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Cave Passive Pedal company...

Posted: Wed Sep 08, 2010 5:31 am
by avj
I came across a site earlier today, Cave Passive Pedals.

A snippet from the site about the pedals:
Cave Passive Pedals wrote:Passive technology is nothing new. The volume and tone controls on your guitar or bass are passive. Some amplifiers are equipped with a passive “tone stack�, bass-middle-treble controls. The idea of passive overdrive has been with us for years. The concept of two diodes facing opposite directions, wired in parallel across the output terminals of an instrument creates a usable, but sometimes volume dropping, fuzz or “crunch� sound. Even a Ring Modulator effect that disrupts the signal to an unrecognisable bell like tone, is a passive device from the 1950’s.

So what makes Cave Passive Pedals so different?

We have taken vintage technology and improved its capabilities. We feel there was a “gap� left in time. When every electronics engineer focussed on creating smaller components, more efficient, portable power supplies and eventually, the digital revolution, the passive world took a massive step backward, plunging towards near extinction! If the human race had of realised that passive electronics had a long and exciting development ahead, that many things are possible without the use of a power source, would they still have given it up?

“Crystal sets� have long been forgotten. To receive radio transmissions without the need for 240 volts or a pack of 1.5 volt batteries would blow most people’s minds of today. Even more bizarre would be the concept of “wireless transmission of free energy� that Nikola Tesla was prevented from giving to the world! Imagine, never having to worry about finding a wall socket or changing flat batteries. Where ever you went, your radio could keep playing...indefinitely! All this is possible with vintage technology!

Here at Cave Passive Pedals, we are trying to fill the gaps. We have taken a step back in time to bring you, the musician, what should have been. We are the first to re-establish passive electronics in a world that refuses to believe that nothing can be achieved without a power supply.

Heath Cave – Chief Designer
And here are some video demos.

This seems like some genuinely cool stuff. The prices look pretty reasonable, but not all of the pedals are demonstrated on the site and there isn't much in the way of independent YouTube demos.

Posted: Wed Sep 08, 2010 6:17 am
by Will
Needs better demos.

Most of it just sounds like some low forward-voltage Schottky diodes. Sort of like the old Black Ice passive overdrive.

The "signal booster" is probably just an inductor making a frequency boost, like the Varitone.

The light based phaser is using the motion of your foot to vary resistance in a band-pass filter stage. Just like a regular phaser without an LFO (and probably only 2 stages).

They're neat experiments, but most will have a pretty bad signal drop. I mean, have you ever heard a crystal radio? They worked, but were barely louder than a whisper.

Posted: Wed Sep 08, 2010 6:31 am
by avj
Yeah, I found a pretty comprehensive discussion here before I posted:

Passive clipping circuits - with Schottky diodes