Crimp vs Solder XLR: Experiences wanted

[Remoteness]

Interesting; we never ground the shells.

[mpdonahue]

We never ground the shells of our XLR's either. Causes WAY more problems than it fixes. It's one thing to tie the shells together with a separate conductor (Like the old Gotham cables) or through an RC network (Like in properly wired splitters) but connecting it to pin one is a no-no.

All the best,
-m

[chris319]

Originally Posted by mpdonahue

We never ground the shells of our XLR's either. Causes WAY more problems than it fixes. It's one thing to tie the shells together with a separate conductor (Like the old Gotham cables) or through an RC network (Like in properly wired splitters) but connecting it to pin one is a no-no.

What problems does it cause?

[radeng]

Originally Posted by chris319

What problems does it cause?

Can cause ground loops.

[JEGG]

The issue of connecting shells has been talked about for a long time-a couple or few generations-maybe more.

The cons cite ground loop issues. This really depends on the circumstances of where you record (or do PA work). That's something you'll have to answer yourself-but it's fair to say I think, for most people it might be better to leave them unconnected-the industry standard is to leave them unconnected.

Though I quit following the discussions some years ago on the Neumann site, they advocated connecting the shells. And if not connected, at least connect the one (only) at the mic end. This seemed to be particularly important with cell phone issue, especially but not exclusively regarding the KM18X series. At about the same time, I did once have a phone conversation with one of the engineers from Germany based here in the US regarding connecting the schell at the mic end.

Reasons:

1. For connecting only at the mic end. Surface to surface contacts can behave very differently at RF frequencies than at audio frequencies or DC. Because of the way the mic body is (or was) ground referenced, there are advantages to be gained with that arrangement. Anyway-connecting even one shell at the mic end was strongly advocated for cell phone problems. (This info from phone.)

2. For connecting all: (this information not so much from the phone call, but from discussions on the Neumann site)
Neumann intended a specific cable type (traditional Gotham/Neumann arrangement) to be used with their mic's. I understand it, but someone else can explain that succinctly! Connecting the shells was part of that system.

Most people did not (and don't) use that cable system, and the design intended for the "old way" didn't necessarily work well (in terms of RF) with the simple way most of us work now.

About a year after the introduction of the KM18X series, they changed some mic electronics to deal more effectively with RF. I don't know if that also involved changing the system that worked optimally with the "old style" cable system. I would guess they still advocate all shells connected, regardless of cable system used.

At the time-remember this was years ago, they favored the Switchcraft design for XLRs.

Of course, one would have to assure that there were no possibilities of ground loops.

The majority of my cables do not have the shells wired in, and I haven't had any problems, even in circumstances where others have. (Knock on wood)

Have others of you noticed preferences expressed from other manufacturers? DPA, Schoeps, etc.?

Oops-we may be straying from the thread.

Now back to connection technology..........

[JEGG]

Originally Posted by chris319

Good news #1 is that the connections are soldered. Good news #2 is that they are not gold contacts. The bad news is that the shells are not grounded. I like my shells grounded, so I have some work to do on these.

thumbsup Feel better now? And why not leave the shells ungrounded, unless you're having a problem or you can't live with the idea of having them unconnected?

[tenor39]

I'm not saying that gold plated contacts are bad, just that they require special care in soldering to them. ALL of my location audio cables and snakes use gold plated connectors. Silver plating oxidizes and tarnishes in the elements and creates connectivity issues unless cleaned on a regular basis.

[mpdonahue]

The thing to remember about the Gotham wire is that it had 3 jacketed conductors and an overall shield. In these cables, the hot cold and ground were all individual conductors and the shield/screen was used to tie the connector shells together.
If you want to learn more than you ever wanted to know, look up the AES standards paper on it (AES48) or read the Rane interconnection documents.
All the best,
-mark

[LX3]

Originally Posted by tenor39

I'm not saying that gold plated contacts are bad, just that they require special care in soldering to them. ALL of my location audio cables and snakes use gold plated connectors. Silver plating oxidizes and tarnishes in the elements and creates connectivity issues unless cleaned on a regular basis.

Actually, I'm sure I recall Neutrik saying that although the silver plating on their XLR connectors tarnishes over time, it actually has no effect on the conductivity when mated. It just looks "dirty".

[Boschen]

Originally Posted by tenor39

Ben is right. The major issue with connector failure is the strain relief. The chuck style of the Neutrik is far superior to the older Switchcraft XLR's with their screw clamps.

Yes, the next failure point is a cold solder joint. I've seen this more and more in the Chinese knock-offs of the Neutriks. The inferior metals used in the pins readily oxidize and the rosin flux in most electronic solders will not clean them well enough to alow the solder to adhere to the pin. Stay away!

