Here it is, the beginning of October, the end of summer. Close up all those open windows, isolate your listening room, turn out the lights, and let the music rip. It's Fall, the season when Audiophile's turn back to their first love, tweaking their systems for orgasmic listening. Admit it; you get as much joy out of a new tweak that improves the sound as you do a new sex toy.
As you can see, this is the 96th meeting for insatiable tweaks. That's eight years of monthly columns about high-end audio. When Steve asked me way back then to supply a couple of editorials for his new magazine, it was supposed to be a short term affair, but here I am still trying to add something to our hobby. Hopefully the columns aren't getting stale, as today's topic is the same as that in my third and many subsequent columns; electrical gremlins. Guess the problems associated with the high end have changed little over the years.
The past couple of years have been "the best of time but the worst of times" for audio reproduction. Why? Because the electricity feeding our homes has been getting progressively more polluted, but more and more manufacturers of high end audio and video equipment are realizing it and finding ways of combating the crap flowing into our houses from the local electrical company. This has been my major buggaboo for the past 20 years, as the juice supplied by my local utility, and probably yours, is piss poor.
To recapitulate previous columns, the ideal AC feeding your equipment would have the following characteristics, all theoretically impossible given the present system of electricity in our nation:
1. 117 to 123 or 220 to 240 Volts
2. Perfect grounding of all house electrical appliances to one ground with 0.00 Ohms resistance from each piece of equipment to the ground.
3. Sufficient amperage such that no sags will occur in current supplied to the equipment.
4. Pure 50 or 60 cycles per second sine wave
5. Perfect alignment of the voltage and amperage wave.
So what can occur that will mess up these values?
1. Voltage - As you all know, especially in the summer, brownouts can be a big problem. One can sometimes tell this is occurring as fans slow down, lights sometimes dim, and sound can become dark, constricted and congested. There have been instances at my house where the voltage has dropped to below 100 volts, at which point damage can occur to motors and electronics. On the other hand voltage can rise rarely to levels above 130 volts where equipment starts degrading or burning out. This occurs regularly when electricity that's been turned off due to storms, cars destroying telephone poles, etc., comes back on again in a surge.
The electric company is actually responsible for maintaining the voltage to certain specifications by your state's utility commission, but there are so many loopholes that it's meaningless. If you think you have voltage problems at your house the utility will bring out a device that will record the voltage for a day or two to prove to you that its within spec. Too bad the measurement is also meaningless, as only long-term fluctuations are visible on the graph, and the norm is considered to be +/- 15 volts.
More insidious are spikes of several hundred volts or even as high as 100,000 volts for very short periods of time, caused by lightning strikes, power spikes from large engines turning on and off, and even bursts of electromagnetic radiation from the Sunspots. Right now is the so-called Solar Max, the peak of an eleven year sunspot cycle, when major disruptions with tremendous voltage spikes can occur, all of which are out of the control of your utility. Just remember that the electrical grid is the biggest antenna in existence and picks up all sorts of airborne current of varying frequencies. These spikes will sooner or later burn out transistors, resistors, capacitors, etc. A solar flare at the last Solar Max took out half of Canada's electric grid.
The over and under-voltages can be controlled by equipment using Varistors, AC-DC-AC uninterruptible power supplies, variable transformers, etc., and the spikes by MOV's, and other suppressers.
2. Grounding. All houses in the US must have an extra wire attaching all receptacles to a grounding rod usually near the electrical service, but I'll bet that your rod is either too short, or the soil is too dry most of the time, or the connection of the house wiring to the rod is corroded or not tight, leading to poor grounding. Plus many of the AC connections especially in houses with aluminum wire or older outlets will be less than optimal. This leads to a voltage potential difference between the neutral and ground wires that may lead to hum. I found this to be a problem at my house. Luckily I had a cure; cleaning off the contact of the house ground to the rod with Deoxit, placing Walker Audio SST Silver Treatment over the contact area, and then running a grounding wire from the rod to my well pipe which is 500 feet long. For those attached to the city's utility system, you could also run a wire from the ground to the city water pipe as long as its metal, preferably copper. Unhappily this won't work for plastic pipes. Many of the outlets were also replaced with Hubbell Hospital grade units and at the same time the connections were treated with Walker Audio SST silver paste.
