Introduction: 2XTDA7294 150W
L = 8Ω ; VS = ±40V
L = 6Ω ; VS = ±34V
L = 4Ω ; VS = ±30V
(TESTED WITH 50V AND WORK FINE)
This amplifier can work from any stable power supply (without bipolar power supply)
Step 1: PCB
How to made pcb can find in my other instructables www.instructables.com/id/Tda7560-4X50w/
This PCB i choice because this is smaller (8.8cmx4.5cm)
Step 2: PCB
2x 2200uF 50v (Capacitor can be at 25V)
1x 10k ohm
1x 30k ohm
1x 47k ohm
2x 680 ohm
7x 22k ohm
More about blue potentiometer find in next step.
Step 3: AMP
This amplifer can be used 1x120W(8ohm) or 2x75W(8ohm).
Amplifier can buy form china(ebay, aliexpress,...)
With one chip 4-6$
With two chip 8-15$
DC/DC Boost Converter:
150W DC-DC Boost Converter ±3$
200W DC DC Boost Converter ±5$
250W 10A DC-DC boost converter (VERY BAD SOUND QUALITY)
Step 4: Power Supply
This power supply i buy and test on this amplifier.
Capacitor for sound quality, ferrite ring for max power(W) from boost converter.
Output power ±100W (need change: output capacitor to ±4400uF, potentiometer 12-20kohm for made 40v, bigger ferrite ring with 7 turns)
).(100watt after upgrade)STANDARDDIODE SCHOTTKY MAX VOLTAGE 45V.
Output power ±130W (need change: output capacitor to ±4400uF, bigger ferrite ring with 15 turns).
DC-DC boost converter with current adjustable audio quality is very bad (with converter 600W, i can get about 50W to amplifier (25V-0-25V))
Step 5: Blue Potentiometer, Made "bipolar Power Supply"
This potentiometer (can be used resistor) made virtual gnd for dc-dc boost converter.
If Power supply 40v resistor must be 4k-5k ohm, if 32v 3.2k-4.2k ohm resistor or potentiometer.
To find best resistance need check voltage with multimeter (GND and - or +) check need do on loaded amplifier.
Why dc dc boost converter, if you use my made way, power supply must be stability to get smooth voltage in GND.
If power supply will be not stability, this can broken battery (20 18650 battery is rip :(
With transformator i don't test (if this work this resistor not need)
Step 6: Input Signal Boost
Android phone use very small sound volume to AUX and Bluetooth.
There apk for boost 100% amplifier power:
For android 4.4 and higher:
For android at 2.0 to 4.3:
Without this program on Samsung Galaxy S3 output power is ±12.5W , with program max ±149.6W(phone out quality with distortion)
This app can not work, make quieter (tested and work on android 6.0.1)
5 years ago
Tested with 150W dc-dc boost converter (changed: diode schottky MBR20100CT(20A, 100V), output capacitor 50V3200uF, input capacitor 2200uF)
Dc-dc boost converter output:
Test 1. 50Vx3.46A =173W to speaker 121W
Test 2. 55Vx3.4A =187W to speaker 131W
Amplifier efficiency 70%.(max)