Please use a linear power supply, the ripple is small, and it is not easy to generate . Stereo audio two-way input four-way output, can directly push four headphones or external power amplifiers do not affect each other, power supply: DC5-19V, the magnification is about 5 times, the potentiometer controls the volume of each output separately. Using the high-current op amp NJM3414A from Japan , the maximum output current is 70ma, which can provide good large dynamic fidelity output.<br><br>colour:black Material:Metal size:128x53mm<br><br>Package Contents: 1 x Stereo Mixer<br><br>Only the above package content, other products are not included. Note: Light 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.