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A different approach to the TDA2050 suggested schematic in the datasheet. One of the differences is the negative feedback. Usually the feedback is DC decoupled via a large capacitor, but I don't like this technique. Here's why. The capacitor and resistor form a high pass filter, and at lower frequencies in the bass range the output starts to roll off. Typically you'd say whatever, but remember a negative feedback can become a positive feedback very easily, it's all about the phase angle. That's exactly what starts shifting at roll off. You might have noticed when you've built such power amps that sometimes it starts oscillating at a low frequency, right after a long bass kicks in. These oscillations are very undesirable, because they stress the op amp and if left to continue, would eventually destroy it. Moreover my opinion is that they increase the THD somewhat. The second advantage is the ripple rejection is somewhat increased. I'd usually suggest to use a bridged amplifier with 2xTDA2050 to negate the need for the output capacitor, but that's optional. Also to ensure the amp doesn't go into high frequency oscillations I added a frequency dependant negative feedback via the 100pF/100ohm feedback. I usually recommend this strongly in conjunction with the zobel network and perhaps an input high frequency filtering, especially when you use a passively mixed stereo input signal.
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