Voltage regulators as AGC?

[g3rmanium]

Hello,

had this whacky idea in the morning: Could I use a voltage regulator (say 1.5 V) as an AGC circuit?

Johann

[Paul Perry (Frostwave)]

I doubt you could use one as an AGC device. But as a clipper? Or a distortion device?
I suppose it all depends on how the regulator behaves when it doesn't have enough headroom. ( a 5V reg for example might want 6 or 7V input before it actually gives a regulated 5v out).
plus you have asymmetry to contend with...(or take advantage of!)

[Sir H C]

How were you thinking of using one as an AGC?  As Paul says, maybe a clamp, or limiter, but AGC is usually more of a VGA with a loop around it to keep the RMS constant.

[g3rmanium]

How were you thinking of using one as an AGC?  As Paul says, maybe a clamp, or limiter, but AGC is usually more of a VGA with a loop around it to keep the RMS constant.

I don't know if there are RMS voltage regulators, but why not rectifying the signal, amplifying it and then using a voltage regulator to keep it at around 1.5 V or so...

[soulsonic]

So you want to turn your guitar signal into a 1.5v DC supply?

If you want to make a heavily distorted signal that has a constant level - the best choice I can think of is a comparator. If you put your guitar signal into a comparator, the output will be a constant-amplitude square wave at the maximum voltage available to the circuit. So you could run it at 1.5v, or just use a voltage divider to cut it down to 1.5. Either way, it will be constant. I built comparator-based fuzzes before and they can sound really good in a big buzzzy synthy kinda way.

[g3rmanium]

So you want to turn your guitar signal into a 1.5v DC supply?

No I just want to remove most of the dynamics. I was looking into JFET-based AGC circuits once and they looked simple but maybe something even simpler exists?

If you want to make a heavily distorted signal that has a constant level - the best choice I can think of is a comparator.

Mh that sounds interesting, too. Do you have a circuit diagram?

[Paul Perry (Frostwave)]

No I just want to remove most of the dynamics. I was looking into JFET-based AGC circuits once and they looked simple but maybe something even simpler exists?

You need to distinguish between clipping (just cutting the tops of the notes at some fixed level) and compression/sustain (detecting the signal level & controlling the gain on an amplifier stage to try to even out the average level.
First approach is simple but gives enormous distortion.

[g3rmanium]

You need to distinguish between clipping (just cutting the tops of the notes at some fixed level) and compression/sustain (detecting the signal level & controlling the gain on an amplifier stage to try to even out the average level.
First approach is simple but gives enormous distortion.

I know, I know. I thought that maybe a voltage regulator can do the same as a compressor, just simpler.

[magikker]

I have to say I am really curious about this... I'd love to hear sound clips with one of these doing the clipping.