TPA3126D2 power amplifier + AUX + Bluetooth

TPA3126D2 power amplifier + AUX + Bluetooth box

TPA3126D2 50 + 50-W with Bluetooth + case 3D, stereo, low-idle-current Class-D power amplifier circuit, TDA3126 power amplifier IC, 2 auxiliary input, 1 Bluetooth input + 1 AUX output

Tpa3126D2 Power Amplifier + Aux + Bluetooth Box
Tpa3126D2 Power Amplifier + Aux + Bluetooth

Project Overview: It has reverse input function. There are two AUX input channels (one front and one rear) and one Bluetooth input channel. The overall volume and each channel volume can be adjusted. There is an AUX output interface (on the side), and when used with the amplifier, the output circuit will be reduced.

There is another way to use an AUX cable, one end connected to the AUX output and the other end connected to the AUX input, which can provide certain gain to the amplifier, and it has been tested to be effective. The original file of the casing can be exported in the PCB file, and the attachment is the modified file with some silk printing added. Other precautions and instructions are also described in the schematic diagram.

Get new posts by email:

Precautions: The amplifier is a stereo with left and right channels. It is recommended to use two 4Ω50W speakers (as stated in the manual). The amplifier output interface should correspond to the speaker interface.

NL connects to the negative pole of the left channel speaker, PL connects to the positive pole of the left channel speaker, NR connects to the negative pole of the right channel speaker, and PR connects to the positive pole of the right channel speaker.

Currently, a 50K inverter is used, but it is recommended to buy a 10K one, as there may be current attenuation with the 50K inverter, or the amplification factor of the operational amplifier may not be sufficient. You can refer to the calculation formula in the schematic diagram and change the resistance to amplify the current. The demonstration video was not able to find a ready-made 50W speaker at that time, only a 4 Ω 20W one was found, so the audio quality and volume of the test were not good.

Schematic TPA3126D2 power amplifier + AUX + Bluetooth

Schematic Tpa3126D2 Power Amplifier + Aux + Bluetooth

About ic TPA3126

The TPA3126 is an integrated circuit (IC) that is widely used for audio amplification purposes. It is specifically designed for high-performance audio systems, offering excellent audio quality and high efficiency. The TPA3126 operates on a wide supply voltage range, making it versatile and suitable for various applications. This IC provides a powerful output, making it ideal for audio devices such as home theater systems, soundbars, and portable speakers. Additionally, the TPA3126 features built-in protection circuits to ensure the safety of the amplifier and connected speakers. Its compact size and low heat dissipation make it a popular choice among audio enthusiasts and professionals alike. Overall, the TPA3126 IC offers an efficient, reliable, and high-quality solution for audio amplification needs.

About MH-M18 Bluetooth module

Mh-M18 Bluetooth 4.2 Nodule
Mh-M18 Bluetooth 4.2 Module

The MH-M18 Bluetooth module is a compact and versatile wireless communication solution. It utilizes the Bluetooth 4.2 technology, allowing for seamless and reliable connections with other Bluetooth-enabled devices. This module offers a range of up to 10 meters, making it suitable for a variety of applications. Its small size and low power consumption make it ideal for integration into portable devices or IoT projects. The MH-M18 module also features a built-in microphone and speaker, enabling easy audio communication. With its simple interface and easy-to-use AT commands, this Bluetooth module provides a convenient and efficient solution for wireless connectivity needs.

BOM Mini D class power amplifier with preamplifier

R1, R2, R3, R4, R1210k (103)0603 SMD resistor5
R5, R6100K (104)0603 SMD resistor2
R720K (203)0603 SMD resistor1
R8, R9, R10, R113.3 Ω (3r3)0603 SMD resistor4
RN1,RN2,RN3,RN4,RN5,RN6,RN7,RN8,RN9,RN1010 kΩ (103)10 kΩ 0603×4 Resistor Network10
U1,U2,U10,U12RV097NSB50KPotentiometer 50k4
C1,C2220uF/35VSMD electrolytic capacitor2
C4220uF/16VSMD electrolytic capacitor1
C5,C6,C73.3uF0603 SMD ceramic capacitor3
C12, C13, C14, C15, C161uF0603 SMD ceramic capacitor5
C17, C18, C19, C20220nF0603 SMD ceramic capacitor4
C21, C24, C27, C30680nF0603 SMD ceramic capacitor4
C8, C23, C26, C29, C3210nF0603 SMD ceramic capacitor6
C9, C33100nF0603 SMD ceramic capacitor2
C10, C22, C25, C28, C31, C341n0603 SMD ceramic capacitor6
LED1,LED2Red LED 0603Red LED 06032
Q1NCE3090K30V 90A 5.8 mΩ@10V,20A 105W 2.5V@250uA N Channel TO-252-2(DPAK) MOSFETs1
U3TPA3126D2DADHTSSOP-32 — 50-W Stereo, Analog-Input, Class-D Audio Amplifier with Low, 15-mA Idle Current and AM Avoidance1
U4,U5LM324DTSOIC-14 — Quad 1.3MHz Operational Amplifier2
U6LM2596S-5.0/TRTO-263-5 — DC-DC Converters 5V1
U9MH-M18MH-M18 Bluetooth module1
U11SGM3204YN6G/TR-5.5V~-1.4V 200mA 1.4V~5.5V SOT-23-6 DC-DC Converters1
CN2,CN3,CN4XH2.54-2PIN-Connector 2 pin 2.54 mm3
D1SS34SMA — Schottky diode1
DC1DC-042C-W-2.0DC Power Receptacle 6.3 mm1
J1,J2,J3PJ-307C3.5 mm headphone jack3
L133uH (330)3A 33uH SMD Power Inductors 12×12 mm1
L2,L3,L4,L510uH (100)6.5A 10uH Shielded Power Inductors 11.6×10 mm4
U8BFS1206 32V 5A1206 SMD fuse1
U14,U15KF301-5.0-2P5 mm 1.5 1 2 Plugin, P=5mm Screw terminal2

Download files, links, and notes

Tpa3126D2 Power Amplifier + Aux + Bluetooth Box
Pcb 3D

Download PCB in Gerber, PDF + Case 3D




How useful was this post?

Click on a star to rate it!

Average rating / 5. Vote count:

No votes so far! Be the first to rate this post.

As you found this post useful...

Share on the social networks!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Photo of author
About the author blog author. Electronics technician for the technical school of Brasilia - Brazil. Interested in electronics, circuits and technology in general.

Leave a Comment