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Going Green
from audioXpress October '08

The CES 2008 went green for the first time by promoting audio products using recyclable or green materials—an indication that the industry is starting to pay attention to the undeniable threat of global warming. It is the responsibility of the audio industry to green up, as other industries already are (e.g., the Green Computing initiative by the computer industry). Designing and manufacturing audio products in a way that minimizes the impact on the environment is a very important step.

Green Audio? The next, much more important step, is how we audiophiles make our contribution. Let’s acknowledge that the effort to produce eco-friendly products is a drop in the ocean compared to the environmental impact of using these products over time. Many of us enjoy our audio systems, for several hours every day, every week, every month, and that translates into many KWH (KiloWattHours) of electricity needed to operate our audio systems and that’s a way bigger threat to the environment than production of audio equipment itself.

If only 100,000 people in the US were to use an audio system consuming 2kW of energy, it would result in total consumption of almost 200,000 MWH, and that, in turn, would require some 13 million gallons of oil every year just to support our audio pleasures. (According to the Electric Power Research Institute, a world authority on electric power, it takes about 65 gallons of oil to produce one megawatt of power.) Is there a real opportunity for audiophiles to reduce that staggering number? Should we give up listening to music? Of course not, but there are some simple steps that can lead to Green(er) Audio that every audiophile should consider:

1. Simplicity matters. Simplify your system to eliminate unnecessary power consumption. Using an integrated amplifier instead of separate amp/preamp components or an integrated CD player instead of transport/DAC separates reduces the number of power supplies and can save considerable amounts of energy and materials (i.e., additional chassis, resistors, capacitors, transformers). A simpler system is much easier to match and requires fewer connectors and cables, so we can help the environment and benefit from a better sound, too (see the sidebar).

2. Lower power amplifier. Make environmentally sound purchasing decisions, and you will help both the environment and your wallet. Do we really need that 200W or 500W monster if similar (or better?) results can be obtained with 20W or 50W? The difference in energy consumption between a 20W and a 500W amplifier can be staggering in hundreds of watts of additional energy. Keep in mind that’s what we would be saving every minute, every hour, of our music listening. And you would keep more green in your wallet.

3. High efficiency speakers. Most energy is lost through inefficient conversions, such as the electrical-to-acoustical conversion in loudspeakers. With a more efficient speaker, the less power your amplifier needs to reproduce reasonable sound levels. Some loudspeakers are very inefficient (85dB or less), and some are extremely efficient (100dB and more). What does this mean in practice? Because the decibel (dB) is a logarithmic unit of measure, a speaker that’s 3dB more efficient will need just half the power (3dB = log2). To put it in simple terms, a 10W power amplifier will produce approximately the same power level on a 100dB speaker as a 300W power amplifier can do with an 85dB speaker.

4. Conserve energy. Turn off your audio system when you know you won’t be using it for an extended period of time. It’s surprising how many people simply forget and leave their audio systems on when they leave for work or a weekend trip. With a little attention, we can achieve both: help the environment and reduce our utility bills.

5. Recycle responsibly. Discard used or unwanted electronic equipment in an environmentally responsible manner. Electronic devices contain toxic metals and pollutants, which can emit harmful emissions into the environment. Never discard your unwanted electronics in a landfill; recycle them instead through manufacturers’ programs or recycling facilities in your community. Better yet, donate still-working electronics to a nonprofit agency.

If the same 100,000 audiophiles were to follow these steps and reduce consumption of their systems from 2kW to 300W—which is not hard to accomplish—they would save 11 million gallons of oil and put an extra $170-$470 into their pockets each year. They would probably enjoy better sound, too. We can make a big difference if we apply some of the steps above, and we start pushing equipment manufacturers to make more energy efficient devices.

The point of this letter isn’t to suggest radical changes and forklift upgrades in our carefully tuned systems, and it certainly isn’t to disparage any type of equipment or specific vendor. But the fact is that we all can and should work to make our environment healthy for the long term. As noted, even small changes by many people can produce big results over time.

Mike Zivkovic
mike@teresonic.com

Should We Simplify for Better Sound?
All of us audiophiles are on a quest to build that ultimate sounding system. Many, if not most of us, take a best of breed approach, picking and choosing the best components we can afford. Many spend years and thousands of dollars in search of that perfectly matched system, but rarely attain the perfection they seek. Simple math explains the problem.

