DIY Silver Interconnects

The Marketing Hype:

While assembling my current home theater system, I started to literally trip over product literature extolling the virtues of superior cables to connect your CD player, DVD player, etc. to your amplifier. Almost everything I found started off by commanding the reader to "throw away those cheap, crappy cables that came with your CD player!" Interestingly (and consistently), that is where the good advice always ended. Next, the manufacturer would go on to say how they have invested millions of dollars in high-tech specially designed fabrication processes that use ultra-pure copper arranged in some special and always proprietary configuration and how great of an improvement it will make in your system. Its pretty easy to get sucked up by this marketing hype, but reality hits only several moments later when you dig up the price of these awesome, greatest-thing-since-sliced-bread interconnects: $250 per half meter! HALF METER?!?! Ok, what could possibly be so great about a cable that it costs that much money (lots of people don't spend that much money on their CD player, or maybe even their whole stereo...)? Well, quite frankly, nothing... After all, wire is wire and its job is merely to carry electrons from your CD player to your amplifier, right?

The Reality:

Fast forward a few months. I came across an ad from an online vendor who was heavily discounting a set of Monster M950i interconnects. These cables usually retailed for about $100 per half meter pair and I picked them up for about $40. I figured that I had wasted far more money on things that didn't work, why should this be any different? Besides, many people advocate spending approximately 10% of the value of your system on cables, and since I had spend nearly nothing on cables so far, I figure it was worth a shot. When they arrived, I eagerly hooked them up between my CD player and my amp and was immediately surprised! The skeptic in me could not believe what my ears heard: the sound was so much better! Stronger bass, more clearly presented treble, and an improved sound stage! Wow, these cable were great! Something about these cables was clearly superior to the $0.05 cables that came with my CD player.

The Fun Part:

Many of the more expensive cables are made of superior materials and often do sound better. But here is where it gets interesting: You can build your own set of interconnects that will perform better than most esoteric, snake-oil brand cables and cost far, far less. Interested? Read on!

I did some reading on AudioAsylum (in the cable forum) and kept coming across references to Chris VenHaus's DIY Silver Interconnects. By all accounts, following Chris' instructions would yield a set of interconnect that would be far superior to many of the expensive and esoteric brands of cables out there, so I figured I would give them a try.

I deviated a little from Chris' instructions. I originally got some 1/4" Teflon tubing to use as the core material for my wires, but it proved to be too rigid. When you bent it more than a certain amount, it kinked and the tubing collapsed - not at all what I wanted. In its place, I used a 1/4" diameter cotton rope from the local hardware store.

Materials:
Silver wire is generally preferred to copper for its greater conductivity rate (99%) when compared to copper (97%). Many people say "but what about using gold?" Gold is well known for its anti-corrosion properties, which is why it is preferred for various electrical connections (for example, gold plated RCA plugs). However, the conductivity of gold is approximately 79%, far below that of copper or silver. It is also many times more expensive than silver. Chris recommends using silver wire that is already Teflon insulated. This works well and is easy to use, but the cost is rather high ($2 per foot, so $50 for a 25 foot spool of 30 gauge wire). Instead, I ordered 2 ounces of 30 gauge .9999 fine silver from Myron Toback, Inc. in New York. Be sure to get FINE silver and not sterling silver. Their minimum order is something like $25, which worked out nicely to 2 ounces of 30 gauge silver wire at the time that I ordered mine (edit - this is when silver prices were closer to $5-7 per ounce). Two ounces results in about 400 feet of 30ga wire! Not bad, considering the alternative costs twice as much for one sixteenth of the length (32x as expensive)... Now the "problem" is that this wire is bare, and thus needs to be insulated. Some may balk at this point claiming that the silver wire will tarnish since it is not insulated, however, silver sulfide is highly conductive - unlike the familiar green copper oxide that forms on copper (Statue of Liberty, anyone?) wire that that is not electrically conductive.

Lengths of Teflon tubing can be purchased from McMasterCarr. Teflon is perhaps the best known insulative material (next to a vacuum). Do a search on "PTFE Spaghetti Tubing". To insulate 30 gauge wire, you need 28 gauge (larger inner diameter than the outer diameter of the wire) inner diameter tubing. The extra diameter is quite handy to thread the wire through the tube. If you purchase it in 100 foot lengths, the cost is about $0.06 per foot. So now you have 400 feet of wire, 200 feet of insulation, and the cost is less than $50 delivered - roughly the same cost as 25 feet of pre-insulated wire from other sources.

