Would be interested to see a schematic for these ...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=3718465175

or hear an opinion on them if anyone has seen/used them. Sounds too good to be true ...  :wink:

The thing about diode-based clipping is that the signal needs to be brought up to a certain level before the diode poses enough of a ceiling on how much signal can "get by them" to yield an audible clipping effect.  Germanium diodes will want a signal level of around +/-250mv to start doing that, and silicon ones about +/-500-600mv.  Naturally, that sort of signal level requirement needs some help in the form of  amplification to get what comes out of your pickup up to that level.

There do exist other types of diodes, however, called Schottky diodes, which have considerably lower signal-level requirements.  These will yield clipping with signal-levels comparable to what some - but not all - pickups produce on their own, without any assistance.  The "Black Ice" module is probably the oldest commercial product to take advantage of this, and it has been around for awhile.  I can also show you DIY circuits from "101 Electronics Projects" books from the mid-70's with the exact same idea..

As the posted information for this item indicates, however, the  device does need pickups with certain properties to function suitably.  Single-coil pickups are unlikely to generate suitable signal-levels with any consistency unless all you do is power-chord all the time or unless they are heavily overwound.  Side-by-side humbuckers, with their considerably hotter output, are more likely to produce suitable signal levels that will be clipped by the diodes.

So, yes, these work, but they only work under certain circumstances.  You can probably build your own for a Euro, if you know some suitable diodes to ask your electronics distributor for.

Ladies and gents, suggestions?

Howdy!
   I made one of these before.  This was on this site eons ago.  Someone back then came up with the "1n5817" schottky diode.
 I looked it up in my NTE Cross Reference book and this diode is definately does not have the lowest signal-level requirements.  But, the one I did find is an NTE112.

In5817 (NTE585)
Maximum peak reverse volts       40v
Max average foreward current       1amps
Ma Peak surge forward current    25amps
Max forward voltage drop             .6@10ma

NTE112
Maximum peak reverse volts       5v
Max average foreward current    .03amps
Ma Peak surge forward current   .06amps
Max forward voltage drop           .55@10ma

Hope this helps a bit!

Peace!
Arn C.

Any anti-parallel pair of Schottkys will do. Buy the cheapest.

Better still, use a double-pole centre-off switch. Then you can wire them as single diode (asymmetric clipping), off, or two diodes (symmetric clipping). This has all been discussed recently in another thread.

Sorry if I repeated an earlier thread but Im new to this and only found this site last week  :oops:

Thanks for the info though ... I'll check out some Schottky's then

Quote from: TorchySorry if I repeated an earlier thread but Im new to this and only found this site last week  :oops:

No worries.

If you search this forum for "black and ice" you'll get a lot of info.

The last time I restrung my knock-off strat, I decided to redo the tone controls. I had already modified it earlier with by taking the tone controls off the switch and changing one of the caps to make a high end only and one a standard. Both were on all the time. Anyway.... I swapped out the tone cap to the one control I was using and decided to wire a pair of Ge diodes in place of the now unused control.

I recall trying this a few years ago and not liking the results too much, but I tried it again after reading all these "black ice" threads.

This is a single coil strat copy and with the tone control down the sound is unaffected. When the control is turned up it starts to clip and with it all the way up there is a noticeable decrease in volume as the output gets clipped.

I'm liking it now with the control up about 5/6ths of the way. It adds a little grit to the neck and middle pickups. The bridge pickup has much less effect, but that cool because it only kicks in on the heavier strumming. Overall, I like it now.

Give it a try with some 1N34s or 1N5817/18/19s and see how you like it. It’s a worthy experiment.

I do like that the eBay add noted is advertising it as a mod for humbuckers where it will make the most difference, but it still works well with single coils.

Take care,
-Peter

I wasn't knocking you for re-starting the thread, just pointing out that there was more information to be had.  

Since this 'effect' is simply wired across the output of the guitar from 'hot' to 'earth', it is dead easy to try different combinations of diodes before committing some to the guitar body. Personally, I found the sound Schottkys far superior to germaniums, but it's very much a personal thing. Also, different germaniums had a significant effect on the result, whereas different Schottkys didn't.