Crackling channels on a multicore

Lisa Lane-Collins

Sophomore
Dec 9, 2012
270
0
16
Adelaide, Australia
Hellooo,

I have a crackling multicore problem. Channels 2/3 and 6/7 appear to be fine but when there is phantom power running through them and an XLR plugged in, bumping the XLR causes them to crackle like a faulty cable would.

My first port of call was to have a look inside the multicore box but everything looked pretty fine and the sockets have all been pop rivetted in, so I want to be sure replacing them is the answer before I start drilling into things. So the question is, how do I pin point the source of the problem?
 
Check for cold solder joints on pin1 (shield). If the bad channels read a higher impedance (like twice or more what other channels read) that probably is the problem. Could be dirty contacts too, which also would read high.
 
Hi Lisa, how's Adelaide?

To expand on Art's post: phantom power "works" by applying the + voltage to both pins 2 & 3 and the - is on pin 1 and drain wire/shield.

Since dynamic mics seem to work that means pins 2 & 3 have continuity as dynamic mics don't need pin 1 to operate. When you get the nasty pops and crackling with phantom power it means you've got intermittent connections with + or -.