Karaoke Preamplifier Board Microphone Amplification and Reverb Effect Board Volume Control Pre-Amplifier Board Module Supports computer software settings; once debugged, can be downloaded and saved to the chip. Various sound effects: hall/room, delay, pitch shift, voice changer, metal, electronic, wah, chorus, etc. Various EQ parameters, bass boost, 3D stereo widener, harmonic exciter, bandpass filter, low-pass/high-pass filter, notch filter, etc. Gain adjustment, noise reduction, AGC, compression, anti-feedback, frequency shift, vocal cancellation, etc. Built-in wide-voltage DC/DC buck-boost circuit; Reverse polarity protection; Silent power-on/off circuit, virtually no popping sound during power-on and power-off; Operating voltage: DC9V-40V; Power consumption: 1.6W; USB interface: Type-C NOTE: Software download, please contact customer service. Color: Green Material: PCB Package Contents: 1 * Preamplifier Board 1 set of accessories 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.