Cable Shield Conducts
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Do it Yourself
Cable Shield Conducts
Cable Shield ConductsFrom detritu--(at)--x.netcom.com Sun Nov 25 20:19:04 CST 2001 From: Lord Valve Newsgroups: alt.guitar.amps Subject: Re: Guitar cable/severe attenuation...WHAT's Up??????? Date: Sun, 25 Nov 2001 15:27:32 -0700 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Server-Date: 25 Nov 2001 22:24:57 GMT Xref: geraldo.cc.utexas.edu alt.guitar.amps:371498 MBarnett wrote: > "j.k." wrote: > > > I bought some Horizon Studio-1 bulk guitar cable. I bought 2 straight > > 1/4" switchcraft plugs to solder onto the ends. > > > > The cable itself is about 20 feet and I soldered on the plugs and I > > have what definitely appears to be nice clean soldering. > > > > So I plug it into the 'ol Marshal hi-gain amp and WOW!...the sound is > > severely attenuated. I have the gain cranked and it sounds like a > > very mildly clipping sound. Low noise, but no full guitar output into > > the amp. > > Have you measured the resistance or done a continuity check of the > cables? I ran into an interesting problem hacking up a Peavey cable into > several shorter ones a few months back: Seems there was a conductive sleeve > (black) on the outside of the center conductor's insulation (translucent > white). If ANY of that black sleeve came in contact with ANY of the center > conductor, I had a short (either direct or high-resistance) to the shield. > Once I realized I was dealing with some "new-fangled" cable, I just trimmed > the conductive sleeve back and all was right with the world. (Or at least > with my cables!) > > Monte Lord Valve Speaketh: OK, Monte nailed it. The "black sleeve" around the center conductor is an electrostatic shield; cable designed expressly for guitar use usually has this. In some cases, it's conductive plastic (Canare, Mogami) and in others it's cloth (Belden and other "old school" wire makers). You *must* remove this when making cables. The cloth kind is easiest to deal with, because you can force the tip of an awl (or similar tool) between the cloth and the center conductor's insulation, and then rip downwards, cutting the sleeve off with your nippers when you reach the point where the center conductor enters the braid. For the plastic type, I like to gently bite it with my Miller 103-S strippers (any pro-quality strippers will do; the Miller is the kind I like) and just strip it off like insulation. Doing it like this takes a little experience, since it's important not to nick the insulation underneath. Once you have the electrostatic shield removed, you can just solder the cable in the regular fashion. The electrostatic shield is a high- resistance conductor, which is why you get attenuation when it touches the center conductor; it's exactly the same as connecting a resistor between the shield and the hot lead. The reason this shielding is there is to keep the cable from making skritchy-scratchy noises and thumpy-slithery sounds when it slides around on the stage. Many a rookie has decided to make himself up a guitar cable out of some leftover mike wire and found out the hard way that lo-Z cable doesn't work worth a shit in that application. Miles, I believe I have an old post I saved dealing with this; I'll shoot it to you and you can decide whether it should reside in the AGA FAQ. No fair peeking, Glum...you *know* there isn't anything worth reading on the AGA site...right? ;-) Lord Valve Tone Chaperone VISIT MY WEBSITE: http://www.nebsnow.com/LordValve I specialize in top quality HAND SELECTED NOS and current-production vacuum tubes for guitar and bass amps. Good prices, fast service. QSC amps, RNC compressors, lots of other good stuff! NBS Electronics, 230 South Broadway, Denver, CO 80209-1510 Phone orders/tech support after 1:30 PM Denver time at 303-778-1156 VISA - MASTERCARD "In a time of universal deceit, telling the truth is a revolutionary act." -George Orwell-
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