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How to Solder: An Illustrated DIY Guide to Making Your Own Cables

466K views 11 replies 1 participant last post by  Wayne A. Pflughaupt 
#1 · (Edited)



Most enthusiasts who frequent this and other home theater forums are no doubt familiar with the Canare do-it-yourself cables that use the company’s proprietary crimp-on RCA connectors. Did you ever wish there were an alternative that didn’t require expensive tools? Well, there is: The old-school soldering method.

Now, I’ll be the first to agree with what the fans of crimping tell us, that their method requires no special skills. They’re right: Crimping is straightforward and idiot proof. But once you’ve made the cables, what are you going to do with those proprietary crimping and cable stripping tools? After all, you can’t use them for much of anything else.

It’s here that we see the distinct advantage of soldering over crimping. Most of the tools needed are inexpensive generic items that you can use for all kinds of projects. In fact, you may already have some of them in your toolbox. Even the soldering iron itself doesn’t cost much. A suitable iron can be had for less than a quarter the price of the Canare tools. A nice variable-heat soldering station, a considerable upgrade from a basic iron, is still about half the price of the Canare tools. Like the other tools, a soldering iron can be used for projects other than audio/video cabling. For instance, once I soldered a couple of wires from my garage door opener remote to a switch on the dash of my car. That put an end to fumbling for the remote every time I came home. Just one example of what you can do with a soldering iron and a little imagination.

The only downside to soldering is that some people apparently can’t do it. However, if you have the ability to do intricate work with your hands and have a keen eye for detail, you can probably solder. All you need is the proper instruction – that’s why we’re here!

Soldering can be tricky and intimidating, but it’s easy to understand in theory. It’s technically defined as a process of joining metals by fusion and solidification of an adherent alloy. The adherent alloy, or solder as it’s commonly called, has a relatively low melting point in the range of 350-400° F. The most common solder used for DIY cables and other electronics-related work is a rosin-core, 60/40 tin/lead alloy. Much as external fluxes accomplish with other welding processes, the rosin is a cleansing agent that removes oxides from the surface of the metal that would interfere with the molecular bonding of the solder. Typically only non-ferrous metals like nickel, brass, silver, gold - and of course copper - can be soldered, at least with the type of solder used for electronics applications.

The soldering process involves heating the surfaces of the metal pieces to be welded, typically with an electric soldering iron, to a temperature above the melting point of the solder but below their own melting point(s). When the metal pieces reach the proper temperature, the solder can melt and "flow" via capillary action into the joint and bond the pieces together. The rosin aids in the process by allowing the solder to flow smoothly. When the solder cools and solidifies, you have a sturdy bond that is extremely robust. Robust enough, in fact, that when cables and connectors are subjected to undue stress or abuse, the wire itself will physically break before the soldered connection fails.

Once you know how to solder, you can make just about any kind of cable you might have a need for. Need an RCA to XLR cable to connect a BFD equalizer to your receiver and subwoofer? No problem. How ‘bout a 3.5 mm stereo to dual 1/4” plugs, like if you wanted to connect an i-Pod to a sound mixing console? I don’t even know if you can buy such a cable, but you can sure make one! If you have a store-bought cable that quits working, no need to discard it. You can clip the RCA off the bad end and install a new one.

You can also terminate in-wall wiring for your home theater installation and save a lot of money. It’s far cheaper to buy spools of bulk cable and loose connectors than long lengths of custom-made, pre-terminated cabling. Not to mention, running and dropping bare cable inside walls is infinitely easier with non-terminated cabling.


Choosing a good cable

Naturally, if you’re going to take the trouble to make your own cables, you might as well make good ones. This means using quality materials, as not all cable is created equal. But how do you know if the cable you’re considering is any good?

I suppose I have a advantage over many people in this department. Back in the 90s I spent several years as an installer for a sizable full-service pro audio company – “full service” meaning we did not only permanent installations in places like churches, recording studios and concert venues, but also sales, equipment rentals, and sound reinforcement for live shows (including national tours for big-name acts). One of my duties when installations were slow was making repairs to all the cables that came back damaged from the shows and rentals. So as you can imagine, I’ve cut up more cables and spent more time hunkered over a soldering station than anyone should ever have to. Not to mention making up from scratch any kind of unusual audio or video cable that an installation might require.

The side benefit of a gig like this is that you learn to recognize what separates the good cables – and connectors – from the junk. That said, I certainly don’t pretend that anything I have to say on the subject should be taken as “the last word” – you are certainly free to cut up a few hundred cables and decide for yourself. Just kidding. In all seriousness, it should be obvious that my experience is limited to whatever came across my work bench and the installations I worked on.


Internal / external construction
Cabling pro or novice, we are all familiar with the skinny, generic cables supplied with most of the components we buy, and even a novice might rightly assume they are as cheap as it gets. But don’t assume a cable is better just because it is thicker. Thicker cable can be functionally just as bad, or even worse than the generic stuff. It’s what’s inside – under the outer jacket - that counts.

All audio and video cabling will have an insulated center conductor housed inside a metallic shield. If there is more than one center conductor, better audio cables will intertwine other filler materials with the conductors, such as strands of cloth or plastic, to help the cable maintain a round shape. (However, this will generally not be the case with installation-grade cabling.) Here is a picture of a cable with the outer jacket stripped back, showing the shield, center conductors and filler materials:


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Courtesy of Canare Cable


Typically, shields come in three types. A multitude of tiny, individual strands of wire arranged into a braided or spiraling configuration are the most common shields used in the cabling we use in our equipment racks, while a foil-wrapped shield is most commonly seen in the installation-grade wiring used for (logically) permanent installations.



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Braided shield
Courtesy of Mogami Cable


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Spiral shield


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Alternative spiral shield
(each conductor shielded separately)

Courtesy of Mogami Cable


Kitchen utensil

Foil shield
Courtesy of Parts Express


Braided shielding is generally thought to be superior to spiral, but in my opinion that’s not an iron rule; there are certainly some excellent examples of spiral-shielded cable available. My rule of thumb for a good shield is pretty simple no matter what the type: If it’s dense enough that I can’t see the center conductor underneath, I’m a happy camper.

Here is an example of a poorly-made cable with an inadequate shield:


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As you can see, the cable is fairly thick, which immediately gives a good impression. But take a closer look at the end, where the outer jacket is stripped back. See the copper and black spirals? The black is the insulator for the center conductor. The copper is the shield. That’s right – the shield is loosely wrapped, not fully covering the center conductor. And what’s there is really thin. Bad, bad, bad.

This particular cable is a balanced mic cable. You can probably get away with a marginal shield with balanced audio signals because it’s a protocol with outstanding noise rejection properties. Not so with the unbalanced signals we typically use for home audio. For us, the shield is what makes or breaks noise rejection properties, so it must be substantial and robust. It may surprise the reader to know that the cheapie cables that came free in the box with your DVD player are actually better from a functional standpoint than the one shown above. At least they have a decent shield, even if their connectors are marginal.
 
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#2 · (Edited)
Materials
In addition to a good shield, the materials and physical build of a cable will also define its quality. For instance, as audiophiles we naturally prefer oxygen-free copper for both the center conductor and shield, since both carry the audio or video signal.

A supple outer jacket and high strand count of both the shield and center conductor(s) will affect the perceived quality of a cable - i.e., the more strands, the more flexible the cable is, which is generally a desirable trait. Having a pliable cable that feels nice to the touch goes to aesthetics more than electrical function, but really - who wants an electrically-excellent cable that’s all stiff and gnarly? Fortunately, you’ll generally find that most quality cables will look and feel the part – at least those designed for in-rack use (don’t expect installation-grade cabling to be aesthetically appealing).

The material used to insulate the center conductor is important as well. The center insulator is typically some kind of nylon- or plastic-like material. Such materials are not terribly resistant to heat, but they need to be able to withstand enough for us to complete the soldered weld. I’ve seen cables where the insulator could not withstand heat and would melt away before the soldering could be accomplished, leaving the center conductor bare and exposed. That’s a recipe for a future short circuit. It’s fine if the insulator gets a little soft where it’s close to the soldering iron's tip, but it should remain essentially intact long enough to complete the weld. (By the way, if a lot of this isn’t making sense, it will when we start soldering.)


Capacitance
A subject that often comes up with high performance cable is capacitance. Many custom cable makers prefer and recommend for audio uses specific cables that have very low capacitance specifications. However, capacitance is largely a “per foot” issue – i.e., more of an concern with long cable runs than with short. As such, in your equipment rack capacitance is virtually a non-issue because the lengths are so short. Long cable lengths are typically going to be in-wall and by building and/or electrical codes will require installation-grade stock, which precludes the use of anyone’s preferred ultra-low capacitance cabling.

