TPA3116d2 2.1 Amplifier with subwoofer + Bluetooth + SD Card + U-disk. Digital 2.1 amplifier board Introduction: Using a digital 2.1 amplifier board with two TPA3116 chips, the bass is powerful when listening to music with a subwoofer!

Following the previous generation desktop amplifier board, the amplifier has been upgraded with the addition of a low-frequency channel and all bugs from the previous version have been eliminated (possibly some undiscovered ones).

Characteristics: 

1. Relay controlled power supply, shortening the power circuit, reducing voltage drop, and the switch does not need to withstand high current, allowing for cheaper switch replacement without any impact.
2. Added NTC buffer resistor to prevent relay contacts from sticking due to a large current surge during activation, causing inability to turn off.
3. Using a digital amplifier specific common mode inductor, which takes up less space than a regular inductor and has sufficient current.
4. Replaced the audio input interface with a smaller volume, surface mount package, and also allows for channel switching (disconnecting Bluetooth audio signal after inserting an audio cable).
5. Full-function version without any restrictions, including AUX, Bluetooth, USB-DAC, USB flash drive, and TF card (USB flash drive and USB-DAC share the same data line and cannot be connected simultaneously). Please refer to the schematic diagram for detailed precautions! It is recommended to use a 16-20V 3A or higher power supply, and if using 24V, ensure good heat dissipation.

Schematic TPA3116d2 2.1 Amplifier subwoofer + Bluetooth + SD

PCB wiring diagram. There is a slight issue with the Bluetooth antenna packaging (DRC error), but it does not affect use, please ignore. This is a front view photo (no expensive toggle switches used).

The filter capacitor adopts a design of 5 parallel aluminum electrolytic capacitors, and the voltage withstand of the capacitor needs to be 25V or higher.

This is the back view of the actual product (in order to reduce the PCB area and be aesthetically pleasing, the Type-C and TF card slots are on the back, and the slots are shrunk inside to prevent accidental breakage). Remember to solder the 0R resistor on the back!

The limit voltage carries the Bluetooth idle current, and the standby heat sink is warm.

Heat sink PDD: Aluminum alloy electronic heat sink with back glue. Mainboard IC chip thermal conductive aluminum sheet.

The relay uses this model from Hongfa, which is small and flat, and 30V5A fully meets the power supply requirements of the amplifier.

The inductor 7W14A-100M High Power 10uH 16A Digital Power Amplifier Large Current Common Mode Inductor Filter.

Link to BUY 7W14A-100M inductor

The inductor patch 7G09B-100M 10UH 5A high current digital power amplifier dual-phase common mode inductor filter

Link to BUY 7G09B inductor

Decoding chip: JL Jie Li Bluetooth chip AC6955F stereo lossless sound quality Jie Li stereo chip

Below are the introductions of the functions:

1. Bluetooth function
2. USB-DAC function, connect via USB-C to Windows PC
3. TF card and USB flash drive playback