AC Line Conditioners

Several questions have come up about regarding UPS units, line conditioners, surge suppressors, ground loops, and even power cords. I made a feeble attempt to answer some questions and offer some information, but always felt I was omitting something. Then it came to me. I hope the following information will be helpful to everyone.

Back around the mid to late 1990s high end audio manufacturers began to seriously address the problems with AC line generated distortion, especially when it effects the conversion of AC to DC inside the circuit design. The various techniques employed originated from other industries like x-ray machines, mass spectormeters, quality control instruments, computer boards, and even electron microscopes.

It seems like a simple line from the wall outlet to the circuit board, but broken down there are quite a number of factors that come into play.

Audio equipment manufacturers are aware of poor AC current and include line filters, conditioners, and basic surge suppressors into their designs in various degrees. There are a number of techniques employed, including separate power supplies. Depending on the component, some types of independent line conditioners and suppressors can actually cause an incompatibility which effects the performance and sound quality.

Few of us employ an electrical engineer who can examine a schematic and recommend a compatible AC line conditioner. One could ask the manufacturer which units perform well with their products, perhaps you may receive an informative, qualified answer, perhaps not. The units I use have been through trial and error. It may be the only solution.

I actually employ an electrical engineer at one of the small businesses I own (a large format digital image shop). For the computers, printers and servers we use an active surge suppressor made by Brick Wall. They have a very interesting web site

http://www.brickwall.com/

My engineer also referred me to a very informative article from Sound Stage on the subject.

http://www.soundstage.com/articles/pete03.htm

The type of AC power units we use for our computers and hard drives are completely different than what may be required for our audio components, including DACs. Protecting and enhancing the performance of our equipment requires serious consideration, but beware, it can become a daunting task in the face of part advertising hype, part complex electrical science, and a dash of snake oil.

Daphne

Speaking only about the music there is no doubt AC plays a huge part on sound quality. I remember years ago reading about very expensive power cables/ ends/receptacles and laughing. No longer. I don't have a budget for the high dollar isolators, filter regenerators and the like, but most have the budget for dedicated lines, quality outlets, and a couple of well placed isolation transformers. That alone can be a bigger improvement than a dac or sound card change, for example. I went to balanced power 2 yrs ago and have never looked back. Nobody in this hobby can truly evaluate the sound of their system without being reasonably confident they have done (to the best of their budget) a good AC audit starting at the breaker box. There is a phenomenal amount of physics involved with AC transmission leaving us mere mortals best suited to keeping a sharp eye on the subject and experimenting with what sounds like it might be reasonable or necessary for our particular systems. Also Daphne, agreed, the snake oil................

Daphne, thanks again for your insight. "The units I use have been through trial and error. It may be the only solution."

Most times listening to units or components through trial and error is the only final solution. Knowledge and expertise in audio design, electrical engineering, test equipment and measurements all help. Research, reading and respected opinions of others often form a good starting point. But at the end of the day it is thorough crititcal listening that determines or discerns the better or worse.

Snake oil, there's plenty of that, though more often it is marketing hype from someone trying to sell their product. Propaganda and invalid criticisms abound.

Critical listening takes time, patience and unfortunately more money to try out alternatives. Some components take hundreds of hours to break in and bear audio excellence. A/B comparisons, blind or double blind testing can all be useful, but these methods can also be unreliable for new components or equipment.

Perfecting our audio systems takes hard work, but it can be a lot of fun. Consider for a moment a few of the sonic characteristics effected by our choices: tonal balance, soundstage, depth, detail, transparency, dynamic range, frequency, naturalness, rhythm and pace, coherence, imaging, silent background, transients and focus. There may be ways to measure these that I'm not familar with, but I rely on my ears.

Specific to your forum topic, power line choices can make a significant difference. I have a dedicated lines for audio and different power cords sometimes have different sonic signatures. Out of several cords I evaluated recently, on a scale of 1 to 10, I rated three at a 4, two at a 5, two at a 6, three at a 7, one at an 8 into a Brick Wall unit or a 9 running naked into the Oyaide wall outlet. Some of my criticisms include bass heavy, glare, midrange not right, reduced soundstage, detail lacking and coherence a tad low. Bargain quality power cords that I would rate a 6 or 7 include the VH Audio Flavor 4 or the DIYCable Asylum power cord.