Is this to say that the cables from Blue Jeans and other makers are not worthwhile, or worth the money? Of course not – they use excellent supplies and materials, so you’re getting a first-class product. I just don’t think ultra-low capacitance specs or true 75-ohm RCAs (which we’ll discuss in Part 2) are truly needed in most home theater applications. It’s kind of like feeding your pet T-bone steaks when he’ll do just fine on Dog Chow.

Downgrade a bit to more “regular” cabling and RCA connectors and you’ll find that there are plenty of excellent choices available for a very reasonable price. For instance, the cables we will be making will cost about 1/4 of what Blue Jean’s stereo interconnects sell for. Or put another way, their cables are four times more expensive.

This isn’t to say that capacitance need never be considered. If you are able to discern audible differences between various interconnects, you might want to go ahead and use low capacitance cabling. Or, if you’re using longer-than-usual cabling – say, more than 10-15 ft., it might be a worthwhile consideration (subwoofer cable runs excluded).

Cable recommendations

Audio
I typically recommend a two-conductor, balanced cable – also known as mic cable - for audio interconnects. For one thing, it’s easy to find well-made cable of this type. Mic cable also offers an advantage that regular single-conductor cable can’t, namely there are a couple of options for configuring it.

For instance, the dual center conductors can be tied together at both ends when soldering to the RCA. This makes for a more reliable and durable cable: If one conductor fails for some reason, the other retains continuity and the cable still works.

The other option is tying one of the conductors into the shield. This results in the signal (+) and (-) traveling on the center conductors, which are twisted internally through the cable. According to theory, the signal (+) and (-) traveling on twisted pairs further aids noise rejection.

Canare's L-2T2S is a first-class, pro-grade mic cable that you can’t go wrong with, and it’s very economical. Like other Canare mic cables, it has an especially robust, tightly-woven tinned copper braided shield – great for minimizing noise, although more difficult to work with than a spiral shield (never fear, we’ll show you how to deal with it). Some vendors even sell the L-2T2S cable in colors. How cool is that? A red cable for right and black for left, if you’re so inclined.

Canare’s L-2E5 is one of my personal favorites for home audio use. Canare bills it as a “low profile” cable, which is merely a fancy way of saying it’s good bit thinner than the L-2T2S, or most other premium audio cable for that matter.

Don’t be put off by the smaller diameter - actually, there’s no good reason for the audio cable we usually use in our equipment racks to be as thick as they are. The larger diameter is merely achieved by making everything thicker, from the internal center conductors and insulators to the outer jacket. A heavier-duty cable is great to have say, on a stage where they get yanked around and heavy things run over and fall on them. But for home audio, where cabling generally suffers no abuse, it’s really overkill. So if you want to reduce some of that clutter behind your rack, go for the thinner L-2E5. It’s also a little cheaper than the larger L-2T2S (although unfortunately not available in colors). Here are the two Canare cables side by side so you can see the difference in diameter:


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Canare L-2T2S (top) vs. L-2E5 (bottom)


Mogami is another excellent brand, well known to audio professionals but not so much to home theater enthusiasts. Some Mogami cable features a spiral shield, which (as noted) is much easier to work with than Canare’s tightly-braided shield. The downside is that Mogami is more expensive than Canare. Mogami’s spiral-shielded 2549 is a favorite of mine. It’s a bit more per foot than the Canare L-2T2S, but I can turn out a mic cable using 2549 in 30% less time than it takes with Canare L-2T2S or L-2E5's tightly-braided shield. So if you have a lot of cables to make, it’s probably worth the time saved to spend a little extra for the 2549.

I don’t have a lot of experience with Belden cable, although I know it’s an excellent brand. If you prefer Belden, I expect you can’t go wrong with any mic or video cable they offer in the price range of the Canare or Mogami offerings.

Perhaps you’re wondering, why not use regular single-conductor audio cable? Well, it’s hard to find some with the build quality of the Canare and Mogami mic cable. Canare does sell a couple of single conductor cables, the GS-6 and GS-4, billed as a guitar and instrument cable, as does Mogami. I’ve never used them, but I’m sure they are good cables. However, there usually isn’t much price difference between the single conductor and the mic cable; I’d just as soon use the latter with its inherent benefits of increased durability and configuration options.


Video
Video is more demanding than audio, which makes cable selection more critical. Typically you want 75-ohm cable for any video application, be it composite, S-video or component. For composite or component, it’s hard to beat Canare’s LV-77S, which also happens to be the cable used by fans of the DIY crimping system. It’s a dual-shielded RG-59 coaxial with a stranded center conductor (a rarity in coax) that helps make it more flexible than standard RG-59. A more economical alternative is the single-shielded LV-61S, at less than half the price of the LV-77S (there’s not much cause for a dual-shielded cable in our domestic settings). Like the L-2T2S mic cable, the LV- cables come in a variety of colors, which would be cool for component video. (NOTE: The LV’s can also be used for audio, although I expect they won’t be as supple and pliable as the mic cable.)

To be honest, I’ve had excellent results using plain-vanilla RG-59 for video applications. It kinda goes against my “if you’re going to make your own cables, make good ones” mantra, but RG-59 is so cheap it’s certainly worth a try, especially if you’re talking about in-wall wiring to a projector or wall-mounted flat screen TV. Just make sure you use some with a copper shield, and if it’s for consumer component video or commercial RGBHV, make sure all cables are cut to exactly the same length. (NOTE: I recommend RG-59 over RG-6 because it is much more rack and installation-friendly, since it’s thinner and more flexible. You often hear of RG-6’s improved bandwidth capabilities, but that only applies to radio frequency [RF] signals from satellite and CATV feeds, not line-level audio or video signals.)



Please direct any comments and questions to this DIY cable discussion thread.
 
#3 · (Edited)
Part 2: Choosing a Good RCA Connector



Do you really need a bulky, high-priced connector?

When you go shopping for RCAs, you’ll quickly discover that their prices vary wildly. You can find connectors from under a buck all the way to $50 or more – each. The pricey ones are certainly impressive looking – big and bulky, gold plated knurled barrels, the works. Here are a few examples from what I call the “Hall of Shame” – or maybe it would be better called the “Hall of Shameless”:


Cable Electronic device Technology Electronics accessory Font

Clear Audio Smart PMC - $16.00 pr.
Courtesy of Take Five Audio


Cable Electronics accessory Electrical connector Electronic device Technology

Dayton RCAX-AU - $22.00 pr.
Courtesy of Amazon.com


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WBT 0101R -$49.00 ea.
Courtesy of Amazon.com


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WTB Nextgen Platinum - $80.00 ea.
Courtesy of Amazon.com


Are these RCAs really worth prices like this? And aside from the proliferation of precious metals (who knows, maybe next year we’ll see some that are diamond-studded), what are you getting for your money?

To answer that, perhaps we should take a giant step back and confront a basic reality: In the world of connectors, RCAs are bottom feeders. Anyone who has spent more than ten minutes around any kind of professional-grade electronic equipment – audio, video, broadcast, telecommunications, laboratory, military, you name it – knows that good connectors have built-in locking mechanisms, to (a) insure that they are seated properly, and (b) to prevent them from being accidentally unplugged. You don’t get that with RCAs - or any other connector used for consumer applications, for that matter.

Then there is the impedance issue. The sad truth is, most RCAs are 25-ohm connectors – even lower grade than most of us realize. Most audio cabling is 50 ohm, and good video cable is 75 ohm, so it’s not hard to see where the weak link in our signal chain is. So, manufacturers of RCA connectors can bulk-up and precious-metal-plate all they want, but it’s like putting lipstick and silk on a sow: at the end of the day the RCA is still a low-end connector.

And we have to ask: What will you be plugging those expensive RCAs into? Anyone think the jacks on a typical receiver or DVD player are up to the build quality of a $45 plug, or even a $3 one? Get serious. It’s standard-issue, dime-for-a-dozen stuff straight from the mass-manufactured parts bin. Here’s what the RCA jacks in your receiver look like under the cover:


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Stock OEM RCA Jack Assemblies


Another beef: These days the back panels of home theater receiver are a virtual sea of RCA jacks, accommodating all the gear we use in our systems. Am I the only one who has noticed that most “hi-grade” RCAs are so fat that you can’t unplug those in the center of a row without first unplugging all the others above or below?

Folks, there is no functional need for an RCA to have a barrel so fat you can’t get a good grip on it. Typically you’ll find the makers of expensive connectors to be the “kings of bulk,” but not always – I’ve also seen relatively economical RCAs that were overly bulky as well. It may be difficult to find a good RCA that has a thinner-profile barrel, but it’s certainly a worthwhile effort to seek one out.


