Automatic attenuator

[Claudio Carbone]

I have a lighting device, that reacts to sound (vulgarly called
psichedelics).
Now my biggest problem is that, from the preamp, not all songs come out at
the same level.
The light console has a pot (it is homemade) in series with the input, to
attenuate the level.
What i could use is some sorf of circuit, with a manually selectable
threshold, that automatically starts attenuating the signal when this same
signal goes above the threshold.
I looked at limiters and compressors, but for what i understood these do not
apply to my case: the compress the dynamic range, something i want to avoid.
I want to apply the same attenuation to all the signal, just to maintan the
same mean value.
I hope i have stated it clearly enough.
Anyone can help me?
Thanks
Claudio

 

[CWatters]

"Claudio Carbone" <gino@pino.com> wrote in message
news:cm321d$q6k$1@lacerta.tiscalinet.it...

I hope i have stated it clearly enough.

Yes. You need an ACG circuit (Automatic Gain Control)...

http://www.discovercircuits.com/A/autogain.htm

Home page...
http://www.discovercircuits.com/list.htm

 

[TheDragon]

http://www.designnotes.com/CIRCUITS/agc.htm

 

[Claudio Carbone]

CWatters wrote:

Yes. You need an ACG circuit (Automatic Gain Control)...

Thanks
Claudio

 

[BobGardner]

What i could use is some sorf of circuit, with a manually selectable
threshold, that automatically starts attenuating the signal when this same
signal goes above the threshold.
I looked at limiters and compressors, but for what i understood these do not
apply to my case: the compress the dynamic range, something i want to avoid.
I want to apply the same attenuation to all the signal, just to maintan the
same mean value.
I hope i have stated it clearly enough.
Anyone can help me?
Thanks
Claudio
=======================

Compressors and limiters are synonyms for automatic gain controls. You just
want a compressor with adjustable compression ratio and adjustable attack and
release time.... like almost all of them have.... set a nice mild compression
ration like 2:1... output goes up 1 db when input goes up 2db... set the attack
time real long... set the threshold so the gain reduction leds are just
operating.... Should hold the volume over a wide range of input levels....