We all have our own way of doing things that suits us. A good friend of mine starts his annual stereo spring cleaning by first organizing the CD and records, then cleaning the hell out of the room, and finally, he gets down to the business of the equipment itself. His motto is, “clean first, organize second”.
I do the opposite. I start with the equipment and leave the clutter for last. “Tear apart, clean, organize and reassemble”. And I often do it in sections.
Whatever the order you choose, a good annual spring cleaning of the music system is a good idea and a wonderful project for Saturday afternoon. In fact, how about this Saturday afternoon? (hint, hint).
Turn the system off, disconnect every cable so that the equipment and speakers stand naked without any connection (including power cables). Once disconnected, I set the pile of cables off to the side and get out my cleaning stuff. For PS Audio equipment, I use Windex to get the dust off the outside. It doesn’t take long, though lifting the P10s and BHK amps off their pedestals takes help.
Everything gets a thorough wipe down. I use a bottle of spray air on the speakers drivers, then I reset all the equipment back up for best symmetry.
Yes, I am a symmetry freak and go nuts making sure all equipment on the floor behind my speakers are lined up perfectly. I actually use a tape measure and spend the time getting it right. Anal, yes, but I know when I listen to music any little bit of disorder interferes with my ability to relax. You might not care so much. Disorder drives me crazy. I have too often finished my work, lowered the lights, sat down in the main listening chair, turned the music on and prepared to bask in the glory of the sound – only to discover the spacing between two amplifiers is visually off. Everything stops, I am back at it.
If you’re like me, first step is to disconnect, clean, perfect symmetry before anything else happens.
With spring in Colorado we’re usually slammed with one or two wet, sloppy, snow storms that snarl traffic, break tree limbs and close the airport. Last week’s blizzard was no exception. The company declared a snow day and we sent everyone home to defend their driveways, shake the trees so branches could survive, and take care of kids.
I, on the other hand, decided it might be a perfect opportunity to spend some quiet time in Music Room One and fought my way through the snow to come to work. When I arrived the room was in disarray. We’ve been conducting a number of experiments, from MQA listening tests to playing with a new USB magic device that has me drooling….(and no, I’m not yet ready to talk about it). So, instead of listening to music right away, I rolled my sleeves up and started to clean.
You car seems to run better after you clean it, and it’s the same for our stereo systems. I think that’s because you’re more focused on relishing the positive aspects and ignoring the negative bits. But, whatever the reason, we all know it’s true.
Over the next few days I’ll detail some simple tips on tweaking your system.
We’ve likely spent enough time on grounding and I wanted to wrap this up so we can move on to new territory.
I had mentioned in yesterday’s post the problem with cable TV and its ground interference with stereo systems that often causes hums and buzzes. If you do run into that problem you can always disconnect the third wire ground of your power amp with an AC cheater plug – but that’s not always the best way to go. In fact, there would be many that argue it’s not a good way to go at all, less safe than following the rules.
The alternative solution is to disconnect the ground from the cable TV, but to do that you’ll need an isolation transformer. The one I used to recommend was available at the Parts Express here, but I see it appears to no longer be available. Here’s another inline version for less than $10 and looks similar though I haven’t tried it. If you ant the finest solution out there, you’ll need to pony up a few bucks. Jensen Transformers makes the Cadillac of them all, known as an IsoMax, and is available here.
Using any one of the transformers disconnects ground and galvanically isolates your stereo system from ground nasties provided by your friendly cable company. I had read somewhere that cable companies score lowest on customer satisfaction surveys, lower even than airlines whose customer service people are rumored to still wear clip on ties so they’re not jerked over the counter by some irate customer.
Here’s some bottom line tips you can use for best grounding practices.
If you’re looking for a good example of how some grounds are lousy, (and who isn’t these days?), all you need to do is turn to your cable TV connection.
It has to be at least once a week we’re called to help fix a nasty buzz in someone’s stereo system. Over the years, and hundreds of phone calls later, the first questions we ask concerns cable TV. If there is any connection to a cable TV in the system, chances of a nasty rasping noise blaring through your speakers is high. Disconnect the cable and bingo! no more buzz (no more TV either, but that’s another story).
The reason cable TVs are so problematic has to do with different ground potentials–a term you’ve no doubt heard bandied about, but maybe didn’t know what it meant.