There may be resistance problems between the various pieces of equipment connected through both their AC and interconnects such that there is a potential difference between them that causes hum. This can sometimes be overcome by removing the ground of one of the chassis by using a cheater plug or disconnecting the chassis ground, or even cutting off the ground pin on your AC cord, but that will increase the risk of shock if there is a problem with the neutral wire. Remember I warned you.
Also, just having one piece of equipment where the internal grounding on the chassis is reversed, may lead to hum problems or distortion. There are actually some pieces of equipment out there with two prong plugs where the hot and neutral are reversed. Thus one needs to check each individual chassis while disconnected from the rest of the system by reversing the plug (using a cheater plug if necessary) and measuring the residual voltage on the chassis to the ground using a voltmeter. The lowest voltage to ground is best. Make sure you remove the cheater plug afterward as they will certainly degrade the value of your specialty AC cords.
3. Sufficient Amperage. Think of the amperage, or current as the number of electrons or workers needed to do a task. All of them have to pass through circuits and wiring to get to their job, and unless the passage is very wide there will be a resistance to their flow. The voltage is the force that is pushing them through. All components need varying amounts of these electrons to do their job and the amounts vary depending on the amount of work that needs to be done. Thus, no matter how steady the voltage is, if there is too much resistance at any point in the electrical chain, there will be a partial blockage in the electrons, and the higher the number of electrons needed, the more difficult it will be for a sufficient number of them to pass the restriction and do work. The combination of the number of electrons (Amperes) with the force pushing them (Volts) gives the strength (power) and the work (wattage) that can be done at a particular time.
In most houses, even those that are up to normal code, and especially in systems with high wattage amplifiers, there will at times be insufficient amps or voltage to do the work. Whether the cause is due to low voltage from the utility, an overloaded transformer at the street, a too low amperage house service, or less than optimal house wiring, the outcome is the same; poor transients, and sloppy bass. Remedies include asking the electric company to put in either a larger or your own house transformer, putting in a 200 amp or separate service for the media room, and/or running a thicker gauge copper wire and better outlets, preferably hospital or audiophile grade, to your system.
Another possibility is to add some sort of electrical storage at the system that can produce sufficient electrons at musical peaks. This could be an AC-DC-AC battery storage uninterruptible power supply (UPS) or a large transformer that can store energy. The UPS must be able to produce a perfect sine wave (more on this later) and the transformer must be built in such a way as to not restrict the flow of the electrons.
4. Pure Sine Wave. There is no such thing as a pure sine wave from the electric company any more. There are all sorts of junk riding on it that distorts it. Since the power supply is directly coupled to the output on amplification equipment and most motors base their rotation accuracy on the sine wave's purity, the distortions in the electricity lead directly to distortions in the music reproduction. Unless these distortions are filtered out, they will affect the sound. Garbage in, Garbage out as they say.
5. Perfect alignment of the voltage and amperage wave. This is a little trickier to understand. Think of the amperage soldiers again. They are marching in a zigzag pattern (sine) and are coming to a pass straight ahead. Only those that are progressing toward the pass (top and bottom of sine) are allowed through with maximum strength and how many can get through will be dependent on the push they are given (voltage). The maximum push can only occur at the peak and trough of the voltage wave. Thus if the two waves are not aligned and the voltage push comes before or after the peak of the amperage, fewer electrons will pass and each will have less power. Unhappily motors, large capacitors and inductors anywhere between the supplier and your room will cause a misalignment of the two waves.
Most power supplies for electronics have two functions; converting the house voltage to the several different voltages for the various circuits, some storage to regulate it so that voltages vary as little as possible, and converting the AC to as pure a DC as possible. How well or poorly this is done is dependent on the supply's quality; the size and capacity of the transformer, the stiffness of the regulation, and the number of stages of smoothing of the AC to DC.
There is no perfect power supply. Unless it's overbuilt, especially transformers and inductors, the flow of electrons will be constricted such that some power is lost and electron flow is constricted, with heat being the by-product. All act to change the flow of electrons from an alternating to a direct current, but it is theoretically impossible to produce a perfectly flat current without any wave in it. Usually several stages are needed to get as close to flat as possible, but each stage adds cost, complexity, and loss of power. The power supply is directly connected to the output of the unit through the various stages, all of which are made to use the DC power to amplify or in some other way affect the AC music signal while blocking the DC's passage through each stage. Thus, any AC noise from the house current, which is not filtered out from the DC, will be passed on to the final output.
