APC H15 Power Conditioner
Published on June 18, 2006
132 Fairgrounds Road
W. Kingston , RI 02892
Power Conditioner rated for 1440 watts continuous and includes: automatic voltage regulation, surge protection, isolated noise filter banks, DC trigger, sequenced on/off, LCD display with customization, overload indicator, removable support feet, detachable 12-gauge 10’ IEC line cord, rack mount ears, 12 total outlets: two delayed high current outlets, two analog outlets, two video outlets and six digital outlets; two F-type coaxial ins and three outs, 15A circuit breaker, system ground post, telephone in and two outs, and stick-on labels for cords; $750,000 lifetime replacement/repair protection policy; let through voltage <40V; up to 12 amp output; coaxial in/out supports 5MHz-1GHz; 5200 total surge joules; 40-100dB EMI/RFI attenuation at 100KHz-30MHz; UL, FCC, and CSA approved; 17” W x 3.75” H x 9.5” D; 16.7 lbs; 2 year warranty.
Clearaudio Emotion w/ Virtuoso Wood cartridge, Bellari VP129 phono preamplifier, Rega Apollo CD player, NAD M3 integrated amplifier, Bowers & Wilkins 805 speakers and stands, Monster HTS3500 power conditioner (for comparison) and Audioquest cabling throughout.
Setup & Explanation
As with many of the power conditioning components available today, there are a few adjustments that can be made to the H15 that allow for system customization. These are: dimmer function, AVR range (Automatic Voltage Regulation), delay time, beeper, and language. There are seven dimmer settings as well as an off setting. There is a normal, wide, and narrow setting for the AVR. In the narrow range, the unit will function with voltage between 102-132 volts and correct to within 5% of 120 volts. The normal range works from 97-139 volts and will correct to 120 volts within 10%. The wide range works from 92-145 volts and corrects within 15% of 120 volts. There is a delay adjustment from 0-12 seconds on the delayed outputs. The beeper only controls the sound when adjustments are being made—there is no sound in normal operation. As for languages, the unit offers English, French, or Spanish.
The “select” button pushed by itself cycles through the input and output voltage, power draw, frequency, and serial number and firmware. Indicators on the front show if wiring is okay (if it doesn’t light then the reason is either missing ground, overloaded neutral, or reversed polarity), if line voltage is within an acceptable amount, filtering is active, line is being boosted to compensate for low voltage, switched outlet on indicator, delay outlets active, line trim indicator if the line is being cut for too much voltage, and overload status indicator.
One issue I had immediately was with the spacing of the electrical outlets on the back. They are very close together, so will not accommodate a typical wall-wart power supply (like that used with the Bellari or some infrared repeater systems). With a simple two-pronged cord I was able to put it underneath the transformer from the other device and still make decent contact, although this wasn’t optimum, but with a three-pronged cord you can forget about it. Also, there are only two analog outlets—hardly enough for anyone with a non-AV system. The phono preamplifier and turntable were all I could connect. I suppose many people don’t have other analog components, but what about a tape deck or a standard preamplifier?
I was sent a PowerPoint presentation on the product that highlights power anomalies that APC’s conditioner correct. It discussed:
• Surges that can cause stress on power supplies;
• Spikes that can cause an audible “pop” from equipment, momentary video distortions, or catastrophic failure;
• Noise interference that can manifest itself as an audible hum or buzz and/or video hum or distortion in the image;
• Brownouts/over-voltage situations that can limit dynamic range, not supply enough current for components to perform properly, cause video distortion, and/or stress power supplies; and
• Blackouts that can cause a recording to be lost or missed, presets to be lost, damage to hard drives or lost data, projection bulb damage, security and home automation systems to become inoperable.
Listening I – Comparisons with Monster HTS3500
Reviewing power conditioners or surge suppressors/protectors can be difficult because you don’t always know if they are doing their job. For instance, it is the absence of certain “problems” that indicate they are working. The only adverse conditions that I witnessed while actually using the device were a power outage and a momentarily interruption of power. None of the components were hurt in any way, so I assume that the unit did its job properly. I don’t have any major appliances or “noisy” equipment on the line to which my AV equipment is connected (it’s dedicated), so it is likely that a “typical” user (who does) may notice more improvements.