When we speak of a potential difference we don’t mean to speculate whether there will or won’t be a difference. A difference in potential refers to voltage as measured between two points. If you were to take a voltmeter and connect its two leads between the incoming ground of a cable TV and the ground in your home, you’d measure a small voltage–a difference in potential. It is this small voltage that, when added to your hifi system, gets amplified into the nasties some we’re sometimes plagued with. And often the cure is to remove the house ground from the stereo with an AC cheater plug, though the right thing to do is to disconnect the cable instead.
I’ll cover an interesting solution to this problem tomorrow.
The optimum grounding scheme for any music system would be to have all your equipment’s grounds at exactly the same potential. To manage this near impossible goal, each piece of equipment, every cable, every connector, would need to have its own wire of identical length tied into the same ground point. Not going to happen.
What usually takes place is very different. In real life, we plug our equipment into various outlets, each of our connecting cables daisy chains from one piece to the next, and multiple grounding points are terminated at different potentials along the way. Hardly perfect, but then, there’s not much perfect going around these days.
So, as in most things in life, we need to look at what our next best option might be, and you might be surprised to learn you’re already doing it. What we’re going to want to move towards is called a star ground. Here’s what it doesn’t look like.
Sorry, couldn’t resist. This poor ship, called The Star, is certainly grounded. But what we’re more interested in looks like this.
A star ground is where all grounds tie to one point in the chain. The beauty of the star ground system is that varying lengths of each ground connection do not matter. So, this means you could have a power amp with a 10 foot power cord, a preamp with a 3 foot cord, all connected to the same star ground point and have no difference in ground potential that mattered. Long cords, short cords, daisy chained connections, all ok.
I mentioned you might already have something close to a star ground in your setup, and you just might. If you’re running your system from one power source, like a Power Plant, or a central power conditioner, chances are good you’re getting pretty close to the ideal ground solution already. Properly designed, a multi-outlet device feeding your system shares one ground and all outlets inside can be tied to one point.
There’ve been a number of questions sent my way about this grounding business and perhaps it’s worthwhile to touch on the opposite before we move forward with particulars about the grounded side of things.
Much of what we use in our homes is ungrounded. That means there’s no third wire ground connected at all. Shavers, nearly all bathroom appliance that aren’t a hair dryer, many consumer electronic items, clock radios, and even AV receivers. In fact, most items within our homes aren’t grounded, relying on the good old 2-prong plug that looks like this.
And if we’ve come to understand the third prong of a 3-prong plug is needed for safety and noise reduction, what’s up with products that don’t use them? Are they not safe?
For the most part they are safe but must be designed to a different set of rules than 3-prong electronics. First off, the 2-prong plugs are, for the most part, polarized. This means they can only plug in one way. You know, the plugs that are never turned the right way when you want to plug them in? The ones that always piss you off when you’re in a hurry?
If you look closely at a 2-prong plug you’ll notice one of the metal prongs is fatter than the other. Here’s a picture.
The fatter one is neutral, the smaller one is hot. Neutral is similar to ground in that you should be able to stick your finger into it without getting shocked (disclaimer for idiots. Don’t stick your finger in the AC socket). The idea here is that if your AC wall plug is wired correctly, you haven’t any choice but to plug the thing in correctly and safely.
Secondly, use of a 2-prong plug has other design considerations as well. Special rules apply as to how you isolate the electrical circuitry from the outer chassis and those rules are pretty strict. You’ll notice that many 2-prong plug units have plastic outer chassis, though not all of them. Most AV receivers are metal chassis and have only 2-prong plugs.
Some older homes have only 2-prong AC receptacles.
In short, properly designed 2-prong plug units are safe and more common than grounded 3-prong units, typical to high end audio.
Ouch. Those words from years ago still sting in my memory. When a crime had been committed in the McGowan household I was the first suspect (usually for good reason) and the procedure was to immediately ground me as the first step in any crime investigation, with worse measures soon to follow, depending on the severity of the crime and the fate of the judge and jury (my father).
Each of our homes, apartments, condos, are grounded to one point through the home’s electrical system. You may have seen something similar to this picture in your backyard.
A metal rod driven into the earth with a wire attached to it. This, or something like this, is the lowest electrical point in your home’s AC system. Grounds like these are installed mostly for safety and are required by law in nearly every country.
Power coming into your home is typically fed by two, or three wires from a transformer on the utility pole. These wires haven’t any connection to ground. Heres what the system looks likje.
