Kit, Safety String Ground for Stratocaster, SonnyW Brand

Kit, Safety String Ground for Stratocaster, SonnyW Brand
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  • Item #: 2035

String Ground Safety Modification Kit for Stratocaster And Similar Guitars

When properly installed, limits fault current from mains through strings to < 1 milliamp in case of ground or polarity fault. (1 mA limit is about 30x safety factor)  Fits in Tremolo cavity. Will not affect tone or normal function of string ground to reduce hum.

Kit Features:

  • Assembled unit consists of .001uF 3KV Capacitor and 220k ohm 1% metal film resistor in parallel with soldered mil spec tefzel insulated 22awg lead wires
  • Replaces string ground wire in your guitar or bass, connects to tremolo claw (or in some cases to bridge)
  • Short lead is approximately 5-6 inches long, Longer lead approximately 12 inches
  • Solder Lug included (if needed)
  • Installation instructions included
  • Each individual kit assembly is fully tested at line voltage for fault current with test results recorded on package
  • All components fully enclosed in heat shrink for insulation if installed in control cavity or to prevent any potential rattles.

Many guitars use a string ground to reduce hum and noise.  With most all modern amplifiers this is now relatively safe, but with some types of unmodified vintage amplifiers and in some stage situations where the mains polarity could be reversed there is a danger of the strings becoming connected to the hot side of the mains. Some older amplifiers do not have isolation through the power transformer or may even have a switch to reverse the polarity – to reduce hum.  If the player then touches the strings at the same time as any grounded object such as a mike stand, railing, another amp, or sometimes just the bare floor, there is a danger of electrocution.

Tragically, this hazard has resulted in the deaths of several performers. It's more common than you might expect. Keith Relf of the Yardbirds, John Rostill of the Shadows, and Les Harvey of Stone the Crows are a few that didn't survive, not to mention many other big name players that have had brushes with death. Keith Richards was probably saved only by his hushpuppies, and Ace Frehley was knocked unconscious and had to be carried off stage. He wrote a song about it "Shock Me".  This kit will not prevent a fault current from happening, but will limit any current to a non-lethal amount if it does occur.  The hum reducing function of the string ground and the guitar’s tone will not be affected.

Most authorities consider 30 milliamps as the lower limit of current through the body needed to cause injury.  This is the amount that will cause ventricular fibrillation (the heart stops).  About 1 -5 milliamps of current is considered the threshold of pain. Properly installed, this kit will limit a direct short circuit current to approximately 0.5 milliamps at full 117-120V line voltage. (see test photo) Any current through the person’s body would be less than that due to skin resistance and conditions etc.  The voltage will remain approximately the same, but the maximum current through this path is limited. The small maximum current is still plenty to ground the strings properly yet not enough to pose a safety risk to your body.

If you own a guitar with an unprotected string ground, consider making this simple and inexpensive modification. It is excellent insurance against becoming famous in one of the hardest ways possible. Why so many factories don't do this to begin with (though some do) is a complete mystery to me.  Price includes shipping by first class mail.

Installation Instructions


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Price $5.95
Availability In-Stock

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