This is Preamp tune board,and with Treble,Midrang,Bass and, left-right channel balance and volume control; components are carefully , and the 4558 op amp with high cost performance can be used instead of the 5532, and the circuit board wiring is reasonable. Low noise, beautiful component layout, very suitable for enthusiasts DIY Name:Tone Board Working Power:AC double 12V-15V(transformer) 5-way: Treble,Midrange,Balance,Treble,Bass, Volume The production batches are different, the appearance is slightly different, but the function is the same Colour:Photo Color Material:plastic Size:about 20 x 6.5cm 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.