RE: Making cables (hope this isn't OT)

[goddard.duncan@mtvne.com]

Title: RE: Making cables (hope this isn't OT)

>>I have about 30 meters of cable (Canare L-4E6S) which a sound guy recommended for making cables. It is shielded and has four wires (two pairs) in the core. The connections I?m making are between my echoplex, G-major, preamp, power amp, drum machine and computer to mixer, as well as some balanced microphone cables. I?ve heard and read conflicting stories of the correct way to make cables. Yesterday the man at the place where I bought the plugs told me that I should use both wires from one of the pairs for the tip and the other pair for the sleeve, leaving the shield unattached at both ends. That didn't sound right.<<

it isn't. the cable you have there sounds like "star-quad" or similar, designed to bring extra benefits to the principle of balanced cabling.

for the balanced cables you make (& remember you'll only see the benefit of using balanced wiring when the equipment at either end of the cable supports it), use the overall shield to the shield connection, & treat the two pairs of inner wires  as one wire each. they go to tip & ring, or hot & cold in y'r XLR connector. there's a reason why the two wires in each pair are twisted together..... it improves the rejection of unwanted noise coming from outside the cable. y'r man got that bit right....

unbalanced is easier. you can either ignore one of the inner pairs or join it to the shield at both ends. use the other inner pair as normal.

there /are/ situations where one might leave a shield connection off at /one/ end- trying to deal with a ground-loop without interfering with the mains wiring would be one such. but your guy at the store has it wrong.

>>Can I make MIDI cables with the same cable?<<

yes- again, treat each inner pair as one wire. connect shield to the middle pin of the DIN plug at both ends, & the inners to the two pins immediately to it's left & right, keeping the orientation the same at both ends. don't connect anything to the outer pair of pins unless you are sure these pins are unused in the equipment. I use these connections to carry power around but that falls outside the midi standard.

hth-

duncan.

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