New here, noob about electronics. I am in a bit of concern, I caused the minus and plus to touch on the source that powers my amplifier with two channels (TDA2040 transistors). After that short, one of the channels sounds less loud than the other. Though in the specs is mentioned that these transistors have a built in short circuit protection. Could it be damaged? And if I may need to change one of them, could I better change them both with TDA2050, on the same board without changing other components there? And a third question, I'm trying to make sure if I did well putting a diode on the 'minus' coming from the power source to the amp so the current to flow from the minus away, but not towards the amp. It is a voltage marge to affect that diode, at a 18V power supply? Did it impede the proper tension to fill into the whole circuit beyond the diode's limitation (I don't know exactly how a diode function, I know that a LED has a voltage limitation that's why I presume any diode must have one)? Thanks a lot for any suggestions/explanations. Good day.

Does anybody know what is the difference between TDA2040, and TDA2040A? Thanks.

  • \$\begingroup\$ All semiconductors have an I*t thermal limit when exceeding the steady current limit, just like a fuse. \$\endgroup\$ Commented Nov 14, 2016 at 5:18
  • 4
    \$\begingroup\$ The TDA2040 is NOT a transistor. It is an integrated circuit. It is a complete audio amplifier in a single package. \$\endgroup\$
    – JRE
    Commented Nov 14, 2016 at 6:48

1 Answer 1


(1) Could it be damaged?

Yes. The fact that one channel is now much quieter than it was before would indicate that damage has been done somewhere in the circuit, though not necessarily in the IC.

(2) could I better change them both with TDA2050?

(3) putting a diode in the supply feed

enter image description here

Swapping for a different amplifier is up to you. Comparing the tda2040 and 2050 circuits they are pin compatible but you may need to change a couple of RC values.

Adding diodes into the supply feeds would introduce a voltage drop. Depending upon current this would be in the range 1-2V for each diode.

  • \$\begingroup\$ I think I will take off the diode indeed. Meantime, some research convinced me that between the two TDA2040 and TDA2050, the former is being seen as sounding better, warmer, and is more efficient as consumption versus amplifying power, than the latter. So I went to an Electronics shop and bought two brand new TDA2040. But I'm not yet sure if to replace them, because they might not be damaged. As I wrote in the response post beneath, it might be something with the speaker if it still sounds lower even though I changed the channel that feeds it with the one of the initial 'good' speaker. \$\endgroup\$
    – Weebx
    Commented Nov 15, 2016 at 2:55
  • \$\begingroup\$ @OnniaOx: This information belongs in the question. You can edit the question yourself and put all the information in this comment into the answer. \$\endgroup\$
    – JRE
    Commented Nov 15, 2016 at 10:39
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    \$\begingroup\$ Shorting the power into the amplifier could cause a POP that could damage a speaker. \$\endgroup\$
    – JRE
    Commented Nov 15, 2016 at 10:39
  • \$\begingroup\$ Sorry for posting not properly. I'm kind of lost now. I understand I have to start another topic, for the question regarding the difference between two IC's above... I tried to delete this one but says it's impossible because it has answers. \$\endgroup\$
    – Weebx
    Commented Nov 15, 2016 at 13:05

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