So What Are These Effects & Their Cures?
1. Grounding: This is the easiest to pick up. HUMMMM! If its related to house wiring, get an electrician in to check all outlets for proper setup, and redo that old probably insufficient grounding rod and wiring. Possibly replace the wall outlets and coat the contacts with any of the many products to reduce corrosion and decrease resistance.
2. Voltage: High voltage or spikes degrade parts leading to poorer ability to do their job or even premature failure. Low voltage can lead to poor transients, constriction of soundspace and with mechanical equipment, such as turntables, CD players, etc., speed irregularities and even damage to motors. See below.
3. Sufficient Amperage: The more soldiers, the less strain is put on the system. (Think Iraq.) The current from the street through to the equipment must have as little constriction to flow as possible. Thus use over-rated wire, outlets, and have some sort of electrical storage as close to the equipment as possible.
4. Pure Sine Wave: While the above three concerns and cures can be controlled by the audiophile with the assistance of the electric company or an electrician, this and the following need to be performed by specialized equipment. All electrical equipment is set up to use either 50 or 60 cycle Alternating Current, and the purer the sine wave that reaches the equipment, the purer that the DC current will be coming out of its power supply. The whole process is sort of a purification first of the distorted AC wave by external processors to make it as close to a sine wave as possible, and then by the piece of equipment to make it as close to a straight line of voltage and current as possible.
The whole process can be thought of as functioning like a speaker bandpass crossover using either active or passive parts to minimize as many frequencies as possible above and below 50 or 60 Hz., without limiting the flow of the electrons at the proper frequency. As with crossovers, each step will decrease the unwanted frequencies but never completely eliminate them. The more steps, the purer the sine wave will become, but this leads to more parts and expense, and more resistance to the flow of the electrons, leading to a loss of power and production of heat as a waste byproduct.
Now some folks may say that high-end equipment power supplies should do this and many of them do to a degree. But even a company such as Bryston, which is known for their brick outhouse power supplies, now recommends upstream AC line control.
5. Voltage and Amperage Wave Alignment. This is the most difficult for me as a non-electrical engineer to understand both how it occurs and the solution. Capacitors and inductors tend to take the voltage and amperage waves out of alignment such that one leads or lags the other in time. (Perhaps Mr. McDonald will discuss this at the end.) Thus the push (voltage) is not maximal at the time when the electrons are at their peak (current).
Finally, in audio and video systems, there's a new anomaly of the 21st century, digital grunge. Every piece of digital equipment puts out noise into the neutral and ground and if any analog equipment is connected through the AC line, this noise will be fed back into them, over and above what the AC line is bringing in.
In other words, it's a noisy electrical world out there and in your media room, and unless you get some protection from it, you'll never hear your system at its best. Over the years I've tried myriad power conditioners, enhancers, AC-DC-AC converters, isolation transformers, capacitors, etc., some to poor and some to great effect, and am always looking for newer, more improved techniques to rid my electricity of distorting noise. Sometimes there's a step forward, and sometimes its a step backward, as none of these units do a perfect job without adding some sort of problem.
So What Should A Good Power Conditioner Do
First, eliminate as much AC line noise as possible. The ideal would be as a high order bandpass filter or crossover eliminating as much of the noise both above and below the nominal 60Hz. wave without attenuating or adding resistance to the flow of the electrons at 60 Hz.
Second, align the voltage and amperage waves to maximize the power and work of the electrons.
Third, Attenuate voltage spikes to protect equipment from them without adding noise or resistance to the flow of the electrons.
Fourth, eliminate hum by allowing all equipment to be plugged into a common ground.
Fifth, keep voltage sags or brownouts from occurring either by using batteries with DC-AC conversion or through variable transformers.
Sixth, use battery backup to allow safe shutdown of equipment when the AC fails.
Seventh, isolate digital noise from the analog side.
I've learned over the years that like the electricity they are trying to correct, most power conditioners are not perfect, and none alone can completely eliminate the above problems without causing others. If chosen properly through experimentation, some of these units when used in tandem can mitigate the side effects of each while adding to the advantages, but the opposite can also occur.
