High-fidelity portable Bluetooth headphone amplifier (PCM1794A+TPA6120 solution)

Let’s start
with the design reference of this project (the project of the two big guys below, which was modified and finally designed with a smaller high-fidelity portable headphone amplifier):
High-fidelity portable Bluetooth headphone amplifier (PCM1794A+TPA6120 solution) - Jialichuang EDA open source hardware platform (oshwhub.com)
QCC303X Bluetooth receiver - Jialichuang EDA open source hardware platform (oshwhub.com)
 
1. Project introduction
This project is a portable high-fidelity Bluetooth headphone amplifier based on tpa6120 headphone amplifier and pcm1794a audio dac, using qcc3034 Bluetooth soc. Supports sbc, aac, aptx, aptxhd, aptxll encoding formats.
It can be slightly modified to support USB sound card mode (44.1khz, 16bit), driver-free, and supports up to 16bit/48k. You need to replace the typ-c interface and connect it to tpa6120. Please refer to the manual for details.
 
2. Function introduction
1. Bluetooth playback
2. Press the button to switch songs
3. Press the button to adjust the volume
4. You can select the internal filter mode through jumpers, fast roll-off and slow roll-off
5. Optional pre-emphasis filter, jumper control
6 .Charging indication, charging current 1A
7. Specially designed power supply and ground grid to minimize noise and crosstalk
8. The maximum output amplitude is 2.24VRMS, which can drive most mid-sole high-impedance and low-sensitivity headphones.
9. The output impedance
 
is 10ohm. Other instructions:
1. In order to reduce THD, it is best to use NPO/C0G material for the IV feedback capacitor
. 2. The USB sound card function can be added by replacing the TPYEC female socket (requires DP, DN, VCHG, GND, Please refer to the Bluetooth module data manual for details) 3. The block diagram of the Bluetooth module using the finished AL3034 module Bluetooth receiver of
a certain product is as follows: Project sketch: