How to make distortion?

[rodrigo_echeverri]

Guys,

There is a question in my head that tortures me. What is distortion exactly? I know if you "overdrive" a circuit, the you end up with a distorted signal. But, what has happened to that signal? Can you, say, write a computer program to distort a signal? How do you do it?

I am an engineer and for some reason I think about these things at night.. [img]images/icons/smile.gif[/img]

[ March 30, 2003, 06:00 PM: Message edited by: rodrigo_echeverri ]

[Black Mariah]

Re: How to make distortion?

Basically, distortion is caused when the tips of a sine wave are cut off. Not much more I can add to that though. You'll have to wait for Oklastrat to get here to answer your question more thoroughly. [img]graemlins/laugh.gif[/img]

[toejam]

Re: How to make distortion?

Get a razor and cut your amp's speakers up. That'll help add distortion! [img]graemlins/images/icons/wink.gif[/img]

[ March 30, 2003, 09:03 PM: Message edited by: toejam ]

[DRH]

Re: How to make distortion?

What B.M. said.

This may be a decent example. Say a preamp can put out a -2V to +2V sine wave. You plug in your guitar and while playing you measure -1V to +1V out of the preamp(won't really be a sine wave but stay with me a minute). It's fairly clean. You increase the gain until you get the 2 volts, still fairly clean, but louder.

Adding more gain should make the sine wave bigger. What happens on this preamp is the output will get bigger, but the top and bottom of the sinewave gets "clipped" to stay within + and - 2V. The more gain, the more of the wave gets clipped.

Hope this helps

DRH

[slayer]

Re: How to make distortion?

Webster`s Dictionary defines Extreme Distortion as: 1993 VHT Pittbull CLX-100 [img]graemlins/drool2.gif[/img] , it also ads carefull turning main volume past 5 [img]images/icons/grin.gif[/img] Jack [img]graemlins/headbang.gif[/img]

[ March 30, 2003, 09:26 PM: Message edited by: slayer ]

[rodrigo_echeverri]

Re: How to make distortion?

Yeah, thats clear like water. Thanks guys. A new question coming from your answers arises?

Why dont people play with that concept to make all sorts of weird digital distortion sounds. Say you played with the wave to not leave flat tops but to make the tops triangular or things like that.... am I crazy?... I think Hendrix used to think like this!.... [img]images/icons/smile.gif[/img]

[Cleveland Metal]

Re: How to make distortion?

Basically they're referring to square wave distortion.

Read this engineer oreiented sine wave stuff:

http://www.mindspring.com/~j.blackstone/dist101.htm

http://users.chariot.net.au/~gmarts/ampovdrv.htm

People do play with it digitally. It's called DSP distortion like PODs etc... Generally less pleasing to the ear than say tube oriented distortion. that's why they added a tube to the Voodu Valves DSP processing.

Something to do with the odd/even harmonics etc..

Hope this helps...

[rodrigo_echeverri]

Re: How to make distortion?

John... ahhhh!!!... fourier Analysis, now I understand... very useful links. Thanks.

[The Enema]

Re: How to make distortion?

i was wandering something like that sitting n a tech studies calss at school, when looking at simple cirsuits for distortion pedals and doing the section of the course on op amps

now it all makes sence

David

[DRH]

Re: How to make distortion?

I made some sort of distortion box years ago in college.

I basically used an Op-amp circuit for the gain stage. You could vary the headroom by controlling the plus and minus supply voltages, this would change the signal level where the "clipping" would start.

DRH

[rodrigo_echeverri]

Re: How to make distortion?

I was thinking that if you take the signal from a data acquisition card (elegant name for a sound card), you can write an algorithm to do any kind of clipping you want to the signal and then compare sounds.. that means no messing around with the breadboard!....

[DRH]

Re: How to make distortion?

Rodrigo,

that sounds like it would be a really cool project! You could write the algorithm to alter the signal coming in from your sound card and then send it back out. With a fast enough computer you could probably do it in real time.

I want to make some kind of digital delay when I have the time. An A/D converter, a D/A converter, an oscillator for the clock, some RAM and a couple of op-amps I'm good to go!

DRH