The amplifier dynamics is approximately 100 times, the capacitor is around 22 times, and the music section is about 5 times. The mixed output can drive headphones. Note that the input voltage multiplied by the amplification factor must not exceed the supply voltage. Select an appropriate power supply voltage. Higher voltage results in a larger signal and helps prevent signal clipping. If the input signal is small, the amplifier can operate effectively at a lower voltage. Use a high-quality power supply with low ripple, as poor power quality may cause audible hum. Power interface is DC 5.5 x 2.1 mm, center positive, outer negative. Power supply not included. Color: black Material: plastic Package Contents: 1 x MA-2S Audio Preamplifier The package includes only the items listed above; other items are not included. Note: Lighting conditions and display settings may cause slight variations in the color of the item as seen in images. Measurement error allowance is +/- 1-3 cm.