Contains 10 times the preamp tone board, and the treble, alto, bass, volume control. With op amp IC socket package, flexible, easy to upgrade, suitable for all tastes. Board layout is reasonable, low noise, beautiful, maximum component layout to satisfy your critical eye. Carefully component areas, the use of cost-effective than high NE5532 op amp, high-quality small potentiometer, Black Edition BP Promise coupling capacitor, 1percent metal film resistors, capacitors, etc. Model: NE5532 Power supply voltage: Double power supply AC 12V - 18V Channel Number: Dual-Channel Audio Types of adjustment: 4 channels (treble and high and low and volume) Audio Input: sockets Audio output: 3P terminal Input voltage: 3P terminal Colour: blue Material: PCandmetal Package Contents: 1 x NE5532 OP-AMP HIFI Amplifier Preamplifier finished Board 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.