Which Schottky Diode

[MmmPedals]

I am building a Doubler. It is a fuzz pedal with an octave switch. It has 2 sets of diodes which i believe are schottky (see thread "name those diodes and diode substitutions"). which ones should i try first? or will any work so i have to try them all and see what sounds best?
The first set is in the signal path coming from the base and emitter of a transistor (maybe for octave). the second set is in a loop to ground near the end of the circuit (clipping?)

[slideman82]

I only know 1N5817, 1N5818 and 1N5819, the difference is its size... would go for the smaller ones.

[JKowalski]

There sure are alot of diode topics sprouting up randomly this past week  

I think most schottkys have around the same voltage drop so I think they will all pretty much do the same thing.

[bumblebee]

Some big muffs use 1N6263. They are the same size as a 1N4148.

[slideman82]

Really? Which models would be? They'd sound more compressed!

[bumblebee]

Some later issue 2000 3003- Revisdion A ones. I have two that uses them.

The current one is 3003- revision C and uses 1N4148 so you'd have to find and old one as they do differ in parts and values quite a bit.

The revision A was made from 2000-2007 then revision B came in for a VERy short time, then the 2008 revision C came out which is easily the nicest sounding modern muff of them all IMO, the best since the 3034 (also one of their best IMO). SOunds just like the tone wicker muff without the tone bypass and wicker.

[jcmorse563]

along these notes how much diffenece would it make to swop the 1n6263 to replace the  1n5817.. ?? had any one tried this, or should i just wait for my order of 5817s

[artifus]

if i were interested i would google for datasheets and compare spec's and tolerances.

[Mark Hammer]

Would I be terribly wrong in suggesting that the areas where differences emerge between many different diodes within a given class of diode are often at those frequencies that have absolutely no bearing on audio?  For example, they may be around current handling, or switching time, for currents well above, or frequencies well above, what would normally occur in the stompbox world.

[artifus]

...differences in guitars, pick ups, fingers, playing styles, subjective perception...

[jcmorse563]

ok then, Ill through them in there and let you all know......  sorry need my liver.

[Earthscum]

I've played with a few different Schottkey diodes, and I haven't really been able to discern much audible difference. When using them for clipping, I have noticed a slightly sharper tone with 1N60P's, and those are MY preference, but honestly the difference is is probably negligible to anyone but me.

[jcmorse563]

thanks...

[Earthscum]

Just to clarify something, using schottkey diodes for clipping and using them for octave-up circuits are different things. Like I mentioned, for clipping there isn't much difference in sound. When it comes to octave-up, it depends on the implementation, but most octave effects work best with the lowest forward voltage possible. Since Schottkey diodes are (always?) silicon junction, they should all be fairly consistent in our audio applications, like what Mark was saying.

[GGBB]

I picked up a bunch of different Schottkys to test as the half-wave rectifier in an Orange Squeezer.  Impetus was a post by Jon P (midwayfair) that mentioned the necessity of a low forward voltage diode for this circuit to function best, plus the scarcity of the original 1N100 germanium and common replacement 1N60, and the general sense that a 1N34A Ge is okay but not great.  So I hunted out Schottkys, and comparing datasheets they pretty much all state 1V max.  But a close inspection of their graphs shows that forward voltage drops with current (and temperature), and they are not all the same down in the millivolt range.  Haven't really done those tests yet, but I did measure the diodes (diode setting on DMM) to compare forward voltages and found that 1N5817s are notably lower than BAT48s which are a little lower than BAT41/43/46 which were all a little lower than 1N34As.  I don't know how important Vf is for octave-up applications, but I would think it would matter for clipping.  I also don't know how the DMM measurement translates into real world applications - maybe this is all moot as Mark suggests.

[jcmorse563]

well i just built the keeley katana clone from tagboardeffects.  didnt have a 10u cap so  i put a 1u didn't have a 150n so i put a 100n, didn't have 1n5817's so i put 1n6364. didnt have a 2dpdt so i used a 3dpdt, (i think posts 1-6 are the same.)   everything else as the instructs say.. and hey it works,, sort of.. more like a distortion pedal.. lots of clipping at upper levels, and overdives my little amp pretty bad.. don't know which part is doing it but , will work with it as was looking for a  clean boost.   Im thinking that the in the dpdt sub something is off as the volume know seems to control even the clean bypass.      back to the drawing board...

[jcmorse563]

oops the 1n6263 i mean...

[mistahead]

There's a flood of diode clipping fuzz pedals for "preorder" this week too (in the recesses of the interwebs).

I have no faith anymore lol.

[jcmorse563]

turns out the the overdrive effect was from my little practice amp.   Pedal works great this those diode. sound good with lots of range.  thanks... next is the keely 4 knob comp clone.... see u there.

[Digital Larry]

Maybe this is sacrilege, but if you're worried about forward voltages for things like full wave rectifiers, why not just use an op-amp in an active circuit?

such as:

http://www.play-hookey.com/analog/feedback_circuits/full-wave_rectifier.html