Power Supply: AC DC 6-15V Op Chip: XR1075 Recommended voltage: AC DC 12V Working current: 5mA Tone Adjustment: Treble Bass of high resolution sound enhancement processor xr1075 For the listener, this is the reason that the "" technology can restore the true and beautiful sound of the scene Treasure. instructions 1. Connect the input end to 12V (AC or DC is OK), and connect the audio input end to the , The output end is connected with the rear power amplifier board, and the speaker is connected. (as shown in Figure 2 below) 2. The volume, treble output and bass output can be adjusted; from left to right: the first knob is high The second one is the bass adjustment, and the last one is the volume adjustment. Clockwise rotation increases, counter clockwise rotation decreases the volume and high and low sound effects. 3. Turn the red key to switch the sound effect with one key. Different batches may have slight differences in appearance, which not affect the use Colour:Red Material:ABS Package Contents: 1 x Audio 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.