Audiolics Anonymous 3
Chapter 3: Unwanted AC Line Noise
Article by Bill Gaw

  Hello Fellow audiolics! Welcome to another meeting of Audiolics Anonymous, our support group for the insatiably TWEAKED. Have you gotten down to 90% tweaking and 10% listening yet, or are you still listening to the same piece of music over and over to optimize your system. Let’s try to get a little more enjoyment out of the hobby beginning now.

Today, I thought we would go on to discuss the next gremlin producing external distortion in our systems, noise coming over the electrical lines. I am sure everyone has experienced the marked improvement in sound that occurs if one listens to their system late at night. In my area, usually sometime between 9 and 11 o’clock, the sound opens up, veils are lifted and the stage solidifies. This improvement is more marked with digital than analog, with a good part of the digital nastiness smoothing out to a more analog-like sound. And the analog becomes almost palpable. The better the system, the more striking this change is, but it can even be  heard on very modest systems. I have even heard the change on clock radios. What is the cause??

Back in the early 80’s, I originally thought it was the system warming up, as I would normally listen for several hours, from 6 to 11 or 12 o’clock, and the sound would improve over the evening, from very grungy at 6 to glorious at 11. Because I thought it was a  warm up phenomenon, I began leaving all of my equipment on all of the time. This certainly made my local electrical carrier very happy with the increase in my electrical bill, but, heh, this was the eighties and who cared how much it cost as long as the sound improved. Then I had a week off from work, and began listening during the day, and found that the sound was okay early morning, was pretty good in the afternoon, and became very poor during the early evening, subsequently improving at night. Interestingly, Sunday afternoons were almost as good as late evenings. Obviously, this was not a warm-up problem. Matter of fact, I found that if I shut the system down for several days, warmed it up for a couple of hours, and listened, that the sound was improved over what I found at the same time of day with the system on for days. This is another phenomenon which we’ll discuss in a later meeting. Thus, I concluded that maybe there was something coming in on the electrical lines that made the difference. So I called up my guru, Clark Johnsen of the Listening Studio, explained what I had heard and deduced, and heard a laugh from the other end. He had been hearing this for years, and had developed several tweaks of his own to combat the situation.

Interestingly enough, just about at that time I made the acquaintance of Nick Venice, of Queens, New York, who had also purchased his equipment from Clark ,and he introduced me to Sal Demicco, of Distech, Inc., who introduced me to George Tice. The two of them had been working on this gremlin for years. It turns out that there are several things going on.

First, current and voltage waves don’t necessarily have to be in phase with each other. Capacitance and inductance changes on the lines and in the house may separate the two in time, so that the AC to DC converters in your equipment do not function optimally.

Second, The 60 Hz. wave is almost never a pure sine wave due to several causes. 1. Each appliance, motor, fluorescent light, dimmer, computer, piece of digital equipment, etc., between you and the power station, is sending spikes along with the wave. 2. The wave received is actually coming from multiple generators, and if they are not in perfect sync., then the wave is distorted. 3. The electric company actually adds radio signals onto the wave both to monitor the system, and actually transmit information for several money making deals they have.

Third, Radio frequency interference (RFI) is picked up from the air by the wires. I like to think of the electrical grid as the largest antenna farm in the world, with every radio signal in existence being picked up by the wire.

Fourth, and my own theory. I think the grid is picking up noise from the sun. I think that is why the system sounds better a couple of hours after sunset. Things go on in the ionosphere after sunset that allow better radio reception, especially in the AM and short wave bands, and I think whatever it is, also cuts down on the grunge carried by the grid. I have never seen this discussed, but I would love to hear from any engineers who have theories as to how the sun could affect noise coming in over the AC.

Now some of this is filtered out  by the transformer out on the street from which your electricity comes, but not all. Sal noted this, and he was the first to try to improve the sound through the use of special electrical cords to shield out some of the noise. Thus the  high end AC wire industry was born . George then began using transformers, inductors and capacitors, for shielding and improvement of the power factor ( the relation of the voltage to the current waves), and thus was born the high end power improving equipment.

I took hints from the above individuals and began experimenting. First with power cords, which made an improvement, but never enough. The best I have found so far are made by NBS, Electraglide, and Synergistic Research, and I am still experimenting. I believe most of them act as first order low pass crossovers, which helps but does not cure. Then I began purchasing 2 and 3 KVA isolation transformers, and adding capacitance in parallel. I found that placing them in series, I would get an improvement in the grunge, and actually at one point had six in series, with several mic. of capacitance, and got improvement, but I could always hear a great difference at night, with just some improvement during the day. Also, the transformers made the system sound sluggish, with decreased bass slam. Plus, having multiple large black transformers out in the open certainly didn’t improve the looks of my room, or the safety of the system.

Next came Red Rollers added to the outside of the interconnects and line cords, and Wood Blocks to the AC cables. A 40 amp service directly to the listening room to isolate it from the rest of the house, also helped, and also improved the slam of the system due to improved current flow. All of the outlets were changed to hospital grade, and each plug had Caig DeoxIT GOLD (formerly ProGold)  applied, to cut down on junction noise. All of the grounds were isolated, all of the chassis were grounded to the preamp, and tied in to an 8 foot copper grounding rod placed just outside the room, which was then run back to the house ground by a separate line, and further attached to a large bore 100 foot long grounding cable buried alongside the house.

