: 400W+400W\/4\u03A9, 200W+200W\/8\u03A9</p> <p>Total harmonic distortion: 0.01%</p> <p>Protection mechanism: overheating protection, overcurrent protection, midpoint voltage protection, power-on delay protection</p> <p>Size: 220 x 84 x 100mm</p> <p>Material: plastic+metal</p> <p>Color as shown</p> <p>Package Contents:</p> <p>1 x Amplifier board</p> <p>Only the above package content, other products are not included.</p> <p>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.</p>