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fporfidio@opton
01-26-2008, 08:42 PM
hi guys, i've been using jbl pro stuff for30 plus years now and i've still got the same question i had years ago-has anyone ever heard of a reason/GOOD reason for jbl pro to be black (positive)?????

johnaec
01-27-2008, 07:12 AM
Quoted from this doc: http://www.jblpro.com/tech-library/JBL_TechNoteN1V12C_v5.pdf

"As we can best determine, the original polarity decision had been made by Lansing on an arbitrary basis."

More info in that doc.

John

edgewound
01-28-2008, 10:38 AM
Quoted from this doc: http://www.jblpro.com/tech-library/JBL_TechNoteN1V12C_v5.pdf

"As we can best determine, the original polarity decision had been made by Lansing on an arbitrary basis."

More info in that doc.

John


That could very well be....arbitrary, that is.

The explanation that I've heard from some old timers...and a conversation by phone some 19 years ago with Hal Cox was one of them...was that in the very early days of theater sound the installers were electricians. The hot lead on 110/120 volt AC circuits is black, with neutral being white.

Early Altecs have screw terminals with no color.