LM386 softer clipping

[Vivek]

Rob Strand had posted a clipper/ limiter system with diodes referenced to power supply.



This can be used to soften the output of a rail saturated LM386 (Or any other Rail saturated Opamp circuit), by adding one more knee close to each rail. For LM386, I suppose we will have to use inverting pin, Opamp style feedback as I had posted earlier.

I feel this might be an excellent idea for this purpose.

[Steben]

Rob Strand had posted a clipper/ limiter system with diodes referenced to power supply.



This can be used to soften the output of a rail saturated LM386 (Or any other Rail saturated Opamp circuit), by adding one more knee close to each rail. For LM386, I suppose we will have to use inverting pin, Opamp style feedback as I had posted earlier.

I feel this might be an excellent idea for this purpose.

Yes. And follows power sag.

[Vivek]

YES !!!!

Follows power sag !!!

I remember your idea to put a resistor in series with power supply going to Opamp, to get power sag in the traditional way

+ your comment that LM386 has variable current draw (especially if the load impedance is low)

[Clint Eastwood]

Here is my attempt:



And here the waveform it creates:




The waveform clips asymmetrically, because the spice simulation has the output dc voltage not halfway the supply, but at 5.2 volts.
you can get softer clipping by lowering the led voltage drop,  using pairs of one green and one red led, or two red leds.

[PRR]

....the spice simulation has the output dc voltage not halfway the supply, but at 5.2 volts.

If you look at the internal circuit, that is probably correct. Asymmetric clipping hardly affects the perceived loudness of a pocket radio.

Has anybody tried running on 3V supply with <4 Ohm load? Marginally beyond spec? Not as a loudspeaker driver but as an in-line flavor box? The natural curvatures are in the few-tenths-Volt range, so may stand out more at few-volt than with 9V or 12V supply.