Frequency selective feedback:

[NEWBIE_000]

M new to this forum guyz. Plz help me in this cirrcuit that how actually this circuit(untitled.gif) works as a frequency selector. This circuit is my feedback for OP-AMP 5532 from output. Is it really a frequency selector feedback circuit?? Plz clear my doubts. Thanks in Advance.

 

[Nigel Goodwin]

All the parts between C6 and P2 are the feedback, and it's frequency selective.

However, that's an absolutely crap and low quality circuit.

 

[NEWBIE_000]

Hello, i appreciate ur reply and i knw tht this is crap for almost evry1 out here. But m jst a startr in the field and nd some extra help from u experts. Could u giv a bit detailed explanation of how this circuit works as a frequwncy selective ciruit.
THANK U VERY MUCH

 

[Nigel Goodwin]

It's too much bother to work out what the feedback is doing, particularly as there's no component values.

Presumably it's some kind of tone control?.

Why are you interested in the circuit anyway, as I said it's really naff - I wouldn't recommend building it.

 

[RCinFLA]

The amp has some biasing issues but the principle of the feedback is a variant of a twin-T notch filter. As the feedback goes through the attenuation notch of the network, the gain of the amp will increase due to reduction in amount of negative feed.

Because of the phase shifts in the feedback path you may to reduce the gain of amp's forward circuit to prevent oscillation.

 

[NEWBIE_000]

I also thought it would be twin t. hmm......
Thanku R CinFLA, Goodwin. Plz continue ur reviews.

AND PRAY FOR JAPAN. BAD tIM FOR THEM