It's generally enough if you listen and watch with 60W Power amplifier board.Sound already very loud if half open sound Potentiometer for 2.1 computer speakers use. High and low tone adjustment. LoZ low impedance input, greatly suppress the noise. There will be not big noice if use general audio cable floating. High-power speakers recommended, the high power the better the effect. High efficiency, overheat protection.Power supply supports DC and AC, and DC is connected between any AC and GND (AC is positive). AC support Double 9V-Double 16V. is 9V-26V universal, the voltage can not be higher than 26V. Use TPA3110D2 chip, not refurbished domestic, the former op amp with two audio dedicated op amp NE5532, use fully sealed potentiometer, the cost is much higher than potentiometer, using a large number of high-frequency low-resistance chip , Greatly reducing the power supply resistance, chip capacitors are all multi-layer ceramic capacitors, internal resistance is minimal. The output terminal using the transmitter terminal, wiring will not be bad contact. XH2.54 & 3.5mm input, suitable for mobile phones, computers, CD players and other audio sources. 90% of the amplifier parts with all-chip lead-free environmentally friendly SMT production process, consistency is very good, a large number of stocks. Now widely used in high-end computer speakers Send three identical knobs (color send randomly, don't accept the specified color) PWM switching modulation technology, with LC low-pass filter to eliminate EMC, in line with FCC standards. All-digital PWM output, advanced and non-inductive design (with C5 speakers using the same type of technology), the focus of PWM can be a of frequency divider, compared with the traditional analog amplifier greatly reduced internal resistance, sound quality improved significantly. Colour:black Material:plastic Size:65 x 56mm Package Contents: 1 x Amplifier Board 3 x knobs(random colors, don't accept the specified color) 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.