Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. Audio Preamplifier Stereo Preamp 20dB Gain Dual Op Amp NE5532 For Speaker Headphone 2X AU-10X NE5532 Audio Signal Preamplifier Headphone Pre AMP Board Gain... Power supply: DC9-19V Molieeigin Size: 87 x 50 x 37MMColour: Blackmaterial: plasticPackage Contents:1 x Audio Switch SwitcherOnly the above package content, other are not included. Feature supply: DC9-19V The amplifier chip is a op amp NE5532 This circuit can be used when the sound of your device is small when connected to the amplifier. It is suitable for small audio signal amplification, the amplification factor is 10 (20db), and the front 3.5mm interface can be connected to headphones; Input and output are 3.5mm... This circuit can be used when the sound of your device is small when connected to the power amplifier. DIY Audio Preamp AU-10X NE5532 Audio Preamplifier Headphone Pre Board Gain 20Db 3 20dB Gain Headphone Amp Input and output are 3., 5mm headphone or