"Impulse Response" for audio amplifier?

[clem_o]

Hi lumanauw,

IF (again IF) a single clipping signal will ruin all signals (even the small ones), then we have a problem.

Someone in the internet makes a "clipping indicator" with LED to know whether his amp (transistor feedback amp) clips or not. He found something interesting, that even in low level (not pushed hard), the transistor amp ALWAYS clips.

I'm not sure if it will happen or not, lets wait for others to comment?

Where is this 'clipping indicator'? Certainly the indicator on, say, the Adcom 565II doesn't blink until you push the amp hard...

Cheers!

Clem

 

[lumanauw]

Hi, Clem_O,

There's a clipping indicator thread here somewhere.

The article that I read, the clipping indicator is made by guys from audio magazine (I forgot the name of the magazine), and they write a short article about how a transistor audio amp (with quite big voltage rail) can clip easily.

 

[clem_o]

Hi lumanauw,

Thanks, I'll try to find that thread....

Cheers!

Clem

 

[anatech]

Hi Clem,
Adcom's clipping indicator senses when the diff pair is way out of balance. It's looking at the collector current of the transistor that does not drive the Vas. McIntosh has a circuit that senses excessive differential signals at the input (chip or transistors, called dynaguard). It's very well thought out too. Either one works very well.

-Chris

 

[clem_o]

Hi Chris, many thanks for the inputs!

Clem

 

[Gandalph]

Greetings from Norfolk

From my memory (sometimes somewhat shaky !! ) I seem to remember that a concet hall was 'tuned' for its audio response some years ago by firing a gun (possibly an artillery blank) and analysing the signals from a number of sensors ?

Richard

 

[clem_o]

Hi Gandalph,

I certainly would hope it was a blank!!

Not sure, but entirely possible. Must be a very big hall to require that much power - you can analyze hall energy decay characteristics by doing waterfall plots of the impulse - this shows not only the frequency response, but how the energy dies down over time. The decay period is particularly important to determine speech intelligibility as well as 'richness' of the music - unfortunately the 'optimal' values for the two do not match each other...

Cheers!