Do you need a 75-ohm RCA connector like Canare’s?
While I prefer soldering to Canare’s crimped RCA system, I will give them credit for raising the bar for the lowly RCA. They claim their RCAP plug is a true 75-ohm connector. This is accomplished because the RCAP is crimped to the recommended LV-77S or LV–61S coaxial cable in the same manner that F-connectors are crimped to standard coaxial cable. This is significant: F-connectors, like the RCAP, are designed to keep the shield intact and fully surrounding the center conductor at the point of termination. This maintains the cable’s impedance from end to end, a feature that is impossible to accomplish with a soldered connection.

In addition to its unique design, the RCAP is a solid, well-built connector that’s reasonably priced. And it’s not overly bulky. But just how necessary is a 75-ohm connector for our various audio and video applications?

Canare claims that regular RCAs are “ ...virtually unusable for 6 MHz broadcast video frequencies, high bandwidth RGB video monitor lines, or even digital audio data bit streams.” Personally I find that statement a bit disingenuous. For one thing, we all know that 75-ohm video cables with regular (25-ohm) RCAs work just fine for the latter – we’ve been using them for over 10 years with our DVD players. As for the former and median, high bandwidth signals are the stuff of professional video and broadcast equipment, where twist-lock BNC connectors are the standard – not RCAs. In other words, any equipment that operates with high-bandwidth signals – audio, video or otherwise - won’t use RCA connections, period. Our home theater equipment simply does not fit that bill. If and when that changes, the connectors will change, too (HDMI for instance).

In the meantime, regular (25-ohm) RCAs are just fine for audio or video. I’m told by reliable sources that the input and output impedance of the video circuits in consumer products are not tightly controlled. Thus it should be obvious that any impedance mismatches you’ll have with a soldered RCA are insignificant compared to the variances in terminating impedance in the source and destination components. So there’s no good reason to feel short-changed because we can’t use the 75-ohm Canare RCAP for our soldered DIY cables.

That said, over the years I have seen some people claim they noticed a visible improvement in picture quality with their DIY Canare cables. So if you have high-grade video equipment, it might be worthwhile for you to go the Canare route, although in reality HDMI has rendered RCA-based cables obsolete for high-definition video signals.
 
#4 · (Edited)
How to tell good RCAs from not-so-good
Let’s take a look at a few RCA plugs I have accumulated in my parts bin over the years to determine what separates the quality connectors from the cheap ones. (Some have been previously used, so please pardon the latent solder residue.)

We’ll start with a look “under the hood” of a common RCA and diagram it so you can get familiar with the terms we’ll be using. I couldn’t find anything on-line about the proper names for the various internal components of an RCA, so I had to create my own. Float these terms with the staff at Blue Jeans or other cable makers at your own risk. :D

The tip and solder cup have continuity for the cable’s center conductor; the sleeve and arm have continuity for the shield connection.


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RCA Dissected


Here’s an example “under the hood” of an RCA that's heavier-duty than the one pictured above. Note that the cable will pass through the frame of the connector, and the cable clamp is a set screw.


Pen Office supplies Cylinder


First up, let’s look at an absolute bottom-of-the line connector. This one is sold by Radio Shack, but I’m sure there are other vendors who carry the same kind. (Sorry for the coupler, folks – it was necessary in order to pose the connector in the proper position once the barrel was off.)


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Radio Shack #274-319


As you can see, this RCA has not only a plastic barrel, but a plastic body as well, with metal termination points - i.e., the cup and arm. Actually, there is no cup, just a metal tab for the tip connection. Which in and of itself isn’t entirely objectionable, but frankly I find the prospect of heating up with a soldering iron termination points that are embedded in a plastic body to be a pretty scary proposition – so much so I’ve never bothered to use one of these. Perhaps one of our readers has more courage than I do.

Next up is another budget connector. Radio Shack also sells this one, but many other vendors carry essentially the same connector.


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Radio Shack #274-339


This is a fairly cheaply-made connector. It’s hard to tell from the picture, but the arm/clamp assembly is light-gauge metal and extremely flimsy. The minuscule cable clamp will fully wrap around only the smallest of cables, not something more substantial like our preferred cable stock. Also problematic is the absence of a “scoop”-styled solder cup for the center conductor. Instead, as the bottom picture shows, there is a hole that the center conductor slips inside. I won’t go into details as to why this is undesirable, since we haven’t got to the step-by-step soldering instructions yet, but trust me – inexperienced DIYers should avoid an RCA like this. It is much, much easier to solder a plug with a “scooped” solder cup.

Here is an example of probably the most miserable RCA plug ever made, strangely enough from Switchcraft, an otherwise highly respected manufacturer.


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Switchcraft #3502


The problems with this RCA are numerous. As you can see from the side-by-side picture, it’s a very diminutive plug. Much as I like thin-barreled RCAs, this one is just too little of an otherwise good thing. In everyday use, its tiny barrel gives you practically nothing to hold on to (due to its short length) when you connect and disconnect it from equipment. The minuscule barrel also means that quarters “under the hood” are really tight as well, making it difficult to solder. The cable entry hole in the barrel is really small, so you are limited to using thin cable. Yet despite that, the cable clamp isn’t large enough fully clamp around even a low-profile cable like the Canare L-2E5.

If all that weren’t enough, the center conductor is designed to stick all the way through the hollow tip and soldered at the end of the tip! (Note the hole in the end of the tip.) As you will better appreciate when we get to the soldering instructions, that means you have to strip back at least 1-1/8” of shielding, which is nearly four times as much as is usually needed. If you’re using braided-shield cable, and especially the tight-braided Canare cables, you’ll quickly find this is needlessly time consuming and tedious.

Last up, a fairly popular connector from Radio Shack.


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Radio Shack #275-850


This is certainly a nice looking RCA, but the arm and cable clamp are light-gauge and rather flimsy. Overall, Radio Shack’s Gold RCA is so-so connector that’s overpriced for what you get. Other connectors can be had from Dayton, Neutrik and Canare for the same or less money that are much more substantial.
 
#5 · (Edited)
Recommendations for an RCA plug
As you can see with the connectors above, I’ve used quite a few RCAs over the years, and naturally I’ve settled on a few favorites. To sum it up, I’m looking for a gold-plated plug, well-made with substantial internals and as thin a profile as possible. Oh yes, and a reasonable price. I’m not paying a king’s ransom for a low-end connector that’s going to be plugged into a 5¢ jack.

Nicely meeting these criteria is the Neutrik Rean NYS373 plug that Parts Express and other vendors sell. You can’t beat the price, typically under $2 each. In addition to plain black, it comes with color-coded heat shrink sleeves for typical applications – red, white or yellow, even green and blue versions for making component video cables (if you didn’t use color coded Canare LV-77S cable).


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Neutrik NYS373


Please note that the NYS373 does not have a traditional crimped cable clamp. Instead there is an unusual independent chuck-style clamp that’s not physically attached to the arm. It is slipped over the cable, and when the barrel is screwed on it tightens the chuck’s grip, evenly applying pressure to all sides of the cable’s circumference. Soldering this connector is a breeze, since there is no cable clamp attached to the arm to get in the way. As one positive review on the Parts Express web site puts it, the NYS373 looks like it was designed with installers in mind.

In addition to the excellent stress protection supplied by the chuck, the NYS373 includes a spring-type strain relief to minimize the hard bend a cable has when hanging off the back of a component (which is the point where most cables fail). Two sizes are included for large- and small-diameter cable.

By the way, remember this entry from the “Hall of Shame” that sold for $16 a pair?



Courtesy of Take Five Audio


That’s right, folks, it’s merely a rebadged Neutrik NYS373, but with the price more than tripled! If they can get away with selling them for $8 each, that should give you an idea of just how good this connector is. And what a bargain it is at $2.

My second favorite RCA, and the one I used for many years until I discovered the Neutrik, is the Dayton Super RCA, also sold by Parts Express. As the picture below shows, it's a well-made connector, and it’s also very reasonably priced at under $3 each.


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Dayton Super RCA


The main thing I don’t like about the Super is that it’s one of those bulky-barreled RCAs. However, the barrel is long, which means there is plenty of room “under the hood,” which makes soldering a breeze. Something to watch out for, the internal nylon bushing that the tip sits in is a bit more susceptible to heat than some other connectors I’ve used. The best way to avoid making the tip sag or misalign during soldering is to plug the connector into an RCA coupler.

The Super RCA has a set screw for cable clamping instead of the standard crimped clamp, which I think is a mixed bag. On one hand, it doesn’t secure the cable nearly as well as Neutrik's chuck, but it makes recycling connectors a breeze compared to regular RCAs, since you don’t have to pry the clamp apart. Another downside to the set screw, if you’re using low-profile wire the set screw will fall out of the chassis before it “bites” the cable. All things considered though, I prefer a set screw to an arm/clamp assembly.

