Clipping diode parameters.

[jrc4558]

Clipping threshold in the diodes. I always wondered about that when subbing diodes i nthe feedback loop of some tubescreamers I modded. Usually used additional 1N60 in series with one of the silicones, but now started wondering. What is the parameter that will define the voltage at which the diode will start clipping?
And how fast would different diodes react to the incoming signal? Is there a variability in that respect?

Thank you.

[Peter Snowberg]

The figure you're looking for is VF or Forward Voltage. This isn't so much a single voltage as a realitive description of where the "knee" in the graph is. If you look at data sheets, some of them will show a voltage drop relative to current passing through the diode.

This page is the first return from Google and is worth a look:
http://uweb.superlink.net/bhtongue/7diodeCv/7diodeCv.html

There is some speed differece, but I don't know enough to elaborate other than to say that if you need to clamp a value VERY quickly, you should go for a "fast response" diode. I don't know of any that are really slower than others amoung the everyday 1N34/1N914/1N4001 type dioides.... at least not in any kind of value that would make a difference in audio.

Take care,
-Peter

[jrc4558]

I just started thiking because I saw Mark's posting somewhere ahere he said that 1N4001 will clip at much higher voltage peak than say 1N914...
I still kinda wonder what were the original diodes in the old tubescreamer I had - pink glass, white stripe, no letters. So yeah, you can safely say that I'm on a quest for a diode.  :lol: