It is easy to forget that the AC power coming out of your wall outlet is unimaginably “dirty.” Ideally, the AC power should look like a perfectly smooth sine wave. In reality, the AC can be corrupted with noise and distortion (dirty AC power looks pretty jagged and ugly on a scope, and in many cases turned nearly into square wave). This noise can easily be heard as buzz and hum which results in graininess and a general smearing in the music or can be seen as added grain and lack of details of the video image.
How can these AC power corruptions be dealt with in order to achieve optimum audio/video system performance?
First and foremost: separate your AV system from the rest of your house by using a separate circuit for your AV equipments. This is because fluorescent lights and lamp dimmers can be very noisy to the point of causing a very audible buzz through an audio system. Second but mostly ignored: AC power. This is such a complex and misunderstood subject.
To “cure” the AC power problem we usually are bombarded with various “power conditioning” system starting from the questionably yet curious $10 solution and the price only goes up from there. However, all of these variations can be grouped into two categories. Currently in common use, and the cheapest, is the filtration method using Pure Passive regulation. A pure passive power conditioning design is an implementation of various types of passive noise filtering such as inductors and capacitors of varying quality and size. The best of this type of conditioning will have independent filtering for each outlet with the filtering covering a broad band of frequencies. The very best of this type will also pay particular attention to having very low DC resistance from input to output insuring full peak power delivery. This is particularly important for preserving system dynamics. However, most of these systems are not properly designed, resulting in a loss of sonic dynamics. This occur due to the fact that amplifiers draw far higher currents at dynamic peaks than the average value. DC resistance in the power circuit will cause a voltage drop, compressing this peak power draw leading directly to compression of sonic dynamics. Alternatively, there is an active system which will be either partial correction/replacement, or full regeneration of the AC power using batteries such as uninterruptable power supply from APC or TrippLite. Some work very well for low-power type front end equipment (such as a CD or Blu-ray players). However, active regulation will always limit dynamics and current delivery when used with power amps. Active regulation can also introduce other problems into the regenerated/regulated power, including reduced peak power delivery and broadband noise.
The second yet the best approach is Isolation. The isolation of AC power input from the output is always implemented with a transformer. By nature, transformers inherently “separate” the incoming AC going into the primary winding from the outgoing AC from the secondary winding with no direct DC connection. Isolation transformers will be one of many differing types, from a simple standard EI core design or to a more complex balanced power toroidal type. Input/output (I/O) isolation can also be implemented with a magnetic amplifier type transformer implemented as a ferro-resonant regulator/isolator. All ferro-resonant-type transformer units of necessity must be big and heavy to allow full system dynamics and power delivery. Ferro-resonant units can be, and most are mechanically very noisy giving off a power line frequency noise/buzz requiring installation in a remote location. Larger units may also require a dedicated AC line.
Furthermore, balanced power isolation also can be very effective in reducing power-line frequency noise if it is compatible with all the equipment being powered. This balanced power is implemented by splitting the AC voltage into equal but opposite phase voltages that are balanced from ground. This can prevent corruption of the ground as the noise will also be equal but opposite thus cancelled out. This balanced isolation using toroidal transformer method that is used by hospitals, military and laboratories around the world since it is the best way of cleaning the AC power.
Too many people do not understand and/or discredit the use of power conditioning in high end audio. This is understandable due to some of the bad effects that come along with many power conditioning products (usually the cheaper kinds). One must understand, however, the fact that all of our electronics are simply modulators of AC power. Transforming this AC power into useful forms doesn’t change this basic fact and the end result can only be as good as the power that we start with; thus, the need for a properly designed power conditioning products that do no harm.
I have to admit although I’ve never personally used a Torus Power product, I’ve been recommending the products for the last 3 years or so due to their logical and no hocus-pocus approach to their power filtering system. As far as I know, Torus Power is the only company that exclusively use giant sized toroidal isolation transformer as the heart of their power conditioner. Other manufacturers that I have tested use various capacitors and a whole slew of tiny-sized components to do the filtering. Many even use AC to DC to AC conversion which all in all, although in theory can produce clean power, won’t have enough reserve power needed for transient power needs especially in the amplifiers side of the audio reproduction.
Furthermore, all of Torus Power system, due to the use of toroidal isolation, isolates any equipment plugged into the unit from the power grid. Using Narrow Bandwidth Technology, these units also act as a low pass filter attenuating noise prone frequencies that creates such as buzzing and humming. And as previously mentioned above, by having low output impedance and their custom designed transformers, they can provide higher dynamic and continuous flow of power to the equipments plugged into them.