Another practical feature of the Super RCA is that it comes with a couple of size options for cable entrance, 6.3 mm and 8.3 mm. This is a picture of the larger 8.3 mm opening.


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The 8.3 mm opening is a sufficient diameter to fit two thin Canare L-2E5 cables, if you wanted to make a “y” splitter cable. This is the preferred method for making a “y” connection: splitting at a connector. Many custom cable makers merely splice three short cable lengths together and cover the mess in heat shrink – totally bogus, in my opinion.

Now that we have our cable and connectors lined out, let’s get our tools together!


Please direct any comments and questions to this DIY cable discussion thread.
 
#6 · (Edited)
Part 3: Assembling the Necessary Tools and Supplies


As with any worthwhile project, proper tools make the difference between things being a struggle or going smooth and easy. Here is a run-down of what you’ll need in order to solder cables. As mentioned before, many of these items are fairly generic and you’ll be able to use them for other projects and purposes; some of them you may already have in your tool box. Any specific brand/part number tools or supplies mentioned are items that I have found work best for their specific task in the process.

Soldering iron
The soldering iron is arguably the most important tool for this job, so I’m reluctant to recommend any bargain-basement options. Weller has been my brand of choice for over 20 years. I used the professional-grade WP35 while I was installing sound systems, and it saw heavy use with no reliability issues except for an occasion tip change. It bit the dust a few years ago, so I’m currently using the “hobbist” WLC100 soldering station, since I no longer require anything professional-grade. I’ve been very impressed with it. The iron itself works as well as the WP35, and you can’t beat the convenience of a built-in stand and cleaning sponge, not to mention the option of reducing the temperature settings for the occasional delicate project. All that for about the same price as the WP35. To let you know what a good deal the WLC100 is for the casual user, Weller’s pro-grade stations start at twice the price.

Another Weller option might be the budget SP40L iron. I haven’t personally used this one, and quite frankly the price is so low it scares me. One thing that does catch my eye is that the SP40L doesn’t have an insulated grip like the other two I mentioned. So it seems to me like the handle could get uncomfortably warm during extended soldering sessions.

Whatever soldering iron you choose, you’ll want it to be between 35-50 watts.

Technology Electronic device Soldering iron

Weller WLC100

Spark plug Auto part Automotive ignition part Automotive engine part

Weller WP35

Tool accessory Tool Auto part Soldering iron

Weller SP40L


Soldering iron tip
Whatever soldering iron you get, plan on changing out the tip that comes with it. The stock tip will be something thick and blunt. Since soldering RCAs and other connectors is close-quarters work, we want a thin, pointed tip to better access the tight places. Weller’s SP7 tip fits the bill perfectly, and can be used with all three of the soldering irons discussed above. The smaller tip retains less heat because it has less mass, which is good for the RCAs. We sure don’t want to ruin them by melting the internal nylon bushings and insulators. Hang on to the original tip, however; it is useful for heavier projects, such as tinning the ends of large-gauge speaker cable. (Unfamiliar terms like “tinning” and others I may use in this section will be fully explained when we start soldering.)

Pen Tool accessory Office supplies Writing implement Ball pen

Weller SP7 Tip


Helping hands
In order to solder a connector, it needs to be stationary. Otherwise it’s rolling around all over the place, and we sure don’t want that. I was fortunate enough to pick up a so-called laboratory support stand assembly from a research facility I worked at many years ago that was slated for the dumpster, and it has been invaluable. Typically this is a three-piece system comprised of a heavy-duty support stand, clamp holder, and clamp.
As you can see, this is a fairly pricey tool, but if you intend to do a lot of soldering, especially in an installation environment, it will be worth springing for one. The ability to raise the clamp to a height of a foot or more is invaluable for terminating connections at a wall plate, for instance. (Note: Somewhat cheaper versions of these items can be found a site called the Science Company.)

Fortunately, there are more economical options for the casual solderist (is that a real word?). The most common is probably the "helping hands" stands sold by Parts Express and other vendors. The downside to these is that the alligator clip doesn’t open very wide, so you’ll probably end up grabbing only the tip of an RCA plug. Fortunately that will be sufficient. The helping hands will also work fine for 1/4” plugs, but not so well for female XLRs. You’ll have to come up with something else for them.

An alternative even cheaper than the helping hands, at least for RCAs and 1/4” plugs, is a plain old clothes pin.

Trophy

Helping Hands

Tool

Homemade Helper


Soldering Stand w/ Cleaning Sponge
If you don’t get a soldering station, do yourself a favor and pick up a combination stand/cleaning sponge. Sure, you can get away with laying the soldering iron on the table when you’re not using it, but sooner or later it’s going to roll or fall off and burn something - or you. A common kitchen sponge, cut to size, can be used in place of a specific soldering sponge.

Stamp seal Food Cuisine

Soldering Stand w/ Cleaning Sponge


Solder
Essentially, solder is a metal alloy with a low melting point, typically in the 3-400° range for the kind we’re using. The type of solder most commonly used for our application is a 60/40, tin/lead alloy. My favorite solder is an ultra-thin .031” type like Kester 44. Unfortunately, Kester seems to be available in nothing less than a 1 lb. spool - which probably amounts to a lifetime supply for the hobbyist. As a more reasonable alternative, smaller spools of .31” 60/40 solder can be found at a variety of on-line venders.

There are at least a couple good reasons for using thin .031” solder over a thicker .050” or .060”. For one thing - as you’ll see when you actually do some hands-on soldering - with the .031” solder you can easily feed in the exact amount you need. With thicker solder, it’s easy to end up with too much.

In addition, the thinner solder melts faster, and as we mentioned in Part 1, we want to be able to get our soldering iron in and out as quickly as possible to avoid potential damage to the cable or connector. You will occasionally find a use for thicker solder, like maybe for tinning large-gauge speaker wire, but probably not enough to justify buying some. If you feel the need, however, Radio Shack sells small spools for only few bucks.

Wire Product Tin Speaker wire Technology

Kester 44 Rosin Core Solder


RCA to 1/4” Mono Plug Adapter
If you opt for the laboratory support stand w/ clamp, you’ll need a RCA to 1/4” adapter because RCA plugs are too small to fit in the clamp. The adapter may also prove useful if you use the “homemade helper” clothes pin as well. The RCA will plug into the adapter, which in turn is held by the clamp.

Automotive exterior Bumper Auto part Automotive window part

RCA to 1/4” Mono Plug Adapter


Utility Knife
A utility knife will be used to score the circumference of the outer jacket insulating our cable.

Wrench Tool Pipe wrench

Utility Knife


Xcelite 103S 5-1/4" Wire Stripper
The Xcelite 103S stripper is ideal for the ultra-thin-gauge wire you’ll find inside a Canare, Belden or Mogami cable. It features an adjustable stop-wheel, which works great for stripping the insulation without cutting into the wire itself and losing some of the individual strands. That’s the last thing you want with thin, stranded wire; there’s precious little to spare. With a little practice you can get used to stripping the wire by “feel” alone and won’t need to fool with the wheel at all. Although this stripper is primarily designed for smaller-gauge wire, I use it for just about every wire I strip, from phone wire to Romex to large-gauge speaker wire. It’s easier and faster than using one of those strippers with the different-sized holes. Behind the stripping jaw, the Xcelite 103S’ edges are sharp enough to cut wire or cable, but you should use them only for cutting small-gauge wire; cutting anything large diameter can distort the entire jaw, rendering it useless for stripping. It’s best to use a specific tool for cutting wire and cable.

Cutting tool Wire stripper Diagonal pliers Tool Bolt cutter

Xcelite 103S Wire Stripper


Xcelite 170M 5" Shearcutters
The Xcelite 170M will be used for cutting away the filler materials you find in a cable once the insulator is stripped back. While the 170M will do some wire cutting, IMO its preferable to avoid that, as even a soft metal like copper will dull the cutting edges and make it useless for cutting the filler materials. The 170M is about the only angled-jaw cutter I’ve been able to find with completely flush cutting edges. That allows you to trim out as much of those filler materials as possible. As a side bonus, the 170M also ideal for flush-cutting the ends off of zip ties.

Diagonal pliers Pliers Nipper Lineman's pliers Wire stripper

Finger Hand Thumb

Xcelite 170M cutters w/ flush-cutting jaw


Xcelite R3322 Miniature Screwdriver
A screwdriver like the Xcelite R3322 will be used for certain kinds of XLR connectors, most notably the Switchcraft brand, but possibly others as well. Alternately, you can use a jeweler’s screwdriver, but they have very thin handles. If a screw is jammed tight you won’t be able to get enough torque on it to break it loose. You’ll be able to with the Xcelite screwdriver.

