Audio interlinks
How do you go from a 3.5mm stereo jack on your laptop to an XLR3 female socket in the church wall that links up to the PA system?
This has plagued me for a while now, and my first attempt at solving this problem involved connecting a 3.5mm male to an Amphenol XLR3 male from Dick Smith using 4-core shielded audio cable. Basically the tip and ring were connected to pin 2 of the XLR connector, and the sleeve was joined to pins 1 and 3. This didn’t really work as there was significant background hum for some reason.
Next tried a few adaptors and cables. Went from the 3.5mm stereo socket in the laptop, connected via a standard 3.5mm male-male stereo-stereo cable to an adaptor that turned a 3.5mm stereo female into a 6.3mm (6.5mm, or 1/4″) mono male, which then fed into another adaptor that converted the 6.3mm mono signal into an XLR male connection to feed into the wall. But that created hum as well.
Which got me thinking about the shielding, since the shielding in the first cable wasn’t connected at all, and the shielding in the second cable was non existent.
Did a bit of searching, and found something similar to do with an RCA going into an XLR3 male. The solution that worked in the end was to feed the tip and ring of the 3.5mm male through two cores and join them at the other side, soldering them together to pin 2 of the XLR3 male. The sleeve was fed through another core and was connected to pin 3. Finally, the all-important cable shield was soldered only on the XLR end to pin 1. This solved the hum issue, and the stereo signal coming from the 3.5mm socket in the laptop could be hooked up straight into the church PA. Nifty.
