August 2009

World Premiere!
Audiolics Anonymous Chapter 118
World Premiere Of The adeptResponse aR2T Power Conditioner
Article By Dr. Bill Gaw

  It is the end of June as I write this, a time when most audiophiles have almost completely abandoned their systems for the "great out-of-doors". Even I've been doing yard work, forsaking at least some of my reviewing time for the wonders of nature (and the mowing of the lawn.) On the other hand, I have been drawn back into my listening (and viewing) by the latest iteration of what I consider to be the best power conditioner that has graced my system, from John McDonald who is President of Audience and Roger Sheker who is the design engineer.

This past Friday Maurice Schmir, an audiophile friend and owner of Dyana Audio, invited me up to his house-studio for a listening session along with a magazine reviewer. He had also invited David Nudelman, district sales manager for Pioneer Electronics. Maurice is a distributor and dealer for the Pioneer TAD speakers, the penultimate speaker design of Andrew Jones who is one of the world's best audio engineers. Andrew and his team have also been designing several significantly lower priced ( less than the TAD's $60,000) speakers using similar cones, cabinet materials and crossover parts to their big brother.

David brought along two of their mid-priced line to evaluate, and wasn't the least bit reluctant to put them up against the TADs in direct comparison. While their TAD S2-EX units with stands at $7200 per pair sounded superb and certainly gave the big TADs a run for their money using the same equipment (Acuphase electronics and Nordost Odin top of the line interconnect and speaker wire) what amazed the three of us were a pair of $1900 each Pioneer S-1W891in-the-wall speakers that David had mounted on a 2 x 4 foot enclosure mimicking the standard home wall with 2 x 4 studs and wall board. This was the first demonstration of in-wall speakers I've heard that didn't drive me from the room. They were quick, with a very clean mid-range and bass down to about 40 Hz. Their only major deficiency was a flattish soundstage. Of course they were being drive by somewhat more than $100,000 of equipment and wire, and were no match for the other Pioneers and TADs, but certainly acquitted themselves superbly for their purpose.

As you can gather from many of my previous articles, my area must have some of the worst electricity in the country as far as noise on the AC lines is concerned. Thus, a large portion of my audio experimentation has been to try to eliminate this problem, as the best equipment cannot work to its fullest potential if crap electricity is being fed to it. You will have to go back and read about 20 of my previous articles to get an idea what we've had to do to correct the problem, but the best fix up until now has been the following:

a. Two APC S-15 Power Conditioners feeding the front two channels.

b. Two APC H-15 Power Conditioners for the rear channels and video equipment.

c. One adeptResponse aR1 power conditioner driving the rear channel APC H-15 unit.

d. Each of the APC S-15 units powers a Bryston Torus 15 amp Power Isolation Unit which feeds the front amplifiers. These use massive torroid transformers for further noise isolation and at the same time and with its low source impedance and current storage removes current limiting as a problem.

e. One of the Apc-S15 units also powers an Audience adeptResponse aR12 high resolution Power Conditioner which feeds all of the source components and preamplifiers.

This ganging of conditioning units multiplies their ability to remove unwanted AC noise just as a second or third order crossover has steeper curves for blocking out more of the out of band frequencies. The negative to this is that ganging of the units can lead to current limiting by affecting the phase of the voltage and amperage waves; thus the use of the Torus units, whose transformer stores current for needed surges. Compared to electricity straight from the grid, the system is significantly quieter allowing a much lower noise floor. This allows a cleaner presentation of the ambiance information, tighter bass, sweeter highs, and the ability to listen at relatively normal to concert hall volume levels rather than the usual 110 dB climaxes that are destroying our ears.

Audience aR2T Power Conditioner
I have previously reviewed several Audience products including their aR1 (click here) and aR6 and aR12 units (click here), plus I still have the aR1 actively conditioning my rear channels and the aR12 on my source equipment. Unhappily, I had to return the aR6 as I couldn't afford it at the time, and the 12 couldn't quite handle the 30 plus amps necessary to condition the whole system. Thus, the two APC S-15 and Bryston units have been used for conditioners for the amplifiers. This setup  had completely satisfied me that the AC filtration had been maximized with minimal deleterious effect. Then I made the mistake of hearing about their newest iteration using their Teflon capacitors, and immediately contacted John for a review unit. A big mistake for my wellbeing… and that of my bank account.

Anyway, they sent their newest product, the aR2T with two outlets. Considering that my system uses 6 amplifiers for just the two front channels, I had a difficult time deciding where to place the unit for the best evaluation of its new circuitry and the difference between the regular and Teflon caps. The unit's chassis is similar to the others in their product range, coming in either silver or black. They also include one of their E-type power cords, as the unit uses a special  PowerCon  30 amp 250 volt locking plug. I guarantee you'll never have to worry about this cord dislodging from the unit. It has two 20 amp Hubbell high conductivity AC receptacles which are completely isolated from each other, sort of a dual mono configuration.