Not everything in our homes uses ground and – and this is important to understand – ground is not used to conduct electricity. Don’t try this at home, but you could disconnect ground from Earth and little in your home would change, everything functioning as it should. All the power your home uses runs through the two or three incoming AC wires, not ground.
Ground is included mostly as a safety valve for us humans and a sink for unwanted noise for our audio equipment. Problem is, when we use ground to lower noise in our audio system–as in yesterday’s black hole example–the hole we’re sending our noise to is more gray than black. In other words, in a crowded community of homes and buildings, all that noise we’re throwing into Earth becomes the equivalent of a toxic waste dump. And to make matters worse, ground’s effectiveness changes like the weather; worse in summer, better in the wetter months of winter and spring.
For now, let’s start understanding how we deal with grounds inside the equipment we own, then we’ll move on to more grounded subjects. (I couldn’t resist the double puns here).
The perfect ground is a point that can absorb as much electricity as is thrown at it without changing its state. In other words, ground is like an infinite sponge that absorbs electrical currents. Perhaps an electrical black hole might describe the perfect ground even better. A point at which nothing escapes once entered.
I remember a few years back when I visited TAS Editor Robert Harley’s home. Outside his listening room he proudly showed off his ground sink. It was a crafted plot of land with a copper stake at its center and all the equipment in his listening room was tied to this electrical black hole. And Robert explained the difference it had made in sound quality was well worth the effort it took to dig out the hole and fill it with a conductive slurry. I was impressed.
And yet, even that superior grounding system had its flaws. The most elaborate grounding schemes for audio equipment can be found in some of the best recording studios. In these installations, there are two such electrical black holes: a technical ground and an AC ground. The technical ground ties the signal grounds of every piece and rack of equipment to this same arrangement of conductive slurry and copper ground stake. The key to this arrangement’s success is that NO AC equipment shares the same wire. Only signal grounds and chassis are tied here. Electrical grounds for the actual equipment’s power are totally separate and tie to their own electrical black hole.
Paying attention to this level of detail can have major sonic benefits and tomorrow we’ll delve even deeper into the subject.
There’s been much talk lately about grounds, or, perhaps grounding is just something that’s recently caught my fancy and that’s why I believe there’s been increased chatter. Whatever the case, it has captured my attention and I thought we’d spend a minute thinking about ground.
So, what is ground? It could be coffee after it’s brewed, dirt in the backyard, or a description of the lowest point in a circuit. Let’s go with the latter since I know little about coffee and less about dirt.
Today the term ground, as it refers to electrical circuits, is a generic term that has many meanings, but it wasn’t always so. In the early days of telegraph wires, somewhere around the late 1800’s, it had been observed that it wasn’t always necessary to build two wires systems. In the days when wire was a scarce commodity, this was a big deal. Turns out designers could string just one wire between telegraph stations and use the ground (Earth) as the second wire. This worked great for most of the year, but soon trouble erupted. Summer’s dried out the earth and it became less of an electrical conductor, and telegraph and telephone conversations started failing at that time of year. The situation got so bad that in populated areas where communications were critical, they often poured water on the ground to help signals flow through it. In fact, over time, they abandoned the idea of using Earth as the second wire in the two-wire system and returned to what worked always, two wires.
Ground doesn’t always have to involve the Earth. Think of your cell phone or any battery operated device. It too has a “ground” but there’s no connection with the Earth. In electrical terms, we more properly refer to ground on a battery device as the common.
But, whatever you call it, ground, Earth, or common, the term refers to the lowest point in the circuit. The point which we consider to be zero.
Achieving a good ground has major ramifications for stereo systems. Noise, hums, poor performance can result in less than solid grounds and tomorrow we’ll delve a little further.
Have you ever noticed how much your eyes can distort your hearing? For example, you walk into a room at an audio show and a pair of small speakers are playing. Your eyes tell you their size and your brain fills in the expectation of how they will sound. Small speakers have little bass and small sound. If your ears hear what your eyes first told you to expect, the universe is in order and you move on to the next room.
But what happens when what your ears hear don’t match what your eyes see? Then we’re amazed. “Wow, how could so much sound come out of such a small box?” Had the speakers been big, you would not be so surprised at the sound because your visual cues would match the audible ones.
Our vision colors our perceptions. It’s why many of us prefer to listen in the dark, or close our eyes when we critically listen.
Turning off one sense, heightens the others.