Table of Contents
TDA7297 – Power amplifier circuit add tone control, simple schematic using the integrated circuit TDA7297 or equivalent TDA7297SA, TDA7266 for audio amplifier. Add passive tone control and volume adjustment. Include PDF, PNG and Gerber PCB
About the circuit with TDA7297
Basic application of the integrated circuit as seen in the datasheet for an amplifier up to 15 + 15 Watts stereo and add tone control. In the diagram, the circuit formed by R10 / C15 and R11 / C16, form a low pass RC filter to about 482 KHz. If you prefer you can change this filter to your liking.
For tone control we have a James Tone Stack circuit, as our components are passive, the adjustment will always be up to 0DB. This signal level will also depend on the impedance of the signal source. If you prefer you can also change this circuit as you wish. You can even use the free Download software Tone Stack calculator software to make calculations easier and simulate the best to your need. If you want you can also see the calculations here on this site. The setting will be for bass and treble. In some cases, depending on the signal level, a preamplifier may be needed, in most applications it is not necessary.
Capacitors C11 and C12 couple the audio signal to the TDA7297 in addition to blocking any DC current. As the input impedance of the TDA7297 is about 30K, we have an RC high-pass filter circuit cut at about 5Hz, using 1uF capacitors. Sufficient for most applications.
R7, R8 and C9 form the TDA7297 mute and stand-by circuit, using C9 with a value of 100uF, we have a sufficient time constant to avoid the pop when turning on the amplifier.
In our diagram, to power the amplifier will use a 9 to 14 VAC transformer, if using DC source, use jumpers to make the connections in place of the rectifier bridge. We used a large 4.700uF capacitor, which is enough, but if you prefer you can use a 6.800uF capacitor, 2 100nF capacitors were added next to each amplifier’s power pin, for decoupling. For rectification we use a rectifier bridge to make better use of the space.
The board is very compact, in the PCB tracks on the component part (in red), you should use jumpers (piece of wire or component terminal) and thus use single face board. I also added the Gerber file if you prefer to order your board from a PCB manufacturer.
As an equivalent, you can use the TDA7297SA for 10 + 10W and the TDa7266 for 7 + 7W
You must use a heat sink in the CI, if you prefer you can use insulator between the chip and the heat sink, the metal housing is connected to the GND. Isolating will avoid any risk of short circuit.
Diagram Schematic of the amplifier with TDa7297
PCB – printed circuit board suggestion
Parts list to assemble the amplifier
| Part | Value | Description | Amount |
| Capacitors | |||
| C1, C2, C3, C4, C6, C8 | 22n (223) | Polyester film capacitor | 6 |
| C5, C7 | 2,2n (222) | Polyester film capacitor | 2 |
| C9 | 100µF/25V | Electrolytic capacitor | 1 |
| C10, C11 | 1µF (105) | Polyester film capacitor | 2 |
| C12, C14 | 100nF (104) | Ceramic capacitor | 2 |
| C13 | 4.700µF/25V | Electrolytic capacitor | 1 |
| C15, C16 | 220p (221) | Ceramic capacitor | 2 |
| Semiconductors | |||
| B1 | KBL608 or equivalent* | Rectifier bridge | 1 |
| IC1 | TDA7297 | Stereo bridge amplifier integrated circuit | 1 |
| LED1 | Led 5mm | Led color to choose | 1 |
| Several | |||
| J1 | JST-XH-03 – 2.54mm connector 3 pins | Audio input | 1 |
| J3 | Terminal Block 2 pin | Power – Connect transformer | 1 |
| J4 | Terminal Block 2 pin | Right channel audio output | 1 |
| J5 | Terminal Block 2 pin | Left channel audio output | 1 |
| Resistors 1/4W | |||
| R1, R3, R9 | 6k8 | Blue, Gray, Red, Gold | 2 |
| R2, R4, R5, R6, R10, R11 | 1k5 | Brown, Green, Red, Gold | 6 |
| R7, R8 | 47K | Yellow, Violet, Red, Gold | 2 |
| R12, R13 | 1M (Not used) | Brown, Black, Green, Gold | 2 |
| Solder, Wires, Pci, Box, Transformer etc. | |||
* Some equivalent bridge rectifiers
GBU4J, GBP410, KBJ610G, GBU606, GBU808, GBU406, GBU608
Download files for this project, includes Gerber, PNG and PDF files
See our other project using this same CI – Stereo Power audio amplifier with TDA7297 – 2 x 15 Watts
Hi, awesome project, thanks !
But I have some questions…
Can I use a 18-volt DC power supply, and if yes, how can I hook it up to the amp because there are 3 pins? What does rem +b mean? And how is the sound quality of the amp? Is it noisy?
Hello R2
Hello, you can connect to the AC AC connector, no matter the polarity. However, you can also remove the rectifier bridge and make a jumper between the AC /+ and AC/- pins. If you don’t understand, I can give you an illustration.
Hy .Many thanks for this project but I’m a noob in electronics and i want to ask you for dc power if can you be more specific in what to do exactly? I just remove the rectifier and that it ?
Hi Adam,
You can connect a 12 or 18V DC source in the power connector, do not worry about polarity.
R12, R13 1M will it be used? will not be used?
Hello , nice Project. Where can i buy PCB and Parts. or only PCB?? :-))
Nice Greetings from Germany .
Sorry , i can´t fast answer. we make vacation for 14 day.
VG Ulf
Hello Ulf Schlieder
Buy PCB in JLCPCB
The gerber files:
https://www.dropbox.com/s/4yfvhye3f676dal/TDA7297-xtronic.zip?dl=1
How to Order PCB:
https://www.te1.com.br/2021/03/jlcpcb-brasil-como-comprar-pcb-gerber/