Another issue with soldered connectors is the gold plating in the better connectors. Yep, the very thing that prevents the pin from oxidizing can cause joint failure in the soldering process. When I worked for a NASA/Military cable and harness company, we had to first fill the cup with solder and then suck it out before soldering the wire into it. The gold plating will leach into the molten solder and create joint problems if this is not done, along with the need for adhesion to the base metal of the cup. This is how ALL connectors and cable assemblies are done for the military and NASA.

Crimp connections can be fine for audio connectors IF the right tool is used and the clamping force is adequate to create a cold weld. I've done such assemblies for the above mentioned company, but the tools were $$$$ and the procedure was then inspected under a microscope to determine its effectiveness. Companies like ProCo and the Chinese use them because they are cheap and much less labor intensive. Finally, never use an IDC! They might work for automotive wire splicing, but I'd never trust one for any audio I was passing through it.

This is the way I make my cables, by tinning the wire and solder cup first, then making the join. Like several other posters, I also make the ground shorter, so it is less likely to fail first. I also try to 'memorize' the wire so that it lies correctly in the collar of the connector, and minimizes strain on the solder work.

I took a neutrik connector I'd made like this, and whip-snapped it against a concrete block a half dozen times. It was a male end, and the housing bent in, but the solder points were fine (this destruction came about because of a wager, of course...).

I prefer soldered pins also because of universal ease of replacement. Sheesh, we just agreed on the hot pin, and now we're going to change the connectorizing method?

[mixedupsteve]

Another potential problem with connecting the shield to the shell is if it is connected to both shell and pin 1 at both ends a ground lift switch wouldn't work.

[tenor39]

Originally Posted by LX3

Actually, I'm sure I recall Neutrik saying that although the silver plating on their XLR connectors tarnishes over time, it actually has no effect on the conductivity when mated. It just looks "dirty".

Not so. Why offer the Gold plate if this were true? Let's look at the conductivity of the metals in question.

Let's begin with some resistivities for the materials being discussed. Resistivity is the opposite of conductivity so the smaller the number, the less intrinsic resistance (greater conductivity) it possesses.

Copper: 1.7 X 10^-8 ohm-m
Silver: 1.6 X 10^-8 ohms-m
Gold: 2.4 X 10^-8 ohms-m
Silver Sulfide: 1.5 to 2.0 X 10^-3 ohm-m
Silver Oxide: 1 x 10^+9 ohms-m

So, the Silver Oxide, although conductive, is 6,250,000,000,000,0000 times higher in resistance compared to Silver.

As others have said, if you're in a controlled atmosphere enviornment, Silver plating is fine. But for remote work I'll choose the Gold plated connectors if given a choice. BTW, the dissimilar metal argument is really only valid if the connection stays in place for an extended period of time.

[drummerboy_al]

I've been following this thread. My question to all of this would be - So what type of solder to use then?

The reason I ask is b/c I've heard conflicting statements in the past (not here) and I don't want to spend a ton on solder. I know that a rosin core is preferred. Though I'm still not 100% on the logistics. I noticed that there is an "RA" for the flux type on the solder that i have (63/37) - and planned to use. Does this mean Rosin/Acid? If so, is acid bad?

I know how to solder pretty well, but I've never payed too much attention to the type of flux that's in the solder itself. I'm about to take on a massive mic cable/snake soldering project this coming weekend...just trying to get my ducks in a row here

[JEGG]

Originally Posted by LX3

Actually, I'm sure I recall Neutrik saying that although the silver plating on their XLR connectors tarnishes over time, it actually has no effect on the conductivity when mated. It just looks "dirty".

I've waited to add this anecdotal response until someone with real knowledge did so first. And tenor39 has.

So here's the anecdotal stuff: If you have silver plated contacts with obvious oxidation (or even non obvious oxidation), the results of cleaning can be remarkable-more important to surfaces that are left in contact for relatively long periods of time, or those infrequently used.

Also, confirming a closed circuit with a common circuit tester or meter in those situations won't provide much information about how the contacts perform in use.

[MicDaddy]

for squeaky clean connectors

[MichaelPatrick]

Originally Posted by drummerboy_al

I've been following this thread. My question to all of this would be - So what type of solder to use then?

The reason I ask is b/c I've heard conflicting statements in the past (not here) and I don't want to spend a ton on solder. I know that a rosin core is preferred. Though I'm still not 100% on the logistics. I noticed that there is an "RA" for the flux type on the solder that i have (63/37) - and planned to use. Does this mean Rosin/Acid? If so, is acid bad?

I know how to solder pretty well, but I've never payed too much attention to the type of flux that's in the solder itself. I'm about to take on a massive mic cable/snake soldering project this coming weekend...just trying to get my ducks in a row here

The solder you have is perfect for audio connectors.

From http://www.elecraft.com/TechNotes/N0...derNotesV6.pdf ...

RA = Identity code for a flux which contains rosin with additional activators to enable soldering of difficult substrates. Although an RA-based material, the residues are not-corrosive if left uncleaned.

63/37 or 60/40 is the content, or Tin-Lead (Sn-Pb) ratio

[drummerboy_al]

Thanks for the info (the pdf is great). Good to know that I don't have to spend a ton on solder.

Originally Posted by MichaelPatrick

The solder you have is perfect for audio connectors.

From http://www.elecraft.com/TechNotes/N0...derNotesV6.pdf ...

RA = Identity code for a flux which contains rosin with additional activators to enable soldering of difficult substrates. Although an RA-based material, the residues are not-corrosive if left uncleaned.

63/37 or 60/40 is the content, or Tin-Lead (Sn-Pb) ratio

[boojum]

Finally, I have pictures of the Neutrik solderless connectors which I am using.

The first pic is the Neutrik exploded but still assembled. Straightforward and easy to see how it all fits together.

The second photo is of the assembly itself with a small screwdriver inserted into one of the two locking tabs in order to open up the assembly.

The third pic is the assembly partially open. Note at the center a knurled surface on a plastic finger. This holds the cable from being pulled out. Tugging on the cable forces the knurled tab down harder onto the cable, tightening its grip. At the upper right end of the assembly locking cover there can be seen two deep set slots. The tabs holding the copper wires fit up onto these slots further securing the copper wires.

The fourth pic is looking down into the XLR. The gold pated tabs with their narrow slots can been seen with the copper wires jammed into them. On the side is a similar tab to hold the ground mesh.

The construction insures that the wires are held in a tight connection, that the wires are clamped in place by assembling the locking cover and that the cable itself is secured against strain. Pretty neat design.

Sorry to have taken so long to post the pics. I "lost" my camera in my gear bag.

[chris319]

Originally Posted by mixedupsteve

Another potential problem with connecting the shield to the shell is if it is connected to both shell and pin 1 at both ends a ground lift switch wouldn't work.

You could make a ground lifter out of 6" of mic cable and connect only pins 2 and 3.

[rcrowley]

IMHO, the primary issue with crimped connectors is the solidity of the connector pin (or socket) in the insulating base as well as the strength of the pin. Solder-type connectors have pins that are molded into the plastic during manufacture. While crimp-style pins are very thin sheet metal held in place with nearly microscopic "barbs". And typically they are removable, which means that they are never permanently fixed into the connector shell.

Now the crimp-style female sockets are similar between solder cup and crimp style, but some brands of male pins are hollow tubes and MUCH more fragile. In smaller connectors (like DB25, etc.), and especially those in relatively permanent installations, these differences have little potential for failure. But for XLR connectors, and especially the "rolled pin" style, I actively avoid them. If I were going to use crimp pins, I would, at minimum, insist on the solid "screw-machine" type vs. the stamped metal variety.

[Viccy]

Well, I follow mostly an organic diet. So does that mean I should also avoid nasty chemicals and ill health by using solderless connections.

Just wondering because today I bumped into an old-school technician who was coming back from the doctor after a check up on his lung condition which was caused (it is believed) by countless hundreds of hours of soldering in professional studios.

Hmmmm.

[claying]

Originally Posted by Viccy

Well, I follow mostly an organic diet. So does that mean I should also avoid nasty chemicals and ill health by using solderless connections.

Just wondering because today I bumped into an old-school technician who was coming back from the doctor after a check up on his lung condition which was caused (it is believed) by countless hundreds of hours of soldering in professional studios.

Hmmmm.

I always wear mask when soldering.
For maximal protection, get yourself an N95 or N100 industrial mask to do the work.

[mpdonahue]

Or you could use a fume extractor or a good old fashioned fan...... How do you think the folks that spend 40 hours a week soldering manage to survive...
All the best,
-mark

[Remoteness]

Yes, a good old fashion fan pulling the fumes away from you (and others) is indeed a great idea.

Originally Posted by mpdonahue

Or you could use a fume extractor or a good old fashioned fan...... How do you think the folks that spend 40 hours a week soldering manage to survive...
All the best,
-mark

[mfischman3]

Fan and/or extractor and a solid mask (keep on top of the filter replacements) are essential if you're doing this full-time.

Even working lead free has its hazards. And, if you really want to stay heathy and have a base line for future comparison, doctor's visits with a blood test will let you know if anything unhealthy is really going on long-term.

[Fuzzy Logic]

i have use a 3" fan attached to a long 3" hose for many years. it works very well for me.

[MicDaddy]

A small inline fan setup remotely that pulls through a carbon filter that we setup next to iron holder/work station does help keep smoke out of your face.

[boojum]

I never had to do a lot of soldering. I built a few kit amps way back and some small stuff. But I kind of liked the smell of rosin-core. I guess it is good I did so little soldering.