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Low Cost 2x20 Watt Stereo Amplifier by TDA2005

Project Summary

This circuit is a small stereo amplifier for all suitable applications like amplifying small speakers, boxing, etc. It is also suitable for car use but before, the power supply must be choked with at least 150mH and it must give up to approximately 6 to 7 amps during the upstream performance.

Project Description


Figure 1 

Technical data:

Performance of TDA2005M: (for this circuit); At 14.4 V supply voltage: 2 × 20 watts (stereo) into 4 Ohms.
Distortion: Approx. 0.2% at 4 Watts into 4 ohm load.
Frequency Range: Approx. 20 Hz to 22 KHz.
Input Sensitivity: Approx. maximum 150 mV rms. .
Power supply: + 8 to 18 volts, approx. maximum 3.5 Amps per channel.

Appropriate heatsink for the amplifier is SK08 with a height of 50 mm (approx. 2.5 K per watt). You should drill the cooler after soldering the board to center it properly. The TDA2005 also needs not be isolated from the heat sink, since the metal mounting part of the IC is grounded. You should use thermal paste to improve the heat dissipation. After the assembly , case construction is left to the builder. 100K potentiometers are used for adjusting the input volume. The potentiometers are absent in the layout. The 100K resistors need only be installed if the 100 K potentiometers are not used as shown in the layout.

You should use a well designed quality transformer to get less noise. It will be another good way to use a sufficient battery to power the circuit. Keep the supply wires as short as possible. Input source should be isolated from the external noises too. It is recommended to use coaxial cable to connect the input audio.

Project Files

File NameFile Size
Schematic, PCB and Layout files524.61 KB
Tags: stereo, amplifier, 20 watt,

Comments on this Project:

By alp 0Score: 

7 years ago:  thank you my frend

By berting labra 0Score: 

5 years ago:  I like it when it comes in very handy without the use of external power supply or adapter...

By Martin 0Score: 

5 years ago:  the circuit its ok??... because in my pcb of this desing the output power is very low.. the power supply is 16v aprox... thank

By mario west 0Score: 

5 years ago:  wow! this is very handy! i will make a good enclosure box for this for proper protection!

By dinh 0Score: 

5 years ago:  thank you

By Dwayne K 0Score: 

5 years ago:  this was one of the first things I built back in the 90's,,,I desoldered the part from a older car POWER BOOSTER/EQ To be honest it actually rocked far beyond my expectations as a guitar amplifier!

By moy 0Score: 

5 years ago:  muchas gracias, muy buenos circuitos ok
saludos desde Latinoameria

By mig 0Score: 

5 years ago:  Can I power this circuit from ATX (power supply for personal computer)??? Thanks!

By maz 0Score: 

5 years ago:  I built this circuit and it works OK. I replace original condenser 270nF with 330nF.

By hrvat 0Score: 

5 years ago:  It's possible to power this circuit with PC supply, between black and white wire. And for turn supply on, you have to short-connect black and green wire.

If we look at some others schematic and their prices, this is very good amplifier for little price.

Author, thank you!

By roger datugan of orlando florida 0Score: 

5 years ago:  your circuit is very nice and simple.thanks for your pcb layout and components layout. i tried and built this amplifier with different layout.this amp sounds good ang powerful,its a BTL amp..

By amp 0Score: 

4 years ago:  HEIGHT: 70mm
WIDHT: 85mm
DEPHT: 35mm

I have this heatsink, is it OK for this amplifier for about 2 hours on middle power?


By amp 0Score: 

4 years ago:  I built amplifier, and it works OK! DC offset on one canal is 10mV, and on another is 75mV. :)

By Angel Ramses 0Score: 

4 years ago:  That PCB looks so wonderful congratulations to the chef!!!

By Konstantin Mac. 0Score: 

4 years ago:  A perfect TDA 2005 20 W Amp. Congratulations to all of You.

By fulber 0Score: 

4 years ago:  what would be a good power supply for this? It says 3.5 amps per channel, so 7 in total. But psu with this power are very expensive.

By Dario 0Score: 

3 years ago:  Would it be ok if i use a 50k pot instead of a 100k?

By matias 0Score: 

3 years ago:  hello, with a 12v transformer and 3A it works?

Gustavs Strautnieks

2 years ago:  Why do you need two IC's, if they're stereo?

David Bradley
By David Bradley (0) 0Score: 

2 years ago:  Hi Gustavs, The TDA2005 has 2 versions: the M series (TDA2005M)(used here) is a mono channel 20 watt device, the S series(TDA2005S)is a stereo 10 watt per channel device. The author is using a pair of mono's to create a 20 watt stereo amp. Hope this helps.

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