I have found only a slight sonic degradation with either the Brick Wall or Zero Surge units but they provide a level of protection for my equipment that I hate to be without. To put this into perspective, I also feel that a volume attenuator has a slight degration on the fine sonic qualities I am trying to achieve, but some sort of volume control is usually necessary or convenient.

How about going all battery operated?......

I use a Furutech E-TP80 and the Almight Omega Mikro Active Plane Power cord! These totally loeer the noise floor!

I use Singal Cables Power cords on the amp, preamp, dac.

Liz

I'll second wappinghigh's question in a little different way. What about an alternative energy system (ie. solar, wind) with a battery bank and inverter. Would this produce better power than the main grid?

I have a DAC that runs on batteries. There are quite a few high-efficiency, low-power amps, like class Ds, that can run on battery power. There are even a few high-power amps that can run on batteries. When I saw those big Vienna Acoustics I posted about, they were being driven by a pair of huge battery-powered mono blocks. I didn't ask the cost. I'm sure it would have been frightening. But the bottom line is there is no need to be taken in by any snake oil in this area. The consistency of power can be measured. We have a handful of power centers running all the time at the store and I don't think I've ever seen one of them vary enough to effect the performance of a well-designed amp. Noise in power can be heard (or if it can't it doesn't matter). Make sure your equipment is protected from surges and spikes, and listen to it. Do you hear noise? Power conditioning might help. I'd try a different outlet first, but it might help.

The big proponents tell me that power conditioning also extends the life of your equipment. I tell them that I'm still powering my headphone rig with a Harman Kardon integrated amp I bought in 1972, and it doesn't even have a grounded plug (and it has a very low noise floor).

Two pieces of advice from someone who sells this stuff:

1) The mark up in power conditioning is huge. Your retailer has a great incentive to add it on to your purchase.

2) If you spend more than a couple of hundred dollars, even for multi-stage protection, you are buying a lot of mojo with your functionality.

Tim

I must agree with nanofarad, he pretty much offers a summation of the situation in few words. Switching to dedicated lines, an isolation transformer - balanced power, a good dedicated surge suppressor, and quality outlets will offer a surprising difference. In my experience, through trial & error, and listening tests, I'm not really sure how much of an improvement, beyond this point, additional line conditioners can make. Then again, who knows, it all depends where you reside.

I live in Southeast Florida (Palm Beach county) where AC current can be as bizarre as anyone can believe. In my office building I have three Brick Wall active surge suppressors mounted on the wall next to the main circuit box. Each surge suppressor is dedicated to the circuits which power top quality wall outlets for office equipment (Fax machines, copier, small printers, 3 servers, 9 computers, phone system, and CCTV security system). We use individual APS UPS units for each computer. In my office I like music and use a Bryston B 100DA integrated amp, Bryston BCD-1 CD player, Magnum Dynalab 609T XM Satellite radio, and a pair of Wilson Audio Duette speakers. I tried four different line conditioners and still heard noise (little clicks and some humming) which irritated me to no end. Then finally plugged everything into a Richard Gray's Power Company Isolation Transformer. No noise, and the system has never sounded better. Even my 32" Sony flat panel TV has an improved picture. I don't know if I was experiencing a ground loop problem, or noise from the DC transformers which power all the low voltage task lighting around the office, general EMI, or some other AC problem. I even tried an outlet not protected by the surge suppressor and the noise level was more pronounced. But for some reason the isolation transformer works perfectly; actually so well, that I see no reason to introduce any additional line conditioning.

My point being, solving the mystery of AC generated noise can sometimes be frustrating. It is a matter of tenacity; just keep chipping away until you hit the solution you are satisfied with.

LIZ:

"I use a Furutech E-TP80 and the Almight Omega Mikro Active Plane Power cord! These totally lower the noise floor!"

