"Brown Ice"....What on earth....?

[Toney]

Yellow snow?

http://cgi.ebay.com.au/Electric-guitar-BROWN-ICE-Overdrive-capacitor_W0QQitemZ7408520273QQcategoryZ41416QQrdZ1QQcmdZViewItem

[puretube]

Schottky...

do a search, as soon as the search-function is back to function

[Ge_Whiz]

Two schottky diodes in anti-parallel between signal and earth. Total cost... what? $1? $1.50?

[Processaurus]

"Don't take the brown ice thats been going around, folks.  And if you're experimenting use only half the volume."

[wampcat1]

Never seen the 'brown ice' before, but remember the 'black ice'? I think it was two 1n34a germaniums connected together the same as the brown ice....for like $20 or something.

[jonathan perez]

how does it work? im not quite sure i understand.

[wampcat1]

how does it work? im not quite sure i understand.

it is simply diodes that you install off of your guitar's pots, making the signal clip mildly through them first. Sounds fairly bad, IMO. 

bw

[Mark Hammer]

Okay, it's 2006 so I guess we have to repeat once more for this fiscal/calendar year...

Diodes to ground will clip the signal IF the signal exceeds the forward voltage of the diode.  Silicon diodes need a signal which regularly exceeds 500-600mv in amplitude (each half-cycle) to clip.  Germanium diodes need around +/-200mv.  Guitars will put out something like that fior a brief instant if you whack them hard and play a chord and have high-output pickups and leave the guitar volume up full.  But that's obviously not going to get you fuzz that *sounds* like fuzz.  So, distortion units have some sort of gain-adding circuit which "prepares" the guitar signal to be consistently higher in amplitude than the diode's forward voltage.  When you adjust the gain/drive/fuzz setting on your pedal, what you are really changing is what proportion of the time, you are going to "force" the signal to be above clipping threshold (hence, clipped).

Imagine, though, that you had a diode whose forward voltage was low enough that what a hot pickup put out WAS greater than the forward voltage.  If that were the case, then you could have a "gainless fuzz" circuit...which is what the black/brown ice is.

To recap...

These little 2-diode packages use diodes that have a very low forward voltage, which will provide clipping if the pickups are hot enough and strummed hard enough.  Because they are normally wired up as replacements for the tone cap (tone controls generally are wired as a variable resistor and cap to ground before the volume pot), they receive the maximum amplitude of whatever you can give them.  They WILL clip, but will not clip for a long time or hold a note the way a high gain circuit feeding a pair of Ge diodes would.  Think more in terms of "dirty sounding".  IN general, this is a potential add-on for folks with humbuckers, and not for folks with "vintage" single-coil pickups.  If you have lipstick pickups, don't even think about it.

Wiring them up to the tone pot means you can essentially dial them out of circuit.  If the diodes are directly tied to the volume pot input, then you can achieve clipping.  If there is a resistance on the part of the Tone pot greater than maybe 10k or so, I imagine you'd have to whack the strings pretty hard to get anything that had traces of clipping.

What I find amusing in the e-bay ad is the discussion of a clipping capacitor.   I understand that the clipping element replaces the tone capacitor on the guitar, but boy, talk about simplifying to the point of misleading.

[Paul Marossy]

What I find amusing in the e-bay ad is the discussion of a clipping capacitor.

What?! Talk about the blind leading the blind. 

[Mark Hammer]

My bad.  It was an overdrive capacitor.  At least it wasn't a flux capacitor.  I'd hate to hit a power chord, only to find myself in another time in history.

[cd]

My bad.  It was an overdrive capacitor.  At least it wasn't a flux capacitor.  I'd hate to hit a power chord, only to find myself in another time in history.

Because someone will ask, here's the flux capacitor schematic:

http://www.amasci.com/freenrg/bajak1.txt

[vanessa]

My bad.  It was an overdrive capacitor.  At least it wasn't a flux capacitor.  I'd hate to hit a power chord, only to find myself in another time in history.

Because someone will ask, here's the flux capacitor schematic:

http://www.amasci.com/freenrg/bajak1.txt

What? I thought the real time travel circuit was this:

http://www.freeinfosociety.com/electronics/schematics/audio/pictures/fuzzfacenegative.gif

[Connoisseur of Distortion]

hmmmmm...

where can we buy +/- .01% capacitors? 

[brett]

Furthermore, one can go back to the future of tone in a Fuzzface with a germanium Q1 and a silicon Q2, but not if they are the other way around.  This is an imutable law caused by the lower quantum energy "gap" between N germanium and P germanium.

[Nasse]

Don´t  eat yellow snow

[dano12]

My bad.  It was an overdrive capacitor.  At least it wasn't a flux capacitor.  I'd hate to hit a power chord, only to find myself in another time in history.

Flux capacitors are the key tonal ingredient in the ZVex Fuzz Factory, and my "Analysis and Schemeatic of the ZVex Fuzz Face" article pretty much proves it: http://beavisaudio.com/Projects/fuzzfactory.htm