Best schottky diodes for clipping?

[javacody]

I got an email from Steve at Smallbear today when I inquired about schottky diodes. He doesn't carry them, but he wants to. He's asking what are the best ones for clipping? I want to use some in the black ice clipper, what do you guys think? He said that he will start carrying them if I can send him a recommendation.

[brett]

Most seem to have similar characteristics.  The 1N5819 is common, general purpose, and cheap.

[Peter Snowberg]

I use the 1N5818, but I think that the 1N5819 is the same thing with a higher PIV. Anybody done a 1N5817-18-19 shootout? I'll bet they all sound exactly alike so I would vote for 1N5819 too.

Take care,
-Peter

[Ge_Whiz]

Yeah, just go for the cheapest. In the UK that's probably the BAT46.

[brett]

I compared BAT46s and 1N5819s a while back and concluded they were identical as far as forward voltage-current relationships go.  Not surprising given their simple construction.  

(But quite different to Ge diodes where there seems to be some reasonable differences, and Si where there are small(ish) differences.)

cheers

[zachary vex]

although i don't use them for clipping, i have used 1n5817 units.

[blabj]

i know this may sound dumb but im just checking as im about to mod my guitar for a push pull version of the black ice on my guitar. question is do you use 2 diodes or one?
cheers

[Ge_Whiz]

You'll get different sounds with one or two Schottkys, both good. Try both before deciding. I actually used one Schottky and one germanium diode with a double-pole centre-off switch. One way selects Schottky only, the other selects both in anti-parallel (with, of course, centre off). If you are using a push-pull pot switch to activate only one option, I'd probably go for two diodes in AP, but it may depend on your pickups.

[blabj]

i got strat type p-ups, fairly weak out put i spose  :roll: i like the sound of using the GE diode and the scottky diode... maybe i'll use that.
cheers for your help ge_whiz

[WGTP]

What is the forward voltage (I think) for those?

[brett]

For both Ge and Schottkys the forward voltage for 1mA is about 0.3V.  Ge diodes conduct a bit down to about 0.1V, while Schottkys have a more severe cuttoff and don't conduct much below 0.2V.

cheers

[javacody]

So would ge diodes be ok in the black ice?

[Ge_Whiz]

Remember this is a passive distortion, so all you have is what the pickup puts out, and impedances are an issue. At the time of my original experiments, all I had in stock was one Schottky and a selection of germanium diodes. I tried various combinations, but using just germaniums gave a rather weedy sound. Having done more experiments since, I would probably now go for two Schottkys instead of the Schottky/germanium combo, and may yet open up the guitar and replace that germanium. But it's easy to try combinations first.

Incidentally, the easiest way to wire up a DPCO switch for two combinations and centre off is to have one diode on one side of the switch, and two in anti-parallel on the other side. However, it is possible to wire these combinations on a DPCO switch using only TWO diodes. I leave this as an exercise in wiring logic for the reader...

[zachary vex]

I use the 1N5818, but I think that the 1N5819 is the same thing with a higher PIV. Anybody done a 1N5817-18-19 shootout? I'll bet they all sound exactly alike so I would vote for 1N5819 too.

Take care,
-Peter

yes, the forward voltages are very very close at low currents, within tens of millivolts.