ruffrecords

Neutrik PCB mounting 3 pin XLR connecotrs
« on: December 07, 2018, 11:36:18 AM »
In order to reduce the amount of cable soldering in mixer builds I am looking at using PCB mounted XLR connectors, specifically ones from Neutrik with metal bodies I have not yet decided whether to use the vvertical or horizontal mounting versions - there are pros and cons for each.

At the moment I have samples of the horizontal mounting versions; NC3FDH andNC3MDM3H. What I find really odd is that the plastic insert that houses the three connections is not permanently fixed to the metal outer body. This means if I were to fit the connector to a PCB and then attach the connector to a panel, every time I insert a mating connector it will simply push the plastic insert (and the PCB) out of the metal body.

I don't know if I am doing something stupid but it looks like the PCB needs to be also fixed to the panel to prevent this.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


mjrippe

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #1 on: December 07, 2018, 11:47:13 AM »
Hi Ian,

Some of their connectors have a little screw slot in the center that you have to turn 90 degrees with a very small screwdriver to connect the insert to the shell.

Mike

JohnRoberts

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #2 on: December 07, 2018, 12:08:29 PM »
I have used millions of those connectors (and have the scars to prove it..). Back in the 90s Neutrik had a design issue where the male XLR would lock in and refuse to unlock  :o I had customers literally ripping the inserts out of the PCBs, breaking the solder joints, still locked to the XLRs.  It took months to redesign the female connector and get full production quantity again. Board flexing was the least of my problems. For several months I was dodging bullets to keep production lines running for a handful of top selling SKUs.

We typically used up to a dozen or more of these connectors in small mixers and powered mixers. My memory about the specific mechanicals is a little fuzzy but such connectors require mechanical attachment to stress relieve the solder connections so the joints don't degrade over time. IIRC there may have been plastic snap in hooks/catches to mechanically secure the plastic insert to the PCB.

I would expect any mature Neutrik design these decades later to be well sorted and robust, but I haven't touched one in decades. Looking at their online catalog I don't see the exact connector we used but that is not very surprising. As I recall the female connector we used did not have a connector release lever, but relied on a snap hold in lock, and pull to release (that didn't always release in the 90s until redesigned). Instead of metal shells we had plastic rings that snapped into the chassis metal to finish off the hole.

JR
John Roberts
http://circularscience.com
Tune it, or don't play it...

Speedskater

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #3 on: December 07, 2018, 12:50:11 PM »
Over two decades ago,  Neil Muncy (RIP) wrote a paper on the 'pin 1 problem'.  It took a long time for the AES to make a small part of that paper into the  AES48 standard.  Later Jim Brown,  Henry Ott,  Bill Whitlock and others wrote about why XLR connectors should be attached to the outer metal chassis.
Kevin

[silent:arts]

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #4 on: December 07, 2018, 12:56:01 PM »
You need to interlock them:
assembly instructions

ruffrecords

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #5 on: December 07, 2018, 05:02:59 PM »
You need to interlock them:
assembly instructions

Brilliant. Almost all is clear now.

One small query remains. The PCB footprints include a 2.3mm diameter hole that corresponds with a small hole in the plastic part of the connector. What is this for?

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

[silent:arts]

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #6 on: December 07, 2018, 05:35:59 PM »
IIRC this is for a self tapping screw

ruffrecords

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #7 on: December 08, 2018, 03:27:55 AM »
IIRC this is for a self tapping screw

I guessed as much. Hate those things.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

abbey road d enfer

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #8 on: December 08, 2018, 06:16:39 AM »
I guessed as much. Hate those things.

Cheers

Ian
You don't really need to use them. I've never felt the need to, whatever the version (H or V). Aslong as there's no undue stress on the PCB.

The locking feature allows mounting the inserts on the PCB and attaching it to a panel where the shells are already mounted. Sometimes it's the only way to assemble a product.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
"The important thing is not to convince, but to give pause for thought." (B. Werber)
Star ground is for electricians.

Dan Kennedy

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #9 on: December 08, 2018, 12:12:54 PM »
I've been using them exclusively for 20 years. Very few problems.

Be sure they're latched fully at assembly. Get a really good hardened screwdriver for the latching operation.

I've never used the self tapping screw option, and to date no solder failures.

The Pin 1 issue is fairly well handled via the metallic latch components and the metal shells at assembly. Not quite
as short a path as I'd prefer, but I can put a cell phone right at the back of a unit and not hear it, so works for me.


JohnRoberts

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #10 on: December 08, 2018, 04:23:34 PM »
I've been using them exclusively for 20 years. Very few problems.

Be sure they're latched fully at assembly. Get a really good hardened screwdriver for the latching operation.

I've never used the self tapping screw option, and to date no solder failures.
For double sided or multiplayer PCB, and infrequent use they will probably ok relying on just the solder.

With single sided boards and live sound reinforcement applications where XLRs get patched and unpatched every gig, a mechanical attachment will reduce the stress on the solder joint integrity.

YMMV

JR
Quote
The Pin 1 issue is fairly well handled via the metallic latch components and the metal shells at assembly. Not quite
as short a path as I'd prefer, but I can put a cell phone right at the back of a unit and not hear it, so works for me.
John Roberts
http://circularscience.com
Tune it, or don't play it...

ruffrecords

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #11 on: December 08, 2018, 04:54:10 PM »
For double sided or multiplayer PCB, and infrequent use they will probably ok relying on just the solder.

With single sided boards and live sound reinforcement applications where XLRs get patched and unpatched every gig, a mechanical attachment will reduce the stress on the solder joint integrity.

YMMV

JR

I am curious where this stress comes from. The XLR body is bolted to a panel. The XLR plastic part is held firmly to the body by the internal mechanical fixing. These two must take the bulk of any insertion/removal stress. The PCB is soldered to fairly flexible metal struts connected to the XLR pins so it must see very little of this stress. Even less if thee self tapping screw is fitted. Or have I missed something?

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

JohnRoberts

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #12 on: December 08, 2018, 05:42:33 PM »
I am curious where this stress comes from. The XLR body is bolted to a panel. The XLR plastic part is held firmly to the body by the internal mechanical fixing. These two must take the bulk of any insertion/removal stress. The PCB is soldered to fairly flexible metal struts connected to the XLR pins so it must see very little of this stress. Even less if thee self tapping screw is fitted. Or have I missed something?

Cheers

Ian
In the value product sector the XLR inserts were not locked into a metal housing bolted to a metal chassis... more like floating inside plastic rings that snap into holes through the chassis metal.

At Peavey we had in house design rules and  Rule #1 was to never trust solder connections for significant mechanical attachment.

JR
John Roberts
http://circularscience.com
Tune it, or don't play it...

ruffrecords

Re: Neutrik PCB mounting 3 pin XLR connecotrs
« Reply #13 on: December 09, 2018, 04:09:26 AM »
In the value product sector the XLR inserts were not locked into a metal housing bolted to a metal chassis... more like floating inside plastic rings that snap into holes through the chassis metal.
OK, understood. I would have thought much of the value sector uses the all plastic version anyway in which case it is a different ball game. altogether
Quote
At Peavey we had in house design rules and  Rule #1 was to never trust solder connections for significant mechanical attachment.

JR
Yet it is amazing how many mixer modules rely on just that for attaching the front panel.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


 

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