Green Tool accessory

Xcelite R3322 Miniature Screwdriver



Needle-Pointed Tool
A sharp-pointed tool is most likely something you’ll have to make. It’s best to start with a small jeweler’s screw driver and grind or file the tip to a sharp point. This little gizmo will be used to unravel braided shields, especially the ultra-tight Canare shield. A bit low-brow perhaps, but I’ve found nothing better for the job.

Tool Metal

Needle-Pointed Tool


6” Slip Joint Pliers
Common slip joint pliers will be used for closing an RCA’s cable clamp, if you use that type of connector. Truth be told, just about any kind of pliers can be used, but the slip-joint type has a circular jaw to apply a more even pressure to the circumference of the clamp, rather than just two sides of it.

Diagonal pliers Pliers Line Slip joint pliers Tool

6” Slip Joint Pliers


6” Needle Nose Pliers
A small pair of needle nose pliers will primarily be used if you ever want to recycle RCAs with a cable clamp. Once you pry the clamp off the cable you’ll find it will be distorted. The needle nose pliers can help re-shape it to something resembling its original round shape.

Diagonal pliers Pliers Lineman's pliers Wire stripper Cutting tool

6” Needle Nose Pliers


8” Side Cutters
A pair of fairly substantial side cutters, or some other variety of suitable cutters, be used for cutting our cable stock to length. As mentioned, the Xcelite cutters we’re using are not up to the task of cutting anything with a large diameter.

Diagonal pliers Red Pliers Slip joint pliers Needle-nose pliers

8” Side Cutters


Next up: Now that we have our tools lined out, it's time to do some soldering!


Please direct any comments and questions to this DIY cable discussion thread.
 
#7 ·
Part 4: Soldering RCA Plugs


Okay. You have your tools lined out, soldering iron on and heating, and sponge wetted. You’re ready to go.

For this illustration, we’ll be using the Canare braided-shield cable, since it is the most difficult to prep. Get this one down, and you’ll find most others easy to deal with. Likewise, we’ll start with RCA plugs. Once you master them, most other connectors (like XLR or 1/4”) will be comparatively easy.

After you have cut your cables to the length you want, the first thing to do is slip the RCA’s barrel on the cable. If you’re using the Neutrik RCA, install the chuck clamp as well, with the tapered end facing the barrel.

Hand Finger Cable Thumb Nail


Finger Hand Nail Eyebrow Thumb


One of the keys to a successful project is to properly prepare the cable specifically for the connector you’re using. As you can see from the “under the hood” pictures of the various RCAs we showed you in Part 2, different connectors have physically different distances between the tip and sleeve connection points (i.e. solder cup and clamp/arm). Thus, the first step in prep’ing the cable is to determine how far the outer jacket needs to be stripped back. This is best done by measuring the distance between the cable clamp and the solder cup. (Actually, it’s good for the center conductor to be a smidgen longer than it needs to be – see the "Odds and ends" section further down the page.)

Optoelectronics Technology Electronic device Brass Sensor


With the Neutrik connector, you’ll measure the length between the solder cup and the end of the arm.

Technology Optoelectronics Electronic device Circuit component Electronic component


A full-framed connector like the Daytona Super RCA has plenty of room under the barrel, so much so that it isn’t necessary to strip the jacket back the full distance between the solder cup and clamp. It doesn’t really matter from a functional stand point, but if you’re using Canare cable you certainly don’t want to deal with any more of that brutal shield than you have to!

Electronic component Technology Cylinder Electronic device Optoelectronics


An easy way to measure the length you need to strip is to lay the cable end beside the RCA and mark the place you want to strip the jacket with the utility knife.

Pliers Hand Tool Rotary tool


Once you know where you want to strip the jacket, score the cable’s circumference with the utility knife. This is best accomplished by rolling the cable 360° over the blade with your thumb, applying a little pressure.

Hand Finger Nail Thumb


Next take the Xcelite 103S wire stripper and position the jaw between the score and the cable end. Grip the cable and pull the scored insulator end off. As the picture below shows, you’ll probably find it helpful to push the strippers with your thumb while the other hand pulls. (NOTE: If the jacket doesn’t want to come off, it’s probably because it was not scored deep enough. With your next attempt, apply a bit more pressure when you roll the cable over the utility knife.)

Hand Finger Nail Thumb Fashion accessory


Finger Hand Thumb Office supplies


Now take the pointed jeweler’s screw driver and completely unravel the braided shield. (If you’re using a cable with a spiral shield, the shield will easily unwrap – no pointed tool needed.)

Nail Finger Eyebrow Skin Hand


Brush Toothbrush Finger Hand Nail



Afterwards, fold the unwrapped shield down away from the filler material.

Finger Hand Thumb Nail


Next, spread out the strands of filler material.

Finger Hand Technology Cable Thumb
 
#8 ·
Cut away the filler material using the Xcelite 170M shearcutters, as flush with the pulled-down shield as you can get it. The idea is to get rid of as much of the filler material as possible.

Hand Finger Leaf Insect Plant


Cable Wire Finger Technology Electronic device


Now pull the strands of shielding to one side.

Finger Wire Hand Thumb Thread


Twist the shields strands together, then proceed to strip the insulation off the ends of the center conductors using the 103S strippers. Try to make sure both are stripped to the same length.

Finger Hand Thumb Nail Pliers


Finger Cable Wire Hand Technology


This is where it gets tricky. The jaws of the 103S strippers are very sharp and can easily cut right through the center conductor. If you’re unfamiliar with them, it’s best to set the stop wheel for the depth you want to cut – which would be just enough to cut through the insulator but not the strands of wire underneath. It might be a good idea to practice with a scrap piece of cable to get the right stop depth lined out, or maybe get a small spool of #22 or #24-gauge hook-up wire from Radio Shack to practice on. The center conductors are very thin and we don’t want to bite into them and thin out the strand count, if at all possible. That said, it’s not the end of the world if you do lose some strands. After you use the 103S strippers for a while you will get a feel for when you’ve cut through the insulator and reached the wire underneath, and you won’t need to use the stop wheel anymore. But until then - use it!

Next, twist the two center conductors together.

Finger Hand Thumb Office supplies

This is the prep for the “best durability” configuration, where the cable would still work in the event that one conductor failed.

If you want to go with the “best noise rejection” configuration, the prep is a little different. With this configuration you would not strip both center conductors’ insulation the same length, as shown and described above. Instead, one of the center conductors will be stripped as close to the shield as possible.

Finger Hand Thumb Nail


Finger Hand Thumb Plant


Bend the flush-stripped conductor’s wire strands over into those of the shield.

Finger Cable Hand Wire Technology


Then, twist the center conductor wire strands into those of the shield (note the presence of both copper and silver stands in the shield in the picture below). This will send the signal (-), which normally travels on the shield, through one of the center conductors, which are twisted internally through the length of the cable. According to theory, when the signal (+) and (-) constantly change positions 180°, it aids in noise rejection. (The astute reader will no doubt note that the (-) signal will at this point be riding on both the second conductor and the shield. This situation will be addressed later in the Odds and Ends section – stay tuned.)

Wire Finger Cable Hand Technology
 
#9 ·
With our cable prep’d, now we can solder it to the connector.

Please keep this in mind as we proceed: Any time you pick up the soldering iron to use it, or return it to the stand after using it, the tip it should be cleaned by wiping it across the wet sponge, fore to aft.

Hand Measuring instrument Technology Tool Electronic device


Cleaning before each use rids the tip of oxidation that builds up on its surface, which accumulates rather rapidly because of the extreme temperature. Cleaning afterwards purges the tip of solder and rosin residue. The rosin is especially problematic because once burned it becomes a corrosive agent that will eventually eat away at the tip and ruin it. Do this (i.e. soldering) long enough and you’ll eventually see a tip with a chunk missing from it, like someone took a bite out of it. That’s what latent rosin residue will do.

The first step in the soldering process is known as “tinning.” Tinning is basically a “pre-loading” that infuses the stranded wire with solder. Any pieces that are to be soldered together must be tinned beforehand. This of course means that the RCA connector will need to be tinned as well as the wire. When you go to solder the wire to the connector, solder will melt and flow (exchange) between the two. The result is a connection that is both physically and electrically sound.

Before tinning the cable or connector, first tin the iron by adding a dab of solder to it. Due to the necessary and frequent cleaning of the iron, it will need to be freshly tinned each step of the way. Basically, you should get in the habit of tinning the iron any time you pick it up, just as you should make it a habit to clean the tip. So to be perfectly clear, the proper procedure is: (1) pick up the iron, (2) clean the tip, (3) tin the tip, (4) tin the wires or connector (or perform the soldered connection), (5) clean the tip, (6) return the iron to the stand.