You will also need some RCA connectors. Good RCAs feature solid COPPER construction (not gold plated - remember, while gold is resistant to corrosion, it is not terribly conductive) and have Teflon insulation between the center pin and outer barrel of the connector. You can find them at a variety of sources such as Parts Express. I purchased my RCAs from Home Grown Audio for about $4 each, but the ones I ordered are no longer available (it seems they have been abandoned in favor of more expensive models that feature solid silver construction - which might be worth trying, but only if I can find some silver female RCA connectors...). Home Grown also carries a full line of wire and terminals that you may find useful if you get hooked on making your own wires. I certainly would not purchase less expensive RCAs, however, there are plenty that cost more... I would consider anything offered by Home Grown to be of sufficient quality

Since you are using silver wire, it only makes sense to use silver solder. There are two primary camps here, and I am not sure which to pay attention to, but here they are. Silver solder comes in two varieties: eutectic and non-eutectic. Basically, eutectic solder has a single, discrete melting point at which it will instantaneously turn from a solid to a liquid and vice versa. It is composed of a specific ratio of Tin, Lead, and Silver. Examples are "Wonder Solder" and "Cardas Solder" both available from Michael Percy Audio. The advantage of eutectic solder (besides its silver content) is that you get a quick, easy, and solid connection since the solder changes from a liquid to a solid so quickly, leaving behind a mirror-shiny surface. Now, some will say that the lead in the solder joint will cause audible problems (my ears are just not that sensitive...). These people advocate the use of lead-free silver solder (tin, silver). This solder does not have a discrete melting point, so you have to be a little bit more careful and patient while waiting for the solder to "set". The trade-off is yours to make. Either is better than standard tin-lead electronics solder. Under no circumstances should you use solder that is intended for pipe fitting - this is an entirely different animal!

Finally, the easy stuff to find. Go to your local hardware store and get some 1/4" diameter cotton rope and a few spools of regular 3/4" or 1" wide plumbers Teflon tape. Also, see if you can find some light hobby oil that comes in a small container. If you have a model railroad or hobby shop near you, they will most certainly carry it.

Construction:

I basically followed Chris' recipe with a few alterations: used cotton rope instead of 1/4" Teflon tube and bought bare silver and insulated it myself. Threading the silver wire through the Teflon tube is probably the most difficult part of this job. If you don't want to fool with this part, then get silver wire that is already insulated. Its really a time vs. money tradeoff. To get a 24" interconnect, you need to start with about 39" of silver wire and 36" of Teflon tubing. How you cut the wire and the tubing also makes a difference in how easily you can thread the wire. If you use wire cutters or scissors, you will have a hard time. Both will "pinch" the wire and the tubing. Pinching the wire will leave behind a burr on it that will snag as it goes through the tubing and the openings on the tubing itself will be pinched off. Instead, use a sharp exacto razor knife. The knife will make short work of both the wire and the tubing, and will not damage the end of either. Note: If you plan on making interconnects longer than 24" in length, you may need to purchase silver wire that is already insulated. The problem is that the longer your interconnect is, the more difficult it becomes to thread the fine wire through the Teflon tubing. I had difficulty threading much more than three feet at a time - enough for a two foot interconnect. Also, you will use up your new wire faster than you think: it takes nearly 40 inches of silver wire to wrap around a 24 inch length of cotton rope if you space your "wraps" about 1 inch apart. Then you need to use another 40 inches for the second conductor. Now you have a single interconnect, but they are usually used in pairs, so you are looking at approximately 13 feet of silver wire per 24 inch pair of interconnects. Thus, one 25-foot spool of pre-insulated wire from A-M Systems, Inc will yield 2 pairs of 24 inch interconnects.

First, place some hobby oil in the end of the Teflon tube. If you simply touch the end of the tubing to a drop of the oil, it will wick in all by itself. Put about 1/2 to 3/4 of an inch of oil into the tube. This makes inserting the wire MUCH easier (trust me on this one!). 30 gauge wire is pretty thin stuff, and without the oil, you will surely kink and bend the wire and not be able to thread more than 5 inches of it into the tube. If you don't believe me, just try this without the oil and you'll see ;-). Thread one length of wire into each of the lengths of tubing that you have cut - these are your conductors. Next, its time to wind them onto your cotton rope.

