Best Audio Clipping Ind Circuit

[Paul kent]

I am driving a 12W audio amp module from a PC soundcard and would like
to fit an _adjustable_ clipping indicator.

Would like to keep the circuit as simple as possible. Not a hi-fi
application. It's just because the PA speaker is in another room and I
cannot hear if distortion occurs.

What are the pro's and cons of the circuits below? Any other
suggestions?

http://electroschematics.com/5942/audio-clipping-indicator/

http://electroschematics.com/302/peak-indicator-circuit-schematic-tlc272/

The next is simple, but not adjustable, and would need to be modified
for a 12VDC supply.

http://electroschematics.com/5942/audio-clipping-indicator/
(fourth diagram down)

Thnak you for any advice.

Paul Kent

 

[Paul kent]

Use a compressor instead, like...

http://tinyurl.com/4npqpcl

Nice, but I want a small circuit I can build into a device. Sorry, if
that wasn't clear.

Paul Kent

 

[Kevin McMurtrie]

I am driving a 12W audio amp module from a PC soundcard and would like
to fit an _adjustable_ clipping indicator.

Would like to keep the circuit as simple as possible. Not a hi-fi
application. It's just because the PA speaker is in another room and I
cannot hear if distortion occurs.

What are the pro's and cons of the circuits below? Any other
suggestions?

http://electroschematics.com/5942/audio-clipping-indicator/

This isn't too bad, but it will vary in sensitivity with the battery
voltage. A low power regulator driving R2 and R4 will fix that.

http://electroschematics.com/302/peak-indicator-circuit-schematic-tlc272/

There's a very long list of things wrong with that one.

The next is simple, but not adjustable, and would need to be modified
for a 12VDC supply.

http://electroschematics.com/5942/audio-clipping-indicator/
(fourth diagram down)

Same link.

Thnak you for any advice.

Paul Kent

Since this isn't hi-fi, feed the speaker output to a 47 Ohm resistor,
then to a bridged rectifier, then to a string of cheap LEDs. The more
LEDs in series, the higher the illumination threshold. It will probably
be around 8 red, 6 green, or 4 blue/white. 12W RMS into 8 Ohms is the
typical quoted output of a bridged amplifier running on 14.4V.

 

[Paul kent]

Same link.

Sorry, it should have been this:

http://www.siliconchip.com.au/cms/A_30810/article.html

Fourth circuit down on the page.

Any further comments?

Paul Kent

 

[Kevin McMurtrie]

Sorry, it should have been this:

http://www.siliconchip.com.au/cms/A_30810/article.html

Fourth circuit down on the page.

Any further comments?

Paul Kent

Not bad. A 4.7V zener diode may be wrong for a 12W amp. An adjustable
voltage divider may be better.

 

[Ralph Barone]

I am driving a 12W audio amp module from a PC soundcard and would like
to fit an _adjustable_ clipping indicator.

Would like to keep the circuit as simple as possible. Not a hi-fi
application. It's just because the PA speaker is in another room and I
cannot hear if distortion occurs.

I had long forgotten a circuit I did decades ago to do exactly this. I've
just written it up and added it to 4QD TEC:

http://www.4qdtec.com/Audio/SPPPI.html Speaker powered Peak Program
Indicator

Enjoy![/QUOTE]

Do you get a long enough optical pulse out of the LED to "see" the
clipping, or should you throw a small capacitor somewhere in the circuit?