You will notice some smoke when you tin the iron. This is from the rosin in the solder burning. It’s not healthy to breathe that smoke, so make sure you’re working in a well-ventilated area.

Hand Finger Cable Metal Soldering iron


In practice I like to tin the cable first, then the connector, because it requires less shuffling of pieces in and out of the helping hands clamps. However, for the sake of written continuity in these instructions, we will start with the RCA connector.

Press the (cleaned and) tinned tip of the soldering iron into the solder cup for 2-3 seconds, then add solder. When the solder cup reaches the right temperature the solder will melt and flow into it. Feed in enough solder to fill the cup.

Hand Tool


Metal Brass


Next press the tip of the iron to arm, slightly behind the solder cup. Heat and add solder. This picture of the Neutrik connector shows what your tinned locations should look like. As you can see, there is a small pad of solder on the arm, and the cup has a good amount of solder filling it. Any more than this is excess, which is not good.

Brass Auto part Metal


If you’re using a standard RCA, the arrow in this picture shows the correct location for the solder pad on the arm/clamp assembly.

Optoelectronics Technology Electronic device Brass Circuit component


The next step is to tin the bare ends on our prep’d cable - i.e. center conductor and shield. We’ll start with the center conductor.

Press the iron to the bare wire and immediately add a bit of solder to the wire. When the wire reaches the correct temperature, the solder will melt and flow into the wire. When that happens, pull the iron away. The whole process should take only 2-3 seconds (unless you’re using an iron with lower wattage than the 35-50 watts I recommended in Part 3 – if you are, it will take a bit longer). Leave the iron in place too long and the center conductor’s insulator may start to melt.

Hand Rotary tool Finger


Hand Rotary tool Finger Soldering iron Metal


Wire Cable Technology Electronic device Finger


The wire should be fully saturated with solder, but not to the point where it is “globbed” like this:

Helicopter Rotorcraft Helicopter rotor Aircraft Vehicle


Here is what a “before and after” should look like. Basically, if the wire looks pretty much the same as it did before, but you can see that the color has changed from copper to silver, you’ve done it right. :T

Product Text Water Line Font

Before tinning


Cable Wire Technology Electronic device Coaxial cable

After tinning
 
#10 ·
To tin the shield, start towards the end: Press the iron to the wire, add solder. The shield is thicker, so it will take a bit longer for it to heat up and for the solder to flow into the wire. But not much longer – only another second or two at most (compared to the time it took to do the center conductor).

Hand Finger Cable Metal


When the solder starts flowing into the shield, move the iron towards the cable and keep feeding in solder as you go. Pull the iron away as the solder saturation reaches the cable. This is very important! Keep in mind that the shield has a lot more mass than the center conductor, and as such can retain a lot of thermal energy. If you hold the iron in place too long near the center conductor, the shield can be heated to the point that it melts through the center conductor’s insulator and causes a dead short between the two. You won’t be able to see this because it’s happened inside, underneath the cable’s jacket, but when you finish your cable and plug it in you’ll be wondering why it doesn’t work. Fortunately, you have to try pretty hard to screw up like this, like holding the iron in place several seconds or longer.

Here are a couple of “before and after” pictures of the shield. As you can tell, with the right amount of solder added you should be able to see the texture of the wire. If it looks like a smooth, shiny “finger,” then you put in too much solder. For these pictures I switched to a cable with a copper shield, to better see after-the-fact solder saturation. Note that the saturation stops just before the jacket, although it’s acceptable to take it all the way up to the jacket (just move the iron away immediately when it gets there).

Cable Wire Electronics accessory Electronic device Speaker wire

Before tinning


Cable Wire Electronic device Technology Electronics accessory

After tinning

You will notice in the pictures shown here that there are two ways of contacting the wire with the soldering iron: Parallel to the wire, or perpendicular. Parallel contact will naturally transfer more heat to the wire, and faster, compared to perpendicular, due to a greater contact area. You can try either way to see which suits you. (If you are heating something large-gauge, like if tinning the ends of speaker wire, parallel contact would probably be the method of choice.)

After tinning the prep’d cable, trim the shield to a short length with the Xcelite 170M shearcutters. It should be only be long enough to reach the pad of solder on the clamp arm of the RCA; no extra length is needed. If the tinned center conductor is too long (as it probably is in the picture below) it may be trimmed some as well. If it’s too long it’ll be hanging out way beyond the solder cup, which is poor technique.

Cable Coaxial cable Technology Electronic device Wire


Now we are ready to solder the cable to the connector. Clean and tin the tip of the iron with a dab of solder, lay the center conductor on the pad of solder in the solder cup and press the tip into the wire and cup. After a few seconds the solder cup will reach the correct temperature, the solder will melt and the center conductor will drop into the pool of solder. When that happens, pull the iron away and hold the everything still.

Make sure the solder joint is not disturbed or moved until the molten solder solidifies. Otherwise you will get what’s known as a “cold joint,” which will fail almost immediately. A successful weld will have a shiny appearance; a cold joint will look like flat silver spray paint. If your solder connections looks like the latter, do it over by tinning the iron and pressing it into the connection. When the solder melts pull the iron away and hold everything still.

Hand Finger Nail


Cable Wire Coaxial cable Technology Electrical wiring


(Note: Even though there is obviously ample solder present in the solder cup, the iron should be still tinned before trying to fix a cold-joint goof. This provides a fresh infusion of rosin that will help the solder melt quickly. You’ll notice that not tinning the iron first results in a much longer time for the solder in the cup to melt. Naturally, this means potential damage to the connector.)

Next we’re going to do the same thing with the shield. Clean and tin the iron with a dab of solder, this time using a bit more than you did with the center conductor. Press the shield to the pad of solder on the connector’s arm, and press the iron there as well. When everything reaches the correct temperature, the shield will drop into the pad, and solder will melt and flow between the two. When that happens pull the tip away and hold the cable still until the solder solidifies. Leave the iron in place too long and the solder will spread out all over the clamp arm. Doesn’t really hurt anything, but it isn’t doing anything useful except where the shield makes contact.

Hand Finger Rotary tool


Cable Hand Finger Pipe Coaxial cable


Here’s what the finished product should look like with the Neutrik connector.

Cable Technology Electronic device Coaxial cable Electronics accessory


Here’s what the finished product should look like if you’re using a standard RCA. Be sure and use your pliers to crimp the clamp around the cable. (By the way, I didn’t do this one myself, I found it on a job site. But I must say it’s a simply beautiful example, absolutely perfect.)

Cable Brass Electronic device Coaxial cable Metal


Were basically done ! If you’re using the Neutrik RCA, slide the chuck up over the connection. For regular RCAs with an arm / clamp assembly, use your slip-joint pliers to crimp the clamp tightly to the cable.

Hand Finger Cable Wire Tool


Screw on the barrel and pat yourself on the back for successfully completing your first DIY connection!

Cable Hand Finger Wire




Thanks to Donna Pflughaupt for taking most of the photos in Posts #7 - #10.
 
#11 ·
Wrapping up a few odds and ends


Finishing up “best noise reduction” cables
If you’re doing the “best noise rejection” method where one of the center conductors is tied into the shield: When you make up the other end of your cable, the conductor that you tied into the shield will be soldered to the RCA’s sleeve (i.e. clamp arm). To clarify, the shield will be connected to one end of the cable only. This will send the signal (-) solely through the center conductor.

Have you seen those “tweak” DIY cables where they eschew shielded cable for singular wires twisted together either by hand or in an electric drill motor? In lieu of a shield, the twisted center conductors are supposed to accomplish the noise rejection. It works pretty well in most situations, but there’s no substitute for a good shield. Well, our “best noise rejection” method will allow you to accomplish the same twisted wiring as those “tweak” cables, since the dual center conductors are internally twisted down the length of the cable, while maintaining the shield. Win win.

The picture below shows what the prep’d cable will look like – the blue conductor will go to the tip connection (solder cup), the white one goes to the sleeve (arm assembly).

Cable Wire Electronic device Technology Electronics accessory


Please note, it’s impossible to completely clip off the strands of the shield. That’s a problem, because if any part of the shield makes contact with the connector, then the (-) signal will be sent through the shield as well as the white conductor. Personally I’m not sure if that matters or not (I usually tie the second center conductor to the shield on both ends), but if you want to make sure the signal (-) is traveling only on the center conductor, then the shield cannot make contact with the connector on this end of the cable.

As you can see in the picture above, there is no shield visible at all. This is what we want. This can be accomplished by first shearing the shield as close as possible with the Xcelite 170M cutters, then stretching the jacket of the cable over whatever shield is left. This is done by gripping the cable a few feet back from the end with one hand, and with the other hand stroking the outer jacket from that point down to the end of the cable. The end result is the jacket is stretched and pulled down over the shield, covering and fully isolating it from the connector, as the picture shows.