Before you cut your rope, be sure to wrap it in tape, then cut through the middle of your tape. This will keep the rope from fraying and becoming hard to handle. I found it helpful to use a ruler and a sharpie marker and mark off one-inch intervals along the rope. You will use these marks as you wrap your first conductor around the rope to help maintain even spacing of the two conductors - an important part to achieving the low capacitance of the design. Begin by using a thin strip of masking tape to secure one end of the first insulated wire to one end of the rope. Then, start winding the wire around the rope so that you "hit" each of your one inch marks. When you get to the end, use another thin strip of masking tape to hold the wire in place - you don't want it to unravel now that you've wound it around the rope.. Do the same thing with your second insulated wire, but this time, you want to wind it so that it stays in the middle of one inch space created by winding the first insulated wire. The idea is that the two insulated wires should always remain 1/2" away from one another, thus never crossing over or touching one another. When you have completely wound both silver conductors around the cord, its time to use the Teflon plumbers tape to wrap the entire thing. Start at one end and be sure to overlap your spirals of Teflon tape to hold the conductors firmly in place. I usually wrap the rope with the conductors in place once in one direction (left to right) and then back again to where I started (right to left). This results in two good coverings for the rope and keeps things from moving around on you. Remove the little bits of making tape you used to hold the ends in place and go over the ends of the cord a few extra times with the Teflon tape to provide enough surface to insert into the RCA plug. You're most of the way there...

Before you get your soldering iron all warmed up, make sure you've done two things: 1) be sure to mark which conductor is which, you don't want to mix these up and short the output of your CD player (an ohm meter is an excellent tool to make sure you don't mix things up...) and 2) thread the barrel of the RCA terminal onto your new interconnect BEFORE you start soldering (duh! see the last picture above!). Its actually impossible to get the barrel back onto the terminal once you've made both solder connections, so do this part FIRST! It may also be necessary to shorten the wire and teflon tube if it overhangs the end of your cotton rope. To do this, gently score the entire circumference of the teflon insulating tubing with your razor knife. Don't cut all of the way through it as this will also cut your conductor and then it will need to be replaced. Once the tubing is scored, use your thumbnail to separate it, then cut your conductor to the necessary length. 

Next, make your solder connections and pinch the tabs of the RCA plug around the rope (not the wire!) with a pair of pliers. The last step is to wrap your solder connection with the same teflon tape to make sure that they are insulated and have no chance of wire or solder from the center pin contacting the outer barrel of the connector. When everything is neat and tidy, close up the RCA plugs. You're done! All in all, it takes about 45 minutes to make each 24" pair of interconnects.

Final Cost:

I have many many, many pairs of interconnects. I made enough for my own set-up, and have given several sets away to friends and family members who know enough to appreciate their qualities. While the total materials cost is fairly high (though still less than the cost of a single high end pair of interconnects!), the individual cost works out to less than $25 plus an hour of time for each pair of 24" interconnects. Certainly more expensive than the cheap crap that came with your CD player, but also far less expensive than ANY other medium to high performance interconnect available today. For the cost of a one meter pair of high end interconnects, I wired my entire rig (and I have a lot of wires!).

The primary determining factor for cost is the specific RCA connector that you choose. Don't be cheap here (probably $5 each is the lower limit that I would set). I don't really see the need to spend $60 on a pair of them, but hey, its your money...

Performance:

Well, I was duly impressed when I first replaced the stock RCA cords that came with my CD player with Monster M950i cables. I wondered just how much of a difference I would hear with these new cables. The differences were not subtle at all. First, I had to recalibrate the channel levels for my home theater setup. The silver interconnects made the whole system much louder. The silver interconnect was very similar to the Monster one in terms of bass, but the treble had improved dramatically. Many people call silver wires "bright" or some other adjective that indicates the treble is too loud. I don't find silver wire bright at all, to me, it sounds great! Switching back and forth between my DIY silver ICs and the Monsters (after balancing their levels with my SPL meter) was clearly different (my CD player has 2 outputs, so switching is literally as quick and easy as a button press on the remote control). Switching from my new silver wires to the M950i left the music sounding dull and lifeless. Switching back to the silver wires presented a wider sound stage, smoother and cleaner treble, and an overall more enjoyable experience.