Of course for the higher end model, Torus Power also includes Series Mode Surge Suppression which completely non-sacrificial unlike regular MOV by absorbing the surge and bleeds it to the load gradually to avoid potential ground contamination. They even meet the IEEE endurance standard of 6,000 V / 3,000 A with 1,000 repeats!! With regular MOV used by cheaper power conditioners they can only protect once and you’ll have to throw away your power filter.
For us who lives in the Greater Toronto Area, and other areas where power sags happen easily 10-20 times a day, Torus Power AVR series include Automatic Voltage Regulation that accepts voltage anywhere from 85V to 135V and boost or clamp as necessary to the save operating voltage of 115V to 125V.
I’ve been a backer of clean power for years due to my background in music production. In the studio, most inputs were low-level inputs that need to be boosted to high heaven in order for it to be able to be recorded. The microphones, for example, needs to be powered with 48V Phantom Power, then boosted with tube-based pre-amp then dynamically compressed by a minimum of 8:1 ratio and in most cases infinity:1 ratio!! This will not only boost the sound coming into the microphones, but also any hum, buzz, etc that comes with it. Multiply that with multiple inputs, if you don’t have a clean power to begin with, you’ll end up with a very dirty sounding recording.
So now, 14 years later, even for my dedicated home theatre I use two dedicated lines; one for digital and another for analog equipments, separated from the rest of the house. Those lines are then filtered further by two (one for each line) electrical filters identical to the ones used by hospitals in Japan. When comparing the sound and picture between shared outlets versus the filtered dedicated outlets, the difference is very revealing. No hum, hiss or buzz even when pushing the output to the absolute maximum unless I put my ears literally next to the speakers. Music sounds extremely clear and video presentations are pristine too.
So when I was offered by Torus Power to try out their AVR-series power conditioner, I’m interested to know how much better the sound and picture can be. After all, as mentioned previously, I’m already using dedicated lines and hospital-grade power conditioners.
After taking multiple stops carrying the behemoth heavy-as-an-truck power conditioner to my equipment room (this AVR2-20 is so heavy it requires both James Drew from Torus Power and myself to bring this thing down), re-plugging everything to the power conditioner, I heard something that I’ve never heard before in my dedicated theatre room. It was the deafening silence emanating from the speakers. Not even when I put my ears next to any of the speakers. Nothing…nothing at all. Even James Drew can readily hear the difference between using the Torus Power against my already-filtered system. The background sound is now non-existent, there is not a single hint of sound even with the volume control turned all the way up to the maximum. None whatsoever.
I always thought the difference between my already-filtered system versus filtered-by-Torus AVR 2-20 will be minimal. This is not the case. I was wrong. So very VERY wrong.
What astounds me more is that although I’m not dissatisfied with the dynamic delivery from my receiver the Pioneer Elite SC-75, I sometimes feel wanting more. I’ve always fault the situation from my use of receivers’ internal amplifiers instead of separate power amplifiers.
With the AVR2-20, I can even visually see the difference between the projected image between my current filtered setup against the Torus filtered setup. Slight, but noticeable not only to me but also to every guest I invited to my dedicated home theatre. But by golly, the sonic differences are tremendous. Instead of spending the money to upgrade my receivers’ built-in amplifiers, I can just spend the same amount of money by buying the Torus AVR-series power conditioner. This way not only I save money from not having to pay extra money for the electricity to power those extra power amps but I can also save some carbon footprint as the result in using less energy from using a set of larger amplifiers. Plus, as a bonus, I’m lowering the system’s floor noise at the same time.
Take for example the continuous bass-drum kick in “End of Days”. It feels tighter and a lot more taut in a continuous manner from the beginning to the end of the movie. The punishing “Burlesque” final scene from the blu-ray of the same title that usually put my receivers’ amplifier out of breath was produced nicely with all its details intact without a hint of fatigue.
Last but not least, this power conditioner also comes with a programmable outlet that is designed especially to turn on/off a modem/router system. I find this function to be extremely helpful because I can just program the unit to kill the power to my modem/router system at 1am every morning and leave it off until 6am. This way not only I further save some more electricity, I can flush the cache memory and cool down my network system automatically and it forces me to not use the internet using those hours and give me a good excuse to actually take some time off the internet.
So all I can say is, before upgrading your equipment (provided you already have a professionally calibrated and relatively decent audio video gears), upgrade your power conditioner and you’ll be surprised how much performance have been hiding due to the un-conditioned power in your house regardless how clean you think your power is.
As for myself, this AVR2-20 will be part of my home theatre system and will be part of any of my future reviews be it an equipment review or a movie review. James Drew of Torus power has to pry this unit off my cold dead fingers if he wants this review unit back!