I am not at all familiar with Omega Mikro products, but I am familiar with your Furutech unit. Unique and wonderful EMI technology, and a well made unit. However, their surge suppressor is Mickey Mouse, and gold plated outlets are almost useless (unless you live in a marine environment or high humidity), and it offers very little to correct for ground loops. But if it works wonders for you, than all the better, you have found the right solution. I should mention that in many urban locations EMI is a major problem.

My friend Dan who resides a 1/4 mile north of me, lives next to a large 12 story condo building. He has a Classe/B&W system and experiences a good deal of EMI problems in addition to major sustained voltage drops enough to effect baking times in the oven. He uses a Furutech unit for his CD players and pre-amp, and is pleased with the results. My suggestion was to exercise his civic duties by joining the town council and start battling with the power company from a position of authority. ;-)

Daphne

Batterys should be perfect power for individual audio components. They can be placed very close to where they are needed, share a ground only with themselves and the circuit they power, and are already DC. No rectification required. Trouble is they usually don't sound as good as well designed switching/linear power supply's. Much of this is because current leaving a battery substrate (like the plates immersed in acid on SLA's) does not do so in an orderly fashion. Additional circuitry is needed to stiffen this current so it can respond to the instant transients that are what music , for example, are all about. Different batterys have different "sounds" to them also, which opens another layer of hell to deal with. Not saying they don't have there place, they do. I only have experience powering small circuits, but can imagine the same problems would remain on a larger scale.

Having said all that a whole house system, solar or wind, that is battery stored DC inverted to AC? If so that would be way above average quality if the proper equipment was spec'd. Way better than the 2 very bad AC power scenarios Daphne described at least. Very glad to have consistent voltage where I live.

There is a lot of battery technology available on the market today. Many advancements were developed during the early 1990s, and with computer circuits, the reliability and ability to store energy has vastly improved. However, there are still hurdles to overcome. The size, weight, and longevity of batteries remains an obstacle for many applications.

Large batteries for home or marine use can be very reliable and deliver power for a week or more. Although, for small mobile devices, the search for adequate battery power continues. One problem with batteries is the charging rate which varies with the type and size of each battery.

The contractor who built my house went way beyond a normal home electrical system and installed a UPS system which includes an APC whole house battery backup system, and a backup generator powered by propane gas from a large underground tank. The system handles everything from simple brownouts to spikes, to a week long power outage. I live on the barrier island where current to my community is supplied by cables running under the Intracoastal Waterway, not to mention regular tropical storms and hurricanes. I have known the current to go on and off five times in less than half an hour, so my backup system works often and quite well. Mostly I experience voltage drops and brownouts which lead to surges. Whole house electrical backup systems with isolation transformers, batteries and DC to AC inverters can clean up the current, but are far more complex than one can imagine and require a good deal of maintenance. The batteries used are for short term standby use.

Alternative energy, like generating power from a wind turbine or solar cells can be just as complicated and even more expensive. To be independent of the public AC power source, one will need the ability to safely store energy when there is no wind or enough sunlight. Therefore the use of deep-cycle batteries are required for sustained power. Designed for a slow discharge rate (high amp hours), they are large and very heavy (once known as traction batteries because they were 8" x 10" on the top but 20" to 30" high and used to power electric fork lifts, installed off the back end for leverage weight). I've seen a number of installations which use several banks of 2 volt batteries (the fewer the internal cells the more efficient the battery). 12 - 2 Volt batteries connected in series = 24 volts; then run parallel with another series. The advantage of deep-cycle batteries is their ability to slowly discharge, quickly charge, and can be repeatedly charged for five or more years.

Most people fear being alone, and not being dependent on the basic public power grid is taking too much of a risk. Wind Turbines and solar cells are used with an inverter and connected to the grid to supplement the incoming AC power. Of course it reduces their electric bill, but offers very little in the way of cleaning up the current.

DC to AC inverters have also improved delivering balanced, pure sine wave power. One can obtain inverters in a variety of sizes and capacities, even units designed to power car stereo amps.

Applying alternate energy sources, for now, is not financially feasible for the sake of audio components. You can purchase line conditioners, or even an expensive UPS pure sine wave unit for far less than batteries, charger, and an inverter which will not necessarily yield clean power.

Daphne