Contains 10 times the tone board preamp, and treble, alto, bass, volume control. With op amp IC package socket, flexible, easy to upgrade, suitable for different tastes. Board layout is reasonable, low noise, component layout nice, maximum to meet your critical eye. Components carefully areas, the use of cost-effective than high NE5532 op amp, high-quality small potentiometer, Black Edition BP Promise coupling capacitor, 1 % metal film resistors, capacitors, etc. Model: NE5532 Supply Voltage:Dual Power AC 12V - 18V Number of Channel: Dual-channel Audio Adjustment Types: 4 channels(treble+alto+bass+volume) Audio Input: sockets Audio Output: 3P terminal Input Voltage: 3P terminal PCB size(L*W):105 x 53mm Colour: picture color Material: ABS Package Contents: 1 * Preamp Preamplifier 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.