CLAINS Class D amplifier with Bluetooth

Overview

This is an all-in-one audio amplifier board designed for a 2.1 channel system (two satellites + one subwoofer). It builds upon the popular TPA3116 amplifier and Bluetooth receiver by integrating a dedicated active tone control circuit, giving you much greater command over the sound signature compared to the basic bass/treble potentiometers found on simpler models.

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Detailed Component Breakdown

1. Class D Amplifier & TPA3116D2 IC

· Efficiency & Power: As before, this is a highly efficient (>90%) amplifier chip. Power output is typically around 50W x 2 (Stereo) + 100W (Subwoofer) with a 24V power supply, making it suitable for medium-sized rooms.
· Role: The TPA3116 acts as the final power stage, amplifying the prepared signal it receives from the tone control circuit.

2. 2.1 Channel Configuration with Crossover

· Dedicated Channels: Separate amplification for Left, Right, and Subwoofer.
· Built-in Crossover: A passive filter network separates the frequencies:
 · The Left and Right channels have high-pass filtering, sending mid and high frequencies to the satellite speakers.
 · The Subwoofer channel has a low-pass filter (often adjustable) that only allows bass frequencies to pass through.

3. Bluetooth Module

· Wireless Connectivity: Typically Bluetooth 5.0 for stable connection and low energy consumption.
· Codec: Commonly uses the SBC codec, suitable for most casual listening.

4. The Key Upgrade: Built-in Tone Control Circuit

This is the core differentiator. Instead of simple "Bass" and "Treble" knobs that only cut frequencies, a proper tone control circuit is an active EQ stage that happens before the main amplification.

What does "Active Tone Control" mean?
It uses operational amplifiers(op-amps) and other components to actively boost or cut specific frequency ranges, providing a more powerful and effective adjustment than a simple passive filter.

Typical Controls on such a board include:

· Bass Control: Adjusts the low frequencies (e.g., below 100-300 Hz). Turning it up will add punch and rumble.
· Treble Control: Adjusts the high frequencies (e.g., above 2.5-5 kHz). Turning it up increases clarity and sharpness of cymbals, vocals, and strings.
· Volume (Gain): The master volume control for the entire system.
· Subwoofer (Bass) Level / Crossover Frequency: This is a crucial dual-purpose control.
 · On many boards, this is a Level Control that adjusts the volume of the subwoofer channel independently.
 · On more advanced boards, this might be a Crossover Frequency knob, allowing you to set the precise point (e.g., 50Hz - 200Hz) where the sound transitions from the satellites to the subwoofer.

Key Features & Specifications (Enhanced)

· Power Supply: DC 12-24V. A 19V or 24V supply is recommended for full power.
· Inputs:
 · Bluetooth (Wireless)
 · AUX/RCA Inputs (Wired)
· Outputs:
 · Heavy-Duty Speaker Terminal Blocks for L, R, and Sub.
· Core Controls (The Tone Stack):
 · Master Volume
 · Bass Control
 · Treble Control
 · Subwoofer Level Control (and sometimes Crossover Frequency)
· Protections: Built-in (Over-current, Over-temperature, Short-circuit).

Advantages of the Tone Control Version

· Superior Sound Shaping: You are not limited to the board's default sound. You can boost the bass for electronic music, reduce treble to tame harsh speakers, or create a "smile" EQ curve (boosted bass and treble) for more exciting listening.
· Room & Speaker Correction: Allows you to compensate for poor speaker performance or the acoustic properties of your room.
· Flexibility with Source Material: Can enhance older recordings or music with weak production.
· A More Complete System: It eliminates the need for an external preamp or equalizer, providing a full, self-contained audio solution.