After many years of listening to my system with various conditioners in varying configurations, the best overall sound and video in my system until now has been obtained using two Torus Power Isolation Units (discussed here), at the wall with their massive transformers to store energy and act as a first stage for removal of line noise, directly feeding my high power amplifiers, while isolating the video from the audio and the left from the right side of the room by feeding the AC from them to two APC S-15 and two H-15 Power Conditioners (discussed here), which also allow a soft shutoff of my equipment when the electricity goes down.
That is until about two months ago, when editor Steven R. Rochlin asked me to evaluate a new product from John McDonald of Audience, LLC.
Audience adeptResponse aR1p
Audience has been around for a while, and most of their products have been given excellent ratings by several of the high end journals; for instance, an editor's Choice Award by The Absolute Sound. I was intrigued by a superb review in Stereophile last April by Brian Damkroger of their aR12 Power Conditioner, a 12 outlet unit with each outlet isolated from the others and thought about trying to evaluate it myself, but had become so enamored with what the Torus and APC units had done for my system that it slipped my mind. At $3800, it falls into the price range for most high end conditioners, and its little brother, the aR6, with six outlets at $2600, while a little less expensive, but still might be a bit too much for a decent percentage of high enders. Also, there are times when using a single outlet conditioner might fill the bill for some systems; for instance isolating video from audio, or analog from digital, all analog systems without any digital sources or power supplies, or for systems where components are spread out with long AC cable runs.
Enter the newest addition, the aR1p single outlet conditioner. Mr. McDonald has stated that it uses the same circuitry as its big brothers but with a more utilitarian build; a black plastic case with just one Hubbell AC output and either an IEC or three pronged input. Its innards consists of hand wired high end parts using Audience's 10 gauge wire, the same as in their power cords, Auricaps, non-resonant damping material and is cryogenically treated. At $495, its theoretically a steal compared to its bigger brothers if it functions as well, especially if you have an analog only system and don't need the extra isolation between components.
After discussing my system configuration they suggested sending four of the units and their matching power cords, and using the units alone without the Torus or APC or any other power conditioners. As I wanted to give them a good break-in through maximizing the current flow through them, I did go against their instructions and placed two of the four units with their supplied cables between the wall outlets and the Torus units, one to my video equipment, and one to the rear channel equipment to minimize break-in time.
Figuring that the Torus and APC units had completely alleviated my AC problems, and not expecting any change in the system, I was floored to hear a definite drop-off in electrical noise from my 108dB/W/m horn speakers. Measured with my Radio Shack meter, the room noise level dropped by about 2dB. While not a huge amount, it was significant considering that there were two of the best power conditioners and high end AC cables already in the system.
You may ask, what's the difference if a little noise is removed, as if one goes to a concert or listens to music in most environments, there is usually a 40dB to 50dB noise floor or more in the best of circumstances, and even the quietest listening room have more than 30dB of ambient noise. The answer is that a lot of the naturalness and feeling of being at the original recording space is how our ears perceive the lowest levels of ambiance and detail in the recording. Our ears want to hear the background information that gives us the perception of the recorded space and the more natural it is the less our minds have to work to describe that space. As much as it would be disconcerting to hear a concert in a completely dead space, we also don't want extraneous noise not on the original recording to intrude and take away that perception of a natural environment. Thus the quieter our listening rooms, and the more low level information is presented from the recording, the less our brains have to interpolate the proper space of the recording venue.
That brings up the second finding. There was more "there," there. One of the parameters that differentiates a high end audio system from the better run of the mill ones, is how the original recording space is presented in your listening room. While a very good system will make the musicians seem to be present in your room, which is not bad mind you, the best systems tend to dissolve the listening rooms walls and present the musicians in their recording studio or concert hall, especially with simply mic'ed recordings. The information that allows this is buried in the low level recorded information. Even with the best of systems, only at times when the electricity is at its quietest, such as in the late evening, will this occur unless the best of power conditioning is used. With the aR1p even fresh from the box, through the Torus and APC devices, the effect was the best I've heard in my room.
