Tube Screamer

doug4350 · 21 May 2006

Hi R.A.,

Maybe this can get you started.

http://home.hawaii.rr.com/doug4350/Tube_Screamer.osm

It's my first attempt beyond "Hello World!" at it 🙂 .

I know the maths aren't up to snuff, but it's just to get the concept across... (not to mention the time)

The example code:

streamin sin; streamout sout; float finv; float pfvd, nfvd; float ceiling, floor; float pthresh, nthresh;

pfvd = 0.3; nfvd = -0.3; ceiling = 1; floor = -1; pthresh = ceiling - pfvd; nthresh = floor - nfvd;

finv = -1.0 * sin; finv = (finv > 0) & (pthresh + (pfvd * finv)) + (finv <= 0) & (nthresh - (nfvd * finv)); sout = finv;

hopefully is intuitive enough to get the basics across. It's for the inverted clipper. The var's pfvd/nfvd are for the pos/neg diode voltage drops. Ceiling/floor are the headroom. Pthresh/nthresh are (supposed to be) the voltage drop thresholds, but there's an error. finv is the inverted signal at the sample point.

The .osm has a sine & some other osc's to fiddle with, but you'll need to disconnect & reconnect to not freak out the graphs.

I've left off the biasing maths for r1&2, and the diode/op amp characteristics. I've run out of mental horsepower atm to track that down.

Hope this helps... Aloha, Doug[/url]

rullyastronout · 23 May 2006

thanks doug, this is nice method,...i really don't have clue with electronic 2 digital methode. ill try out.

thanks

sambean · 24 May 2006

Could this help....

http://magalov.myweb.hinet.net/waveshaper/WSdemo.osm

😀

Sam

rullyastronout · 24 May 2006

excelent, ......sam...., ill try