going from XLR to unbalanced, is this ok?

[Jean]

Is it okay to use shield and positive only on the XLR ? Just shorting the negative to ground and going to RCA that way.

tia

[Da5id4Vz]

Assuming a "standard" XLR configuration:

Pin 1- gnd
Pin 2- hot (+)
Pin 3- not (-) couterphase

Pin -2 tip
Pin -3 sleeve
Pin -1 sleeve (optional)

In most equipment you should be aware that you will encounter a 15 dB difference between signal levels.

Coming out of balanced and into RCA unbalanced a T-Pad works nice for padding the level down.

Going form an unbalanced (-10 dB) output to a +4 dB input may require an op amp to bring the level up if the input stage doesn’t have enough gain.

You should also watch out because there is still quite a bit of gear floating around setup for a +8dB input level reference (Sony comes to mind).

Other things to watch out for are balanced output stages that are transformer coupled will sometimes overshoot if they are fed into a high impedance input. A simple solution is to stuff a ¼ watt 600-ohm terminating resistor inside the XLR (across pins 2 and 3)cable connected to the output.

You should be careful here too that you will sometimes think you’ve made up enough gain by turning the input/output knobs up or down but may be introducing operating outside of the optimal SNR range and introducing distortion.

http://www.jensen-transformers.com/ has some great circuits and white papers showing conversions in both directions using their very high quality transformers.

-Dave