1. It Has Its Own Negative Voltage Conversion Circuit, Which Doubles The Power Supply Voltage And Has A Larger Dynamic Range And Is Less Prone To Distortion; 2. The Delay Time Uses A Voltage Controlled Oscillator And A Potentiometer To Adjust The Time. It Is Much More Advanced And More Convenient Than The Switch Type Recommended By The Pdf, Haha! That Exceed Those Of Others On The Market; 3. The Reverberation Part Refers To The Design Of Power Amplifier, Using Forward And Reverse Circuits To Stereo Reverberation.(If A Monophonic Power Amplifier Is Used, The Output End Can Only Be Connected To One Sound. If The Other One Is Left Empty, Must Not Be Connected In Parallel. This Will Cancel Out The Reverberation Signals, Resulting In Artificial Faults In The Music And Vocals Without Reverberation.) 4. The Stereo Music Amplification Part Has Treble And Bass Control, And The Two-Way Dynamic Microphone Amplification Circuit Has Volume Control And Treble And Bass Adjustment; 5. The Positive And Negative Poles Of The Power Supply Are Protected Against Reverse Connection, The Static Operating Current Is About 100ma, The Gain Of The Microphone Part Is 37db, The Music Part Is 20db, And The Treble And Bass Adjustment Range Is 12db. Description: 1. Circuit Board Size: About 17.8*5.5cm 2. Potentiometer Spacing: About 2cm 3. Category: Audio Accessories Note: Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Colour:As Shown Material:PCB Package Contents: 1x Tone Module 1 Set x Wires 1 Set x Button Mounting 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.