After two weeks of break-in, per the request of Mr. McDonald, the system was reconfigured, taking out the Torus and APC units and running different equipment configurations with the four aR1p units with their power cords, sometimes using a couple of high quality self-built power strips using Hubbell hospital grade outlets and audiophile grade IEC plugs.
First their power cords. They are very well made; per their literature, using Marinco and Wattgate plugs, multi-stranded very flexible cable built in such a way as to reduce resistance and impedance and thus allow better current flow and therefore, less RF into the room. Indeed, in using them in the regular system in place of my 50 amp rated more expensive Silent Source Cables, there was no discernible difference between them. Using the cords with the aR1p units for an analog only two channel system, the noise floor was about 2dB higher than using the Torus and APC conditioners in tandem, but about 6dB lower than straight out of the wall. A significant improvement for the price.
Unlike several other wall type units I've tried, there was no discernible negative effect on dynamics, especially bass, with no blunting of attacks or emasculation of the bass (i.e. no balls). On the other hand, the Torus units do a slightly better job at dynamics, but at a significantly higher price. Thus the units are not restricting the flow of current, and they are most likely working to align the voltage and amperage waves through power factor correction. The units have built-in voltage clamping to ground of AC transients, but during their time here we didn't have any electrical storms or power outages so there was no way of testing them for this.
Like other units out there, their biggest achievement is allowing the recovery of ambiance, hall and space information that is normally hidden in the noise floor of the system. The electrical noise transmitted along with the 60Hz. sine wave which shows up as increased hiss, plus sundry other noises, is significantly diminished by these units, allowing especially analog recordings to bloom out into the room similar to what one may hear from their system late at night.
Digital presented another dimension. Plugging my Esoteric DV-60 Universal Player directly into one of the units and the rest of the amplification equipment into the other three thus isolating at least the AC side of the equation further improved on the above. We have become so used to digital noise, even from the best units, which is being fed back through the neutral and ground to the other equipment, that until you hear a system which has attenuated it, one has not heard it at its best. The aR1p units did a superb job of not only isolating AC grunge, but also the digital noise being fed back into the system, even better than my APC units that do isolate the digital from the analog outlets.
The biggest improvement over the APC units and other conditioners I've tried, was a visceral feeling of rightness to the music, allowing my brain to feel more at ease with the illusion of being in a concert hall listening to live performers. This is one of those under-rated factors of listening that prevents us from feeling we are actually there. Like a magic trick which we all know to be an illusion, but if done properly allows us to actually believe we've seen something impossible, when the electrical grunge is removed from the reproduction without adding ill effects, the illusion is easier for the brain to assimilate and believe without working hard at it.
This is also true for the video side. Plugging one of these units into my DirecTV digital receiver and Vantage Image Processor and one to the Electrohome 9500LC projector, there was a definite improvement in both the colors and dimensionality of the image. Right at the screen, the scan line at 1080P were sharper and more distinct showing a tightening of the beam of the projector. I don't know how well this would work on a digital projector, but it was significant on this top of the line analog unit.
At $495 each without the necessity of adding another power cord as they plug directly into the wall, they are a true value, with you being able to buy 5 of these for the value of one aR6p and 7 for the value of the aR12p unit, with possibly better isolation. On the other hand, the larger units with their multistages may have better isolation, and maybe Mr. McDonald will discuss that at the end. (and possibly offer me a couple for review, hint, hint.)
Finally, going back to using these with the Torus conditioner and the APC, the biggest effect on digital was to plug each of the Esoteric and my Lexicon MC-12B pre-pro into one of the aR1p's, and use the other two between the Torus and the APC units. This gave the maximum benefit in my system for audio digital reproduction. With only four units to play with, the optimal placement for the entire system was one unit between the wall and each Torus unit, one for the APC H-15 unit feeding the video equipment and one for the APC S-15 unit feeding the analog equipment.
So how did they compare to the APC unit for power conditioning? While both do wonders for noise reduction, the APC has built-in battery backup for gentle shut-off in case of electrical failure, and twelve outlets with three separate circuits for $1400 list plus the cost of a good power cord. On the other hand the Audience units for the same price for four with the lack of cost for a cord would give four separate circuits if attached to good power strips, and on a high end system do give a closer illusion to the real thing but at somewhat more setup difficulty. For the best audiophile grade sound, the Audience units are the way to go. Wonder what their bigger brother sounds like?