Suggestions for Clipping Diodes

[toddvirgil]

I'm putting together a PCB that will allow me to dial in various clipping options in a typical symmetrical or asymmetrical clipping path. Also thinking about offering this as a project for sale to the community when I get it done.

I'm hoping you guys can throw some diode suggestions out there... I'm thinking about having 10 different positions for each diode in the path.

1n34a, bat 41, bat 46, etc....

Thanks!

Todd

[billstein]

Jon (midwayfair) did a great post on different clipping diodes. Listed a bunch of them. I'm away from my computer and on a phone right so it's hard to search for the link. Maybe somebody else can help with that.

[ddog]

Here is that post:

http://www.madbeanpedals.com/forum/index.php?topic=5399.0

[alanp]

Best option is for massive changes between positions, like Si/Ge. Not 1n34a/1n270 or something. But I'm a hugely unsubtle person at times.

[midwayfair]

This is every clipping option that might make a noticeable difference in a circuit capable of generating a signal large enough to drive all of them. This is a lot of options and not even all of these are going to be noticeable in a typical circuit.
1. ge/ge
2. Ge/si
3. si/si
5. single MOSFET
4. led/si
5. led/led
7. MOSFET <-> MOSFET [For clarification, these are in series, connected at the sources]
8. Lifted
9. Any particular option above + a series resistor (softens clipping)
10. Any particular option above + a series capacitor (frequency-specific clipping)

[Jabulani Jonny]

Geez Louise.  Todd, give Jon your lunch money, he just did your homework.   

[toddvirgil]

This is every clipping option that might make a noticeable difference in a circuit capable of generating a signal large enough to drive all of them. This is a lot of options and not even all of these are going to be noticeable in a typical circuit.
1. ge/ge
2. Ge/si
3. si/si
5. single MOSFET
4. led/si
5. led/led
7. MOSFET <-> MOSFET [For clarification, these are in series, connected at the sources]
8. Lifted
9. Any particular option above + a series resistor (softens clipping)
10. Any particular option above + a series capacitor (frequency-specific clipping)

John, as always, awesome. I'd send you my lunch money if you sent me your address, haha.

Just to clarify, I'm basically going to put 4 rotaries, two in each opposing path (so you could go symmetrical with single device on each side, assymetrical or two devices in series one ach side), with a switchable pot for clip softening and a block to put a capacitor into. Should be fun. Mainly I'm looking for specific component names  -- what are your go-to favorites? If you're doing si or germ, what's your favorite?

[midwayfair]

Mainly I'm looking for specific component names  -- what are your go-to favorites? If you're doing si or germ, what's your favorite?

I've have to know the circuit in question to give specifics. I wouldn't get hung up on specific component names. Just worry about cost, availability, and Fv.

You can get a ton of millage out of never buying anything except the following:

Ge
1N270 (alt: D9E, Russian, which is cheaper, or any number of other russian detector diodes) = Fv .25-.30
1N34A (these are common, but get the from a reliable source) = Fv .35

Schottky
1N60P (super cheap) = Fv .2-.25v
1N5817 (consistent, good for revere polarity and envelopes) = Fv ~.2
BAT41 (real ones ... get them from a reliable source) = Fv .35V (I may be wrong and it may be BAT43)

Generic silicon
1N4001 = Fv .5
1N4148/1N914 (same thing) = Fv .6

LED
Red, Green, and Blue

Zener
3.3V (asymmetrical silicon clipping with one diode)
4.7V (crude 1/2 supply voltage)
9.1V/12V (input voltage clamps)

[toddvirgil]

Thanks Jon! Good stuff. I'll send you a board when I get em fabbed if you're interested.

Any other mosfets besides the 7000 that work well?

[midwayfair]

Any other mosfets besides the 7000 that work well?

I prefer the BS170. They are quieter when used as amplifiers. Get both though and decide which one you prefer. Their Fv are different.

[toddvirgil]

Cool, thanks again Jon.

[billstein]

I know this isn't my thread but thanks Jon for all this great info. You answered some questions I've had for awhile.