HI-FI Sound Amplifier for Home -200watts

A 200w HiFi mono amplifier with signal gain boosting options. This is TDA7294 class AB ic. Let's boost the power with TDA

Soldering equipments

Propanol (PCB cleaner)

Power supply

Transformer

Heatsink

Screws and nut-bolt

Speaker 4ohm 200watts

heatsink compound

Hello guys, today in this tutorial we will know, how to make a high bass amplifier circuit using Tda7294 Ic. And TDA series of Texas instruments is known for Hi-Fi performance. So, a very high power can be drawn from this amplifier circuit. This amplifier works on dual power supply that’s why we need a center tapped 24-0-24 volts 5 Ampere transformer to get better sound quality.

Today here, we will design only one channel (mono-channel) and using the same circuit it can be turned in stereo. But we are using Bridge method in mono channel which will provide 200watts RMS to single subwoofer. This is a class AB amplifier, so we need a good heat dissipator and a stable input power supply (High quality DC – using filter circuit).

Features:

1) High input voltage range (+-40v)

2) Muting/ standby function’

3) No switch on/off noise

4) Short circuit protection

5) Thermal shutdown

6) Low noise

In last we will make a fully working PCB and order it from our sponsor JLCPCB. JLCPCB is China’s Top PCB manufacturing company (just $2 for 5 Pcb).

1) TDA7294 ic

2) 1K resistor

3) 22k resistor

4) 10k resistor

5) 47uF 50-volt capacitor

6) 100uf 50volt capacitor

7) 1N4007 diodes

8) 1000uf capacitors

9) 47K potentiometer

10) 100nf polyster film capacitors

Circuit is same as given in the datasheet, after changing component placement the simplifier circuit diagram is shown below.

Both the TDA7294 Ic's are bridged together to provide a RMS power of 200watts. I also added the Gain potentiometer for loudness and powerful performance. Which will increase the strength of input signal or you can say pre-amplify the input. This circuit works on dual channel dual voltage. Check the power supply section from here.

Also, in bridge mode use 8ohm speaker for best output and use 24-0-24 power supply. Only the original version of this IC have, thermal, short circuit and overheat protection features.

I can design PCB at home, but single layer board with too many traces is not possible. The only reliable solution I can found is JLCPCB, prototype PCB service. They are offering 5pcs of double layered PCB just in $2. And If you sign-up using this link, you will get free coupons of worth $27 and other newcomer rewards.

I hand over my Gerber files to JLCPCB and got these amazing looking blue color PCB just in 7 days. Also, you can choose any color combination and surface finishing. Mine one is made with HASL and thickness of 1.2mm.

If you want to use the same design as mine then Download the Gerber files from here.

I unboxed the PCB and started with basic ones, resistors, diodes and capacitor. The I soldered both the audio ic and other small components as per list above.

Circuit is fully completed and we need a good big heat sink with this amplifier. You can also add active cooling methods like fans and all. Make sure to apply heatsink compound between the heatsink and IC. This will make good thermal contact.

If using the circuit in stereo or bridge mode as mine, add a layer of insulated mica sheet behind these IC’s. So that we can prevent aluminium heat sink to short circuit.

This is the short video about, how our 200W TDA7294 Mono amplifier is working. You can feel the bass and audio quality of this mono channel amplifier through this video.

The circuit can draw 200watts from the power supply, We need a good transformer which can provide dual channel power. I am using my toroidal transformer which can supply both 24v and 12volts @ 5amperes.

I made this filtered circuit to test my all big amplifiers. This is 10Ampere power supply which can be supplied up to 50volts. Get all the info about this filtered power station from here.

For now, we are just working on a single 200w channel but in future we will also make dual channel, one channel for speaker and other for woofer. We will make a separate PCB for that and order it from JLCPCB.