TDA2003 stereo amplifier with tone control 20 watts (10+10)

This amplifier is based on this project by construyasuvideorockola.

TDA2003 stereo amplifier

This is a stereo amplifier with two tda2003s..Each channel can put out up to 10 watts. It also comes with tone control operated by a JRC4558 op amp.

The four potentiometers control volume,low frequencies (bass), middle frequencies as well as high frequencies.

Schematic diagrams.

the tone control part

For original schematic and more info take a look at the pdf, page 8.

Volume control noise and other problems

You many have noise when turning the volume control potentiometer due to DC going through it (DC offset).

Τhere are a couple of measures you can take.

clean the pot by spraying it with oil (I used what I had-WD 40) and turn it vigorously
replace the pot with a better one
or modify the circuit slightly doing the following

I have found that this can be sold by adding one electrolytic capacitor-10uF- in my cases at the outputs of the 4558 preamp pins 1 and 7.If you add a small capacitor -say 1uF- bass may be cutoff lower.So more bass bigger cap.

All you have to do is replace the 1K resistor at pins 1 and 7 of the 4558 with a 10uF cap.

Here is the modified schematic.

An even more improved version of the circuit.

This is an improved arrangement of the circuit.Some capacitors have been added.The schematics above do not include these additions.