Their new AU24 powerCord with OHNO mono-crystal copper wire can also be purchased with the unit for normally $2200 extra but is now on sale for $1550. Supposedly it works even better than the E cable to improve the AC noise floor, but I haven't had a chance to try it. Also I couldn't try any of my other specialty AC cords with the unit due to its locking plug.

There are two levels of quality to the aR2 units, with the standard unit using Auricap High Resolution capacitors while the one they shipped here for review uses their Aura-T Ultra High Resolution Capacitors. Both types of capacitors can be bought separately to be placed in stock components, with the Teflon caps being about five times more expensive than the standards. Considering that the aR2 costs is $2100 and the T is normally $4200 but can be bought now for a special price of $3900, the T is a theoretical better-buy if it functions at a higher level. From the information gathered, the unit was designed for high amperage situations and two pieces of equipment located a distance from the other units, such as high wattage amplifiers. According to Mr. McDonald, unlike the larger units, it doesn't require a separate buss bar, has a new ground plane and a slower acting circuit breaker. This allows it to take large surges to amplifiers without popping the circuit breaker.

I have long been a proponent of the use of Teflon capacitors for certain high end applications. They have the lowest Dielectric Constant of any plastic material, and their Dissipation Factor is low right up into the gigahertz range. Thus they are the perfect dielectric for applications where one wants pure high frequencies without smearing of transients and clarity of harmonics. I don't understand how they work so well to suppress RFI as well as do some power factor correction and compensation, as the whole concept of cleaning up AC is to get rid of the high frequency junk riding along with the 60 Hz. wave. Mr. McDonald stated the following:

Teflon is the best dielectric and does not store energy; therefore energy passes through it easier without any time smear that is found in most other non-Teflon capacitors. Harry Pearson of The Absolute Sound talked about this quality in his review of the aR-T in TAS Nov. '08.

So let us get down to the experiments and listening. The aR2T was plugged into the wall using its PowerCon cable, replacing the two APC S-15 power conditioners, using each outlet  running into the two Bryston units, and out to the amplifiers. The aR12 was plugged into the wall with its AC cord with all of the source equipment attached to it. As with all experimentation with AC, each time one changes something, grounding problems can occur. This can be due to potential differences between the various chassis or even using more than one wall outlet. Even if there is a slight potential difference between the negative pin and the ground, sometimes due to even a slight corroding of one, 60 or 120 Hz. hum can reveal itself. This can drive one crazy trying to figure out which piece of equipment is the cause. It would be great for your system if you could eliminate all except one ground to the system, but of course this is against all electrical codes.

Thus, I was not surprised when the amps clicked on again, to hear a small amount of new 60 Hz. hum which was finally isolated to the Integra 9.8 pre-pro. Somehow by removing the APC S-15 from the system, a grounding problem with the unit popped up. After some experimentation, by isolating the pre-pro's ground pin with a cheater, and reversing positive and negative pin, the majority of the hum disappeared. Except for the slight hum, there was a significant decrease in background hiss to the system running the 12 and 2T in parallel. It amazes me the amount of random electrical noise all of our systems allow through that we take for granted, sort of like the turntable rumble and tape hiss so prevalent years ago, which we could easily listen through. I guess it's not surprising as at a live classical music concert there is always significant audience and heating system noise which makes for part of the live experience, that we can listen through (except for the guy playing with candy wrappers directly behind your seat).

After further experimentation, the remainder of the hum was defeated by running the aR12 from one of the Bryston units, thus through the aR2T rather than directly from the wall. Not only that, but the room was dead quiet even with every piece of audio equipment turned on.

Now I know that with this setup, the aR2T and the aR12 were running in series rather than parallel, and this probably allowed the two units to work in synergy to decrease the AC noise sort of like a second order crossover compared to a first. On the other hand, ganging two units in series also should add or multiply their side effects, such as slowing down of transients and loose bass. But that appeared not to be so with these units. I could hear none of the negative side effects usually present with power conditioning, and removing the APC units and adding the aR2T seemed to actually improve transients and bass reproduction. I have to say that once I had figured out all of the grounding problems, the system was the quietest that it's ever been. While I've stated in the past that the system was silent, one cannot contemplate any further decrease in the background noise unless one actually hears it. It always amazes me when a further decrease in electrical junk leads to further delineation of the soundstage, ambiance, and a more musical presentation.

Unhappily, I don't have the standard aR2 here to compare to the T, and with the complexity of my system there is no way of running the aR2T without using the aR12 along with it. All I can say is that the combination of the two with my Bryston Torus units has given me the best isolation from AC grunge that my system has had in over 25 years.

Mr. McDonald was kind enough to send the unit for review about three months ago, and the agreement was that I would complete the review in two months, but was reticent to do so; primarily because this damn unit has put me in a bind. I could not take it out of my system and be happy with the sound, and until now couldn't afford to buy it as my income had dropped precipitously. Happily, He appears to have forgotten about me as I have not received any emails from him requesting the unit back and I'll be damned if he'll receive a reminder from me. Let him come across the country and get it. (Only kidding Mr. McDonald)!! My check will be in the mail for the unit.