Also note - in my opinion this does not matter, but some believe that the end with the shield connected to the RCA should be used only on the source side, not destination side (e.g. the pre amp, not the amplifier).


What about cable beautification?
Some people like to pretty-up their cables with techflex and heat shrink, like Otto did in the picture below. Looks cool as all get-out for sure, but personally I don’t get it. No one’s going to see it behind your equipment rack, and it only jacks up the cost and make-up time. But feel free if it floats your boat. The techflex and heat shrink would be added after the fact.


Cable Electronics accessory Wire Electronic device Technology

Courtesy of Otto


The heat shrink serves at least a couple of purposes, to secure the techflex in place, and to act as a strain relief, much as the spring does with the Neutrik and Radio Shack Gold connector. However, I’ve seen in my former cable-repairing career that if there is a cable failure due to breakage of the center conductors, it will be just past the end of the heat shrink, since that becomes the “hinge” where the cable is bent and flexed. So basically, the heat shrink just moves the potential breakage point downstream, as it were. In my opinion spring strain reliefs are better because they “soften” the bend by giving it a wider radius.

Another method to utilize the heat shrink is to send it under the barrel, instead of on top, as Owen Bartley did here.


Cable Technology Electronic device Metal Coaxial cable

Cable Coaxial cable Technology Electronic device Electrical connector

Courtesy of Owen Bartley


Making “Y” cables
In Part 2 where we discussed the best RCA connectors (Post #5), I mentioned that the preferred technique to accomplish a “Y” split is at the RCA connector, not by splicing three loose cable ends together, which is what many custom cable makers do. You can make a “Y” cable by using a Dayton Super RCA connector with the enlarged 8.3 mm opening in the barrel and a low profile cable like the Canare L-2E5. The two cable ends to be spliced would be prep’d as described in Post #7, but with the center conductors and shields of both cables twisted together - before tinning. Here are a couple of pictures of the finished product.


Metal Cable


Product Technology Electronic device


Actually, the center conductors should have been pushed into the solder cup a little further than shown here, so this isn’t exactly my best work.


Stress issues
Notice in the pictures above that the center conductors are a bit slack – i.e. not stretched tightly between the end of the cable and the solder cup. This is done intentionally for the purpose of increased durability. The premise is based on the fact that the center conductor is fairly fragile compared to the much-thicker and more-substantial shield. In the event that the cable ever gets yanked or subjected to similar abuse, the shield will be what takes the brunt of the punishment, not the center conductor. Thus, the cable will sustain the abuse and not fail.


The hall of shame
Now that you’re a highly trained soldering expert, you’re sure to be amused by this stunning example of “what not to do” that I came across a few years ago on another Forum – see the next three pictures.

Frankly I’d be too embarrassed to post these pictures on the Internet if this was my work. This poor fellow shows every classic soldering mistake that there ever was. This is an example of everything done wrong from start to finish.

Right off the bat we can see our amateur chose a cable that’s too large for the connector, which is a 3.5 mm mini headphone plug (formerly know as a 1/8” stereo plug). Notice, there’s no way the cable clamp will ever fit around that cable. The cable has four conductors, which is totally unnecessary as only three are needed for this application, a headphone extension cable. A simple two-conductor low profile mic cable like the Canare L-2E5 would have done the job (with the shield functioning as the third conductor).


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You can see in the first picture that he inserted the stripped wire ends into the holes in the terminal arms and looped them back. He thinks this will make the connection more secure. We’ll get to that in a minute, but the main problem is that he did not tin the wire!

Never, never, solder wires to a connector without first tinning them! And the connector! If you don’t, when you go to solder, the wire will never get hot enough for the solder to flow into it – and some of these pictures show that’s exactly what happened. The reason is that the point of termination to the connector (i.e. where the wire will be soldered – tip, sleeve, solder cup, etc.) needs to absorb heat too, in order for the solder to adhere to it (since it also wasn’t tinned before hand), and therefore “siphons” off heat from the wire. Sure, you could leave the iron on long enough for solder to flow into the wire properly, but that will result in the terminal getting so hot it’ll melt the plastic or nylon inserts in the connector. In other words, the connector will be ruined. It will also most likely ruin the wire as well, melting the insulation.

The result of this poor soldering technique is that the wire never gets fully infused with solder. You have no way of knowing if the solder actually penetrated into the wire or if it’s merely sitting on top of the wire’s circumference. This connection may be electrically viable but it is not physically robust, as would be if everything had been properly tinned first.




Plus, as we’ve shown, you only need enough solder to fuse the tinned wire and connector together – no more, no less. “Blobbing” on excess solder like you see here doesn’t result in any advantage or improvement in the electrical or physical connection. Indeed, it can result in a short circuit when you screw the barrel onto the connector.

So, what about inserting your wires – tinned or not – into and through the connector terminal’s holes and bending them back, like you see here? Will this make the connection more secure from stress or abuse? In a word, no. You might think it would make the individual wires more resistant to breaking, but such is not the case. The reality is that once the wire is tinned, it becomes much stronger than it was before. In the event of stress or abuse, the wire will not break or break loose at the point of termination. It can’t, because it’s effectively welded to the connector. What’s going to happen is that the wire will break a little further down, where it is not tinned. That’s right, the solder connection will remain intact; the untinned wire downstream is the weak link. Believe me, I’ve seen every kind of damage a cable and/or connector can sustain while I was repairing those countless dozens of cables from shows and concerts. Trust me, you will never - never! - see the cable fail at the point of the soldered connection! (Unless it was a cold joint to begin with.) The most common failure in cables that are abused or simply handled a lot is the center conductor(s) breaking just past the barrel of the connector, because this is the “hinge” point where the cable gets bent, twisted and flexed a lot.


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In addition, looping the wire through the holes in a connection terminal like this increases your chances for a short circuit, especially in the small, close-quarters connectors we use in home audio. It’ll happen when the barrel is screwed on – i.e. the short will occur between the barrel, which has continuity with the sleeve connection (i.e. signal [-]), and the wire protruding profusely from the hole-through terminal (signal [+]).

Sure, many connectors, especially 3.5 mm and 1/4”, have a protective cardboard or plastic sleeve inside the barrel to prevent this. But notice in the pictures how the termination arms are spread far wider than the connector itself. See those threads on the connector? That’s as wide as everything is going to be when the barrel is screwed on. When the barrel is screwed on it’s going to squeeze everything together, and that could very well cause a short as one terminal bends and makes connection with another – or rather with the blob of solder on another.

I’ll give this guy credit for even trying to tackle a 3.5 mm head phone plug, which is one of the more difficult and tedious connectors to solder. With most of them, there isn’t much room “under the hood” so the tolerances are really tight.

If you need to make a 3.5 mm cable, either mono or stereo, Canare’s F11 (mono) and F12 (stereo) connectors are hands down the best available and easiest to work with. Canare had the good sense to realize, “Just because the plug itself is small, that doesn’t mean the barrel has to be.” That’s right, the F11 and F12 feature a full-sized barrel with an opening that can even accept the full-sized Canare's L-2T2S cable recommended in Post #2. You can see the difference in barrel sizes in the pictures below of a common and Canare 3.5 plugs.


Electronic device Technology Electronics accessory Cable
Tool accessory Metal



Maintenance issues
As previously mentioned, the best thing you can do to preserve your soldering tip is to clean it each time you put it down, and especially before you turn off the iron at the end of a project. Burned rosin is a corrosive agent, and leaving it on the tip will eventually ruin it.

Even if you do take care to keep the tip cleaned, they don’t last forever. If you notice that the iron is taking a long time to heat up, or never seems to be hot enough, that’s an indicator that it’s probably time to replace the tip. But before you do, check to see if the set screw is tight, if there is one.

Aside from that, it’s a good idea to keep some of the specialty tools, such as the Xcelite 170M shearcutter and 103S wire stripper, designate as “for soldering use only” or perhaps other light-duty uses. This will keep their cutting edges sharp. Especially, don’t use them to cut any solid-core wire heavier than telephone wire. Gauges any heavier (numerically smaller) will very likely gouge the cutting edge.

The 103S strippers have an attached arm that’s designed to keep the handles locked down in the fully-closed position for more compact storage. I suggest, do not use it! I found that storing them with the handles locked down would make the torsion-bar spring break after a couple of years. This might not be the case for the casual user, but it certainly was when I was an installer, using them on a regular basis and locking them down at the end of the day. Once I started storing them with the handle open I have broken no more springs, and I’ve been using my current pair for more than 10 years now. Fortunately, if you do break a spring Xcelite has a free-replacement warranty.



Please direct any comments and questions to this DIY cable discussion thread.
 