I won’t bore you with the weeks and months of experimentation and frustration I went through with only modest results. Finally I got the bright idea: Why don’t I completely isolate the system from the grid and run on batteries. No connection, no noise. Problem though was that all of the equipment still needed AC unless I wanted to produce everything from 5 to 500 volts DC. for the tubes, transistors, and op amps. I first tried a home generator, and got horrible noise as it was putting out a very spiky wave. Next, regular uninterruptible power supplies for computers, which unhappily were primarily noise reduction devices with battery backup which only turned on when the AC went off. Then I came upon MSB, a high end audio company out of California, which made supplies designed for audio. These converted AC into DC, charged batteries, then produced a perfect 60hz. sine wave at a regulated 120 volts. I purchase four of them , hooked the equipment up to them, and listened.  That did the trick. Now, I could listen even at six and get good sound. Interestingly enough, even this still allowed some grunge through,  but now the sound at six was as good as it had previously been at twelve, and at twelve it was glorious. In addition, I found that the amps seemed to have gained some muscle. Turns out the batteries have very little resistance, so that the units could pump out power faster than the house line could supply it. MSB was great with their service, and they even lent a friend of mine a couple of their units at a CES a few years ago, where the power was atrocious. I think he got several dealers for his equipment due to the improved sound from his system from the isolation. Problem was, when I added surround channels and video a couple of years ago,  I found that I needed more power.

Unhappily, MSB had stopped producing the units. I wanted to add some more power to my system, but didn’t know what to do. My savior came in the form of  an article in Wide Screen Review, issue 30,  by Daniel Sweeney who discusses AC power conditioners. He discusses surge protectors, isolation transformers, RFI filters, Line voltage regulators, power factor correctors, and Sine wave regenerators. It has to be the best article I have seen on the topic. Anyway, from this article I found the Toshiba uninterruptible power supplies, and ordered two 2KVA models with built in isolation transformers. I must say that these are even better than the MSB units, and about half the price (about $2000 each.) So now I am running  four MSB 1.5 KVA supplies, one each for the digital equipment, the preamps, phono, crossovers and turntable, one for the video and one for the surround channels, and two Toshiba 2 KVA supplies for the main channel and subwoofer amps.  With this system, the sound is wonderful during the day, and glorious at night, and I find that I can run the system on batteries for about 20 minutes, when I want wonderful sound during the day. Most likely, there is still some grunge coming in over the ground, which can only be relieved by disconnecting from the wall and running on pure batteries. I think my next Tweak will be to buy some deep discharge marine high amp hour batteries and run completely off of them. I’ll let you know the result.

In Issue 33 of Wide Screen Review, there is a second article by Doug Blackburn, discussing lower cost isolation devices, which is very good, and will be continued in the next issue. I’ll be very interested to hear what he has to say on the subject. 

If there are any other  tweakers or AC engineers out there who have any more to ad to this topic, please e-mail me here, and I’ll include your comments in my next article. I admit that I’m only an amateur on the subject and would welcome any more advice.

FLASH

This week , Clark Johnsen of the Listening Studio in Boston, and the Tweaker of all Tweaks, brought over a machine which is going to revolutionize CD playback.

Called the Audiodesk Systeme, from the Glass Reiner company of Germany, it is basically a lathe designed to carve away the edge of a CD to make it true round and balanced. The edge is coated with a black marker, and allowed to dry. The whole exercise takes less than a minute, needs to be done only once, and Oh Boy, what a difference in the sound. This is the first time that I have heard digital sound almost like analog master tapes. The sound was better than what I have heard from the few 24/96 DVD recordings I have from Classics and Chesky.

I trued up everything from Merc. to RCA to Chesky CD’s, and  we listened to both before and after, and I’ll tell you, the difference was not subtle. The best came very close to the sound I get from my $16,000 Walker turntable - Crown Jewel cartridge- Wright phono system. Clark brought it back up this week  to try on my DVD’s to see if there is improvement in video and high bit digital recordings, and low and behold, even AC-3 DVD’s started sounding better, with much less stridency. The picture also improved somewhat, especially on the anamorphic discs. The 24/96 Classic and Chesky DVD’s were as close to digital master tapes as I have heard. We were even able to compare them to 16/44 CD’s I had of the same discs, and the improvement was, again, not subtle. I have used all sorts of tweaks on CD’s, and still use demagnetization, a CD Blacklight disc, ECO and optical enhancer fluids, and this procedure beats them all for improvement, and combined with the above, gives sound approaching the best analog.  Clark will be writing up a technical article on the unit for Positive Feedback magazine, so if you don’t mind waiting for the paper word, pick up the next edition. Otherwise, go out and buy a unit, or call Clark at The Listening Studio, (617) 423-4590, for a trial.  Needless to say, I have decided to purchase one.

Well, that’s it for another meeting. Next month, I’ll most likely continue on with  my trials and tribulations with room reverberation. Until then , KEEP TWEAKING. And please send in any comments with an okay to publish, so I and the readers can hear from the rest of you AUDIOLICS.