VI limiters

[sakis]

it is been very well known that classic VI limiters as exist in some amplifiers are sonic killers ....

some sugested that in some circuits the removal of the limiters will be an upgrade to the amplifier sound ( i dont recall someone saying anything about the safety margin altered but thats ok )

ok ...the question :
1---anybody has any idea how to design a VI limmiter that will not have any effect in the sound ???

2--- anybody has any idea about something i read once about VI limmiters created with optocouplers that have no effect in sound quality ????

all opinions are welcome
thanks

[richie00boy]

You need to read Mikek's Electronics World article.

[teemuk]

United States Patent 7,061,740, System and method for protecting an audio amplifier output stage, Eric Mendenhall

(Hint: Google patents)

...and

http://www.aes.org/e-lib/browse.cfm?elib=11265

The latter document should be found from somewhere online for free as well. It basically summarises the issues discussed in the patent in a less-confusing manner.

[Wavebourn]

http://www.diyaudio.com/forums/showt...40#post1813340

Compression sounds less nasty than clipping (when occurs).
Speaking of transistors, this output stage (complementary LTPs + VASes) donb't need an additional protection: it is self protecting. When load impedance is below the design limit it enters current drive mode:

http://www.diyaudio.com/forums/attac...amp=1240277143

[blueskynis]

Originally posted by richie00boy
You need to read Mikek's Electronics World article.

Hello,

Can you be more specific? What article?

Thanks

[andy_c]

If you shoot me an email, I can send you Mike's article on V/I limiters and the Mendenhall AES article as well.

[GK]

Originally posted by sakis
it is been very well known that classic VI limiters as exist in some amplifiers are sonic killers ....

That is only for power amplifiers too wimpy to drive the load.
The cure is basic enough - build an output stage with enough power devices to reliably drive a lower than normal impedance load.

[Steve Dunlap]

Originally posted by G.Kleinschmidt



That is only for power amplifiers too wimpy to drive the load.
The cure is basic enough - build an output stage with enough power devices to reliably drive a lower than normal impedance load.

We actually agree on something!

[GK]

Wow!

[taj]

Originally posted by Steve Dunlap


We actually agree on something!

s'cuse the novice question but... Does this just mean that if the output section is robust enough to avoid hitting the threshold of the limiter, then you don't need to be concerned about it affecting the audio?

Or are are you saying you can just do without the circuit if you have enough output devices? (I doubt that's what you meant.)

..Todd