Matching a five-component system (CD player + integrated amp + speakers + interconnect cables + speaker cables) involves at least 32 combinations if there are only two candidates for each component. If there are three candidates the number of combinations grows to 243, and for four candidates of each component the number grows to 1,024, and so on. The formula is simple T = CN (where T is a total number of combinations, C is the number of components in the chain, and N the number of candidates for each component).

On the other hand, an 11-component system (CD transport + DAC + preamp + power amp + speakers + sub + five sets of cables) involves a minimum of 2,048 combinations with only two candidates, 177,147 combinations with three candidates, and over 4 million combinations with four candidates. Don’t forget: Complex systems with many separate components and high power amplifiers tend to consume more material and much more electric power as well.


Soldering
from audioXpress October '08

I was pleased to see Ed Simon’s article (“Soldering: A Tutorial,” March ’08, p. 42): Soldering is a very important topic that is given far too little attention today. I figured I’d add a few comments about irons, and a few more tips about soldering. I was an assembler and an inspector on mil-spec electrical components many years ago, so I have had a bit of practice—and some experience—with what can go wrong if you don’t do it right.

First, I should say that anyone who expects to do any serious soldering should invest in a real temperature-regulated iron—one that uses an actual sensor and feedback mechanism. Not only will it heat faster and make the job easier, but it will actually make you much less likely to damage expensive components and PCBs, and improve your results dramatically. Also, being less fussy, it just makes soldering much more fun.

With a non-regulated iron, you are basically forced into a situation where the end of the tip mounted to the iron is too hot, and the loss of heat into the work is used to produce a useful temperature at that point. The narrowness of the tip constricts heat flow so the temperature at the work is “loaded down” to what it should be. It is this dependence that requires you to use a narrow tip for fine work, and a heavier tip for heavier work. This produces a situation where, no matter which tip you use, you are quite likely to end up with the wrong temperature at the tip when soldering work of different sizes and thicknesses. You also tend to have situations in which it takes several seconds to reach the right temperature, and the temperature keeps rising if you maintain contact too long. This makes it easier to overheat what you’re soldering—which can ruin parts and, especially, circuit boards.

In contrast, when using a regulated iron, the back end of the tip is held at or near the correct temperature—or sometimes the sensor senses the temperature inside the tip itself. This allows you to use a fatter, shorter tip (which tapers to the same narrow point). These tips are designed to conduct heat well rather than to produce a drop along the length of the tip, so they produce the same correct temperature even with different types of work—which is what you want. You just need to ensure that you use a tip heavy enough to carry enough heat to the work. (I always preferred a short, fat cone, which tapered to a fine point, for most work.)

When choosing an iron (I can’t speak for recent models), I always looked for a heatproof cord. With the old Weller WTCPN and Hexacon models, both the power cord and the cord between the handpiece and the base were made of some sort of high-temperature rubber which survived resting directly on the heating element of the iron for an extended period (which does happen occasionally if you’re not careful). They also used some sort of high-temperature plastic for the ring around where the iron sits— you shouldn’t need to be that careful not to melt something. This is a very worthwhile feature to check for.

As for soldering, I will repeat a few oft-repeated instructions (you might consider this “Soldering Tutorial, Part 2”):

1. Always heat the work, or at least both the work and the solder—do not melt the solder and then “wipe” it onto the work. If your work isn’t hot enough, you will glue it instead of soldering it—which is electrically inferior and will not hold.

2. Always make sure that your work is mechanically connected before soldering it. If the work moves while the solder is cooling, you will get a weak joint that will look awful and probably fail. Also, solder isn’t mechanically terribly strong—it is always preferable to have an actual mechanical connection anyway. If you can’t wrap the wire around something, or put it through a hole, then either clamp it or hold it very still so it cannot move for the few seconds while the solder hardens.

3. Unless your component leads and wire are pristine, it will help a lot to tin them first. If they’re so dirty, or of inferior metal, that the solder doesn’t want to stick, you can use flux (it’s easier to get flux off a separate component than off a connection inside your project). This lets you use even slightly corrosive flux—because you will be able to thoroughly clean it off. Clean it by washing the entire component in some solvent such as isopropyl alcohol, then rinse it again to prevent sticky residue. Most modern components are designed to survive being washed (but exercise caution with unusual or “audiophile, hand wound” components). If you can’t get the lead or wire to tin, then discard it—if it won’t tin then it won’t solder properly. Most modern components are pre-tinned, which is helpful, and you really needn’t tin silver- or gold-plated leads as long as they are clean.

(With a really old salvage part, you can try repeatedly scraping, fluxing, and tinning, as long as you clean well and the part itself isn’t heat sensitive. If it’s a cheap or replaceable part, discard it, because it isn’t worth it. Usually, if the part or lead is something solderable such as copper or steel, the problem is dirt—or possibly epoxy or melted plastic. If you actually succeed in exposing bare metal it should be possible to tin it. Also remember that some components have tinned aluminum leads, or sometimes stainless steel. Electrical solder will not stick to aluminum or some stainless steels, so, if the tinning is gone from leads made of them, they cannot be retinned—period—discard the part.)

4. Always make sure wire, component leads, and PCBs are clean. The purpose of flux is to prevent oxidation in the time between when you clean everything and when you finish soldering—electrical flux is not intended to burn through dirt and oxide (at least, not the kind you should be using in high-end electronics). It is perfectly acceptable to clean PCBs and component leads with fine steel wool (unless they are made of some odd material, such as aluminum plated with tin)—then clean them with isopropyl alcohol. Even the grease from your fingers will tarnish clean copper over several days—and may make it harder to solder. Clean means clean.

(In “the old days,” it was common practice to use what was known as “mildly activated flux.” This means that the flux was slightly corrosive—even at room temperature—and had to be cleaned off thoroughly after you were done or it would eventually corrode your project. It did, however, have the benefit of being able to burn through a little bit of crud. Modern flux, however, is designed to be non-corrosive at room temperature. This is because, in many projects, you will not be able to thoroughly clean the work after you solder it.

For example, soldering those wires from the binding posts to the PCB. Unless you are prepared to immerse your entire project in a tank of solvent, which would probably mess up the paint, you cannot clean them thoroughly. While brushing them with solvent will make them a bit cleaner, it will also spatter some flux around the innards, and won’t remove all of it. Modern flux is designed to be mostly harmless if this happens. Good old Kester “44” will corrode everything in sight, and eat the paint, in a few years.)

5. Use good modern solder. Modern solder intended for electrical assembly uses a flux core that is intended to be non-corrosive at room temperature. In some cases, a special flux is used that is claimed to be so inert that you needn’t clean it at all (it hardens to a non-sticky shiny texture). While I would still clean it if possible, it will surely cause less damage than the old stuff if you miss a spot. Don’t use some old roll of solder you found in a drawer or toolbox; it might well contain corrosive (or no) flux core, which could ruin your project. You also don’t know what composition or temperature it is. Invest in a new roll of 0.062" SN 63 solder from a reputable electronic parts supplier. (I probably wouldn’t trust something in a blister pack from a hardware store either.)

Absolutely do not use flux intended for plumbing—it will contain corrosive acids. In general, if your work is clean, the flux in the solder should be quite sufficient. If you are salvaging old components, or using old components whose leads are really cruddy, use steel wool or a file, or even a knife blade, and “active” flux only if necessary to tin them, and be sure and clean it all off before assembly. Wash in solvent, then rinse in clean solvent.

I tend to avoid the “water-clean” fluxes—all the ones I’ve seen simply don’t work very well. You will probably want to avoid the “ROHS compliant” solders and fluxes as well. ROHS is a new European standard that requires devices and components to be lead free—so ROHS compliant parts have no lead, and are not tinned with lead-content solder. ROHS compliant appliances and devices have no lead solder in them. ROHS compliant solder uses other metals, but no lead and should be able to be used with lead-containing components. While ROHS may make good sense environmentally, or even in terms of safety, most people I know agree that the current products are less reliable, and more difficult to work with, than lead-based ones. They are certainly less reliable unless used exactly as intended, and so are definitely not for amateur soldering. (The ROHS fluxes may be just fine, but are probably optimized to work best with ROHS non-lead solder.)

6. Solders. There is another reason to use “eutectic solder” besides a low melting point. Many (most) alloys harden over a temperature range of several degrees—they become gradually harder as they freeze and eventually solidify. Eutectic alloys harden suddenly at one temperature. In soldering, this is important because it is difficult to prevent some movement of the work. If the work moves while the solder is in the process of hardening, the result will be an ugly connection of questionable strength. Eutectic solder, because it freezes suddenly, makes this much less likely. This is especially important if you aren’t an expert solderer. “SN63” is the standard eutectic solder used for most electronic applications—it works best in most applications. All other varieties should be considered “special purpose,” and should be used only if necessary, and you know how to work with them, because they will be more difficult to work with.

Another favorite is “silver content solder.” When intended for electrical purposes, this usually means that between 1% and 3% silver has been added to lead/tin solder. Silver content solder is often used in high-frequency radio and microwave applications, and has slightly better electrical properties at those frequencies. It is claimed to be slightly stronger, and usually melts at a slightly higher temperature—it is not-eutectic. Personally, I would not recommend this for beginners because, being slightly hotter and non-eutectic, it is harder to work with, and has no benefits at audio frequencies that I am aware of. It doesn’t cost more than a few cents extra, so, if you really want to, go for it—just be extra careful that the work doesn’t move while cooling.

I won’t even mention low-temperature solders for surface-mount components and the like. All of them should only be used if necessary, and only after you become very familiar with them.

Kits. Some kits come with nice normal SN63 solder. If I bought a kit that came with a coil of no-name solder wrapped around an index card, I would probably toss it out and use a roll of something known. It’s probably just fine, but why risk ruining a project because they wanted to save 50 cents?

Some “audiophile” kits undoubtedly come with “audiophile solder” as well—possibly silver content solder. While there’s nothing wrong with it, be aware that it will be more difficult to use than plain old SN63—and you will need to be especially careful to not allow the work to move while the joints are cooling. (I stress this because you might be surprised if you’ve practiced with SN63.)

For the newbies: PRACTICE. If you’re planning a big project and haven’t soldered before, it is a good idea to practice. Get some cheap components, tin them, solder them into an extra board you have lying around. Buy and build a $20 kit with a few parts before starting on that $1000 gold-plated tube amp. Look at the resulting joints with a magnifying glass. Have someone else who knows how to solder look at it if you aren’t sure. Soldering is something that you get a feel for. If you lack confidence and solder tentatively, you will be much more likely to do a bad job—or even damage something. You’re much more likely to do damage by underheating something then going back and back to reheat it, and going back to adjust it, than you are by overheating it.

Get good tools, including a good temperature-regulated iron. A beginner needs one much more than an expert—it will make it much harder to make a mistake, which will improve your confidence, which will improve your odds even more. Buy a nice roll of modern SN63 eutectic solder from a reputable parts house. If you’re planning to sink a lot of effort, and possibly a lot of money, into building a project, it’s well worth investing in a good iron and good solder—you’ll achieve better results, have fewer problems, and enjoy the whole experience much more.

One last tip: use Teflon wire, which is cool for many reasons. Teflon is a good insulator, and it withstands solvents almost absolutely. But the best thing about Teflon is that it withstands high temperatures. It is almost impossible to melt Teflon insulation with a soldering iron, which makes it much easier to use for interconnections—you won’t melt it while soldering it, and you won’t melt it if you brush the iron against it. You also won’t melt it while applying heat-shrink to it.

The downsides are that Teflon is more difficult to strip and costs more. Also, while Teflon is very resistant to abrasion, it is sensitive to pressure creep. If you clamp Teflon wires tightly or force them tightly against metal parts, such as pulling them too tightly against sharp corners, the Teflon may eventually “squish” out and expose the metal. This isn’t a problem per se, but means that you must be careful in this regard. I strongly recommend using Teflon whenever possible (any parts house or eBay sells it). Also note that Teflon, when burned, produces nasty fumes—this is not a problem if you solder it, because it won’t even melt, but might come up if you use one of those wire strippers that melts the insulation. Do not point a blowtorch at Teflon.

Keith Levkoff
kLevkoff@panix.com

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