Racking TAB V372DS questions

[drummerman1515]

I am racking two TAB v372ds modules - 4 channels total.  I have them passing sound but I have a grounding issue I need to diagnose and maybe something else with one channel.  Before I try to tackle the grounding, I wanted to make sure I am not making a mistake wiring the connectors. 

Each module uses two 31-pin connectors.  There are multiple pins for 0v, 3 pins for shields and 1 pin for ground.  I have all the 0v connections coming back to the negative post on the power supply.  If that is correct, to clean everything up, can I jump all of the common 0v connections at the connector so I have one 0v wire back to the power supply 0v?  What do I do with the 3 "shield" pins (I'm thinking these will connect to all of the input/output grounds)?

After reading about the grounding, I plan take all of the XLR pin 1 grounds to the module connectors rather than to the chassis.  From there, take the module grounds (pin 30) to 0v on the power supply and place a switch in series to the chassis ground connection (for a ground lift). [https://groupdiy.com/index.php?topic=14147.0] I'm hoping that will solve the grounding issue, but I want to make sure I haven't made a mistakes making the connections to the 31 pin connectors.

Much thanks in advance.

Schematic:  http://audio.kubarth.com/rundfunk/getfile.cgi?f=%3B%2C38P.%23%28V-C8R-E%5DV%2BW1A8E%5DV%2CS%3CR9%27%2CN%3AG%21G%0A

 

[drummerman1515]

Also, this is what I have for the pinout:


Connector A

1    +24v
2    0v

11  Shielding [“abschirmung schirm”]
12  Shielding
13  Shielding
14  0v

17  to Pin 1 of connector B
18  to Pin 2 of connector B
19  Input 1 +
20  jump to 21
21  jump to 20
22  Input 1 -
23  0v
24  Output 1 +
25  jump to 26
26  jump to 25
27  Output 1 -

29  0v
30  Ground
31  +24

Connector B

1    from Pin 17 of Connector A
2    from Pin 18 of Connector A

10  0v
11  0v
12  0v
 
14  jump to Pin 20
15  jump to Pin 21

17  0v

20  from Pin 14
21  from Pin 15

 

[radardoug]

You can use an ohmeter to see if the 0v pins are connected together. If so, you only need to run one 0v cable from the power supply to the module. I would suggest use pin 2 or 29.
Any pins that are not connected need to be connected, but it can be done at the module.
The sheilding pins, connect them all to chassis ground. Also ground the 0v line to chassis.
Put a 100 ohm resistor from each XLR connector pin1 to chassis ground. Parallel it with a .1 uF cap.
You can do it on the XLRs if they are Neutriks.
This gives you a slightly floated ground at low frequences, and a low impedance ground at rf frequencies.
No need for a switch.

 

[drummerman1515]

Thanks radardoug!  I will get to work and report back!