Diode Question

[Heavyriffing]

Is Diodes In Pedals usally used for creating the distortion sound?

[Mike Burgundy]

This is one of the ways to clip a signal, yes. Mostly done by sticking a diode pair (back-to-back) either from signal to ground (Distortion+), or in a feedback loop of an opamp (Tubescreamer).
The trick is that diodes need a certain voltage before they start conducting. Anything below that voltage is not affected, above it it's clipped. By using two diodes back-to-back you ensure both halves of the signal get clipped.
There's loads of other ways though. Welcome to the DIY community - fancy a build?
PS: Try tyhe DIY FAQ and RG's FAQ (linked above: http://www.geofex.com/effxfaq/fxfaq.htm). There's also a distorion 101 in there. Good stuff.

[MartyMart]

Hi,
Diodes do have many uses, in a "pedal" circuit, such as protecting the reversal of battery terminals etc.
You normally see them used in a pair, or a few pairs on each "gain" stage to provide "clipping" as part of an overdrive/distortion circuit.
Small "copper" coloured silicon versions are either 1N914's or 1N4148's
the larger "black with silver band" versions are "power protection diodes" (1N4001-1N4007) and can also be used in a pair or one together with a 1N4148/1N914 for a different flavour of "clipping".
LED's ( 5mm or 3mm ) can also be used for clipping in this way, as they too are "diodes".
Have  look in "simple mods and tips" for some more useful info.
Cheers,
Marty.