#12 ·
Part 5: Soldering XLR and 1/4” connectors

Once you’ve mastered soldering RCA and other home audio connectors, you’ll find the XLRs and 1/4” connectors typically found in pro audio equipment are pretty easy. As with RCAs, the key to a successful project is to properly prepare the cable for the connector you’re using. Once that is done, soldering to the connector is a piece of cake.

I won’t go into the full detail of stripping, prepping and tinning the cable here – refer to Post #7 for that.

First up we’ll look at 1/4” connectors. These come in two varieties, TS (tip/sleeve) and TRS (tip/ring/sleeve). These are also commonly called “mono” and “stereo,” respectively.

One of the unfortunate and shortcomings in just about every field of audio has been the chronic practice of utilizing common connectors for multiple applications. For instance, the ubiquitous RCA connector has been used for line level audio, video, coaxial digital signals, and even for speaker connections (no kidding, back in the ’60s). In musical instrument applications, the “mono” or 1/4” TS plug has been used for both low-level electric guitar inputs and high-level speaker connections. The “stereo” or 1/4” TRS plug has been used both in home audio for headphone plugs, and in professional audio for balanced signal connections.

As you can imagine, this has been a constant source of confusion, as each of the abovementioned applications require a specific and appropriate cable, even if they share the same plug or connector. The main thing to keep in mind is that any cable used for line or mic-level signals must be shielded, and that mic or signal cable is light-duty and should not be used for connections between an amplifier and speaker.


TS/mono 1/4" connectors
The cable for a 1/4" TS connector is prep’d much the same way as a RCA, except that the shield is typically longer. The picture below shows both center conductors of a mic cable tied together. Naturally, one of conductors can be tied into the shield, as outlined in Post #8.


Finger Hand Cable Pen Rotary tool


Here’s what the finished connector should look like after soldering. Note that the cable’s outer jacket is far enough forward to be gripped by the cable clamp. Also notice that the center conductors are not stretched tight. I leave them a bit long when prep’ing the cable, so as to give them some slack. The idea is that the shield is much more robust than the center conductors, which are thin and relatively fragile. In the event that the cable ever gets yanked or is subjected to similar abuse, the shield will be what takes the brunt of the punishment, and the cable will not fail.


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After soldering, use your pliers to secure the cable clamp, screw on the connector barrel, and you’re done.



TRS/stereo 1/4" connectors
Soldering 1/4" TRS connectors is a bit trickier, but not much. With a TRS cable you’ll be using both center conductors – i.e., you won’t tie them together.

My favorite 1/4" TRS connector is the Switchcraft #297. It’s an excellent plug with a superb build quality, but in stock form it’s a bit cumbersome for soldering. With the barrel removed you can see that one of the tabs sticks out at a weird angle, and there is a plastic protector covering the arm (shield connection) that’s basically just in the way.


Hand Bicycle part Metal


So I’ve always modified the 297 a bit. The first thing I do is clip off the angled tab with my 8” side cutters.


Hand Finger Writing instrument accessory Writing Thumb


Technology Finger Metal Cable


The next thing we want to do is get rid of the useless shield protector. We’ll clip this with our Xcelite 170M cutters.


Finger Hand Thumb Pliers


Brass Finger Cable Metal


After the connector is prep’d it can be tinned. Tin the inside of the two tabs, as that’s where we’ll be soldering the wires. The arm will be tinned for the shield just behind the clipped-off protector.


Zipper Fashion accessory Metal


Once the connector is prep’d, we can move on to prepare our cable. The center conductors need to be long enough to spread between the two tabs on the connector. Better to have the center conductors a bit too long with some slack than too tight. Here’s what the prep’d and tinned cable end will look like (with the center conductors perhaps a bit longer than this). The shield lead will be shorter than the center conductors.


Cable Wire Electronics accessory Electronic device Technology


You’ll probably want your connections to follow accepted signal (+) and (-) protocol, for both cable and connector. For cables, the red conductor will usually be signal (+), and black will be signal (-) (as an example – there is no industry standard for mic cable center conductor colors). For the connector, the tip is signal (+) and the ring is signal (-). If you’re unsure which tab is tip or ring, use an ohm meter to check continuity.


Text Diagram Technical drawing Parallel


Here’s what the connector will look like after soldering. I got this example a bit “tight.” More length on the center conductors is acceptable as long as the cable’s jacket can be fully secured in the cable clamp.


Technology Pipe Auto part Electronic device Cable


By the way, any good 1/4" connector will include a cardboard or plastic sleeve under the barrel that slips over the connections. Do not forget to use it!!!



XLR connectors
We've previously discussed the importance of using good connectors, but this is especially critical with female XLRs . A lot of people make the mistake of buying cheap female XLRs not realizing that they are total junk, living on borrowed time. Take a look at this picture that compares a cheap and quality connector:




The bottom connector is a Switchcraft, the top is a no-name something-or-another. See the little ball at the business end of Switchcraft? The Switchcraft has two of those, and they are spring loaded. The purpose they serve is to maintain a tight pressure connection in the socket they are plugged into.

Now look at the cheap connector. It has no spring loaded balls. All it has is a couple of "bulging tabs" to ensure a good connection (for lack of a better term - one of them seen here circled in green, between the two dark strips). The problem is that over time, the tabs will collapse, and you end up with a goose-loose connection that has a lot of flex and give. That in turn wallows out the plug's three sockets, which then can easily make and break connection. So basically, the whole mechanical structure of the connector is compromised.

So, don’t waste your time with cheap female XLRs. Use only a brand name like Switchcraft or Neutrik. (Note that the Neutrik connectors don’t use a bulging tab or a spring-loaded ball to physically secure the connection. Don’t let that deter you, they’re excellent connectors.)

As it is with any type of connector, the key to a successful XLR cable project is prep’ing the cable. Typically the pinout for audio XLRs will be Pin 1 = shield; Pin 2 = signal (+); Pin 3 = signal (-). However, older pro audio gear made before the 1990s may be Pin 3 = (+), so know what your equipment requires before you make your cables. Combining old and new gear can end up with one of them having the signal polarity wrong on one end (NOTE: This applies to 1/4" TRS connectors as well).

Unlike the other connectors we’ve looked at, the shield for XLRs will be the same length as the center conductors.


Logo Auto part Emblem


Keep in mind when prep’ing your cable that it should be correctly oriented for the connector’s gender. Since XLRs pins are arranged in a circle and the male and female connections mate to each other, their pin arrangements are different. One is arranged (clockwise) 2-3-1, and the other is 1-3-2. Cable orientation makes a difference when prep’ing the cable. For instance, the cable’s red center conductor will typically go to Pin 2 (+), and the black conductor to Pin 3 (-) (again, this is “for example” – there is no industry standard for the colors). With the correct orientation, once the cable is prep’d the red conductor will fall naturally to Pin 2, and the black to Pin 3. If you have to twist the conductors across each other to reach the correct pin, you have the orientation wrong. Nothing to worry about, just solder that end to the other XLR – e.g. male instead of female.

When tinning a male XLR, the solder cup will need to be fully filled with solder. In the picture below the left-side cup has been tinned; the right side has not.


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Here’s what the finished connection will look like.


Cable Coaxial cable Technology Electronic device Electronics accessory


During soldering, the easiest way to deal with a male XLR is to plug it into a female XLR. The female XLR can then be easily held in place by your “helping hands” apparatus (see Part 3).


Fuel line Cable Auto part Pipe



Unbalanced XLR concerns
In a home audio system using both consumer and professional equipment, often the front end (pre amp) will have RCA connections, which is an unbalanced output. If you’re using a downstream pro audio processor, often they will have XLR connections only. So (naturally) you’ll need cables with RCAs on one end and XLRs on the other. Unlike balanced connections, the unbalanced signal sent from a pre amp via RCAs technically needs only two connections to operate. But as you’ve noticed, XLRs have three connections.

As previously mentioned, the pinout for balanced audio XLRs is Pin 1 = shield; Pin 2 = signal (+); Pin 3 = signal (-). However, with unbalanced audio signals the signal (-) is carried on the cable’s shield. So when making a cable with RCAs on one end and an XLR on the other, the shield should connect to Pin 3, with a jumper added between Pins 3 and 1. If there is ground-loop noise in the system, often it can be alleviated by not installing the jumper.

You would have a similar connection with an RCA to 1/4" TRS cable, with the latter’s tip carrying the signal (+) and the ring carrying (-), and a jumper between the ring and the sleeve (i.e. the arm where the shield is normally soldered). However, with the possible purpose of eliminating a ground loop, there is no reason to use a RCA/TRS cable. The same connection can be functionally achieved with a RCA/TS cable.



Please direct any comments and questions to this DIY cable discussion thread.
 
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