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Super quick Pin 1 question

Buckeye Amps

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Starting to build some simple amplifiers for sale in the US around the Hypex NCxxxMP modules and wanted to make sure my wiring was OK for XLR pin 1: On the XLR connector, Pin 1 will be grounded to the chassis (the Neutriks I use have a tab on the housing to jump pin 1 right to the chassis). For the PCB "Pin 1", it too will be grounded to the chassis, but not at the same exact point used for the XLR Pin 1 grounding.

My question: how close can these two separate grounding spots be? Can I ground the PCB "Pin 1" to one of the screws holding the XLR housing to the chassis even though XLR Pin 1 will be grounded through the XLR housing as well, albeit in a separate spot (like 1-2" away)?

Thanks!
 

Speedskater

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XLR Pin 1 is the shield not the 'ground' so while it's connected to the chassis, it's not grounded to the chassis. While 1/2 inch is best, 2 inches is OK.
 

scott wurcer

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Buckeye Amps

Buckeye Amps

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XLR Pin 1 is the shield not the 'ground' so while it's connected to the chassis, it's not grounded to the chassis. While 1/2 inch is best, 2 inches is OK.
Apologies for the terminology. So it is OK to have Pin 1 of Neutrik XLR connector attached to the chassis within close proximity, but not in the same exact spot, as where the ground pin from J6 is attached to the chassis?
 

prasanth.nath

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I had this question too (for Hypex UCD amp build). This is from the NC400 sheet.

Note: 'cable' in text means the shielded signal cable from the Amp board to chassis. The chassis is assumed to me metal (conducting).

If the cable shield is connected to chassis not at pin 1, but close by, say 1 inch away, could someone explain to me in layman terms why it is not equivalent to connecting it to pin 1 itself, as pin 1 is also connected to chassis. After all 1 inch of conductive metal is very low resistance right? How does that make the connection "better"?

What's the practical way of connecting the shield to chassis. I have tried to look at many amp builds, but I haven't been able to understand how the cable shield is connected. Most of the folks seem to connect it to pin 1.


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On a related note, is this what we should follow for the upstream pre-amp (DLCP: 6 channel with XLR out) too? The pre-amp also has signal cables from DLCP board terminating at XLR connectors on chassis.
 
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