# Crosstalk between signal lines

I'm intending to capture the signal lines of an audio mixer (XLR, 16 channels).

Each channel can be a microphone (order of mV range), or line signal (upto around 1 V).

I want all lines (16 channels x 3 XLR (GND + 2 signal lines)) to either JST or pin headers (2.54mm).

I don't know in front which will be microphone/signal lines (or at least I don't like to be dependent on it).

When I will use Arduino ADCs or other ADCs, will I get problems (like crosstalk) of I try to read a signal of a few mV next to a signal of 1V? Is there a minimum space? Or is it best to put the GNDs in between like:

Pin   1   2    3    4   5    6    7
Ch1 Ch1  Ch1  Ch2 Ch2  Ch2  Ch3...
Gnd pin2 pin3 Gnd pin2 pin3 …


So the minimum space between e.g. Ch1 pin2/3 which is 2 mV and Ch2 pin2/3 which is 1.0V is enough? (2 * 2.54 = 5.04mm) ?

• What's going to happen your balanced lines? What's going to happen if phantom power is switched on? As a matter of interest, what are you doing this for? – Transistor Nov 5 '19 at 12:07
• Phantom power will not be used. I'm not sure what you mean with balanced lines (afaik XLR is balanced?). I want to use it to 'tap' the signals later as triggering for DMX (light) equipment. So I don't need the exact signals, but just to see if there 'is' a signal (however, e.g. the bass drum signal will probably be a microphone giving just a few mV). – Michel Keijzers Nov 5 '19 at 12:10
• Also, I just want to make the connections now; still busy with first triggering DMX by MIDI (by synthesizer), but we need a patch bay very soon, so I already want to create the 'wiring' from all 16 channels now and later connect a microcontroller to use the signals). – Michel Keijzers Nov 5 '19 at 12:12
• OK, so it's sound to light. My concern about the balanced lines is that your hookup will unbalance them and may introduce noise into the mic lines. – Transistor Nov 5 '19 at 12:30
• The problem is that you will (unless you design otherwise) load one of the balanced lines and not the other. See if balanced-vs-unbalanced helps. – Transistor Nov 5 '19 at 13:08