Now some people will claim that you will not be able to hear a 2% improvement in conductivity rates, or that wires don't matter. I used to be one of these people until I tried this myself! Your results, however, will most certainly depend upon the type of equipment you are using. If you have an inexpensive rack unit (< $300) that you bought at Circuit City a few years ago, you are not very likely to hear much difference. Why? Because the overall quality and resolution of the system is not high enough to reveal this difference (a chain is only as strong as it's weakest link...). If you have separate components that you hand selected at various high end audio shops, the differences should be readily apparent. I have an Adcom GCD 700 CD player, a Marantz AV-9000 preamp, Marantz MA500 monoblock amps, and Atlantic Technology System 350THX speakers. Certainly not "top of the line", but in all ways superior to anything sold in Circuit City, Best Buy, or any other "mall" store.

Measurements:

There are really only three measurements that can be readily made on a cable. The table below is a comparison of resistance, capacitance, and inductance measurements among three RCA cables: the standard freebie that comes with your CD or DVD player, the $100 per 1/2 meter Monster M950i interconnect, and my own $25 per 1/2 meter DIY silver interconnects. The goal with designing any type of audio signal wire is to transmit and preserve, as closely as possible, the original signal. Therefore, minimizing each of these three measurements will result in a wire that interferes with the original signal the least - at least this is what one would hope for. In reality, it is sometimes difficult to correlate physical measurement with what we hear. So with that in mind, here are my measurements - for what they are worth...

Let me start off by saying that the lengths of these cables are not equal. The Monster IC and my silver IC are approximately the same length: about 20-22 inches. The length of the standard freebie IC is about twice that: 40 inches. It may not seem fair to compare unequal lengths at first, but since I know of no one who would actually spend the time to cut a stock IC, it seems reasonable to compare the cables as they will actually be used. Resistance and inductance were measured with my LCR meter center pin to center pin and outer sleeve to outer sleeve on the same IC. The "between conductors" measurements for resistance and inductance were made by connecting the center pin to one probe of my meter and the outer sleeve of the same IC to the other probe. Capacitance measurements were made in the same fashion as the "between conductor" measurements for resistance and inductance.

Well, I suppose its not terribly surprising to find that the standard freebie cable that comes with the average CD player measures the worst of the bunch (even if we normalize the readings by diving these measurements by 2!). Particularly interesting is the between conductor resistance and inductance measurements. The only reasonable conclusion to draw from the resistance measurements is that the material used to insulate the conductors from one another in the freebie cable is not really an insulator at all... The Monster cable measures less resistance than my DIY Silver IC, but that is to be expected to some degree due to the heavier gauge conductors found in the Monster interconnect (single 36 inch run of 30 gauge silver wire measures approximately 0.300 ohms resistance, a dual run of the same length measures about 0.195 ohms). The inductance measurements show no difference between the Monster IC and my silver IC; however, the capacitance measurement is higher for the Monster than for the silver IC. Capacitance is related to high frequency roll-off (that is why capacitors are used in speaker crossover networks!), but this difference seems to be relatively small. Either way you look at it, we have achieved Chris' original goal of an IC with extremely low capacitance!

Links:

Some Reading: Theory and construction

Super Cables Cookbook from Vacuum State - click on their "books" link on the left
Chris VenHaus's DIY Silver Interconnects: The original web site for the DIY interconnects
John Risch's DIY speaker cable and interconnect web site
Make Your Own Audio Cables: some reading on diy cables
Radio Shack Magnet Wire ICs: great sounding diy interconnects on the cheap
The $2.99 Silver Wire Trick: a quick rundown of diy interconnects by the late Dr. Harvey Gizmo
The Science of Cable Design
Wire Gauge Calculator
Interconnect and Speaker Cable Design Part I and Part II at EnjoyTheMusic.com

Suppliers:
Home Grown Audio: Supplier of Teflon insulated silver wire, braided wire, and silver cable terminators
Myron Toback, Inc. Supplier of uninsulated 30 gauge fine silver wire
McMaster Carr: Supplier of Teflon spaghetti tubing for insulating bare wire
A-M Systems, Inc: Supplier of Teflon insulated silver wire
Michael Percy Audio. Supplier of all types of high end, exotic, and esoteric components
Parts Express. Suppliers of various wire and cable terminators as well as other components