On another occasion I noticed that the APC was correcting the power output voltage. It was registering 126 volts in and outputting 120 volts. I decided to measure the voltage a different day just to see if there was a difference. The wall measured 122 +/- .1 volts, the Monster Conditioner measured 121.7 to 122.0 volts, and the APC measured 121.5 to 121.8 volts. On the front of the unit it indicated it was outputting 123 or 124 volts. I have a digital meter and I doubt it is off by two volts, but who knows.
So, without the ability to really introduce lots of noise into the system, I decided to listen to the APC and find out if it made anything sound better, worse, or the same. I don’t get much in the way of video noise in my listening room, so I concentrated on audio tests (after all, this magazine is called “Audiophile Audition.”) Note: video problems that are related to ground loops (i.e. hum bars) cannot often be eliminated by a power conditioner.
I had a Monster power conditioner on hand that also retailed for $400. It doesn’t do any voltage regulation, although my problem is higher than average voltage, not lower (where you might see some performance loss). The Monster claims to be able to protect against all the same power anomalies as the APC does. They look different and have a few feature differences, but are not dissimilar.
The equipment I operated during the testing was probably a bit above the level of quality (and price) that you’d normally use with a $400 conditioner, but it was what I had on hand. The reason I mention this is that in the past I’ve found more improvements wrought with less expensive pieces—probably because they have worse filtering to begin with and are more susceptible to line noise, interference, etc.
I started off the listening with the cut “Days Go By (Acoustic)” from the Dirty Vegas single of the same name. This isn’t an audiophile recording by any means, but manages to sound pretty good nonetheless. Since it’s acoustic there is less issue focusing in on one aspect of the sound making differences between the conditioners more noticeable. I had to go back and forth a few times before hearing much of any difference, but it’s there. The APC takes a little air out of the sound, tones the strings down and makes things mellower—”grayer” as described by an audiophile friend. The Monster had a very slightly brighter sound and tended to add more pop and involvement. Keep in mind that these differences were extremely small.
On a second recording, “Never Going Back Again,” from Fleetwood Mac’s Rumours CD the APC gave the feeling of ease/smoothness (most likely due to a slight alteration in the amount of high frequency content). Why there should be a difference in this region is unknown to me. You’re probably thinking, “…it sounds as if the APC removed some of the grain and therefore it’s doing its job…” This may very well have been the case, but it also seemed to be removing some of the detail that would have made the recording sound more alive. The Monster had more sheen and a slightly more metallic sound. Again, these differences were very slight.
Listening II – Comparisons with no Power Conditioner
All in all the differences between the conditioners wasn’t that big, and most people wouldn’t hear or care about them. If they did, it might not be such a clear cut case of which one was “better.” So, to check myself, I decided to do a comparison between the components plugged into the conditioner and connected directly to the wall. I was expecting to hear an improvement (as I’ve heard in the past) with the components in the conditioner.
I dug up Madonna’s Music and put on “I Deserve It.” What I heard was surprising—the music sounded better with the components plugged directly into the wall. Initially I thought this was due to the wall outlet putting out more voltage, but in fact, there wasn’t a significant difference in voltage and I found this to be the same case with the Monster! The voice seemed more focused and there was more high frequency output (like I’d heard before). It just seemed to be letting through more of the sound while the conditioner sounded as if it was holding the sound back.
I tried the track “You Leave Me Breathless” from John Coltrane’s Traneing In. Direct into the wall offered a bigger presentation (more open) with more dimension to the sound. The Monster appeared to lack the air of the direct connection, while the sound of the APC was ever so slightly veiled and the presentation/performance had reduced energy. My friend preferred the sound with the APC on this track citing the fact that the track was meant to sound mellow and that is what you got from the APC. The problem was that the APC affected the sound in this manner with every recording.
I spent some time playing records in these tests as well. It was much harder to go back and forth and restart/cue the LP up to the right place, so after listening to some of The Fixx, The Eagles, Boz Scaggs, and Jethro Tull I just gave up and went back to CD. The Bellari phono preamplifier uses a vacuum tube and I thought this would be more greatly affected by the power conditioner, but alas, it was not (in my tests). I also discovered one of the best reasons to have a power conditioner in the first place—all those outlets!
Listening III – Source-Only Comparison
I was beginning to think that the power conditioners were limiting the dynamics (or compressing/muffling/muting) the sound from the amplifier. Many people believe that amplifiers should not be plugged into conditioners (but this, of course, offers no protection for them). Some devices I’ve tested in the past did not affect the sound negatively when the amplifier was connected, so I do not make this recommendation as a general rule—you need to try it both ways and understand the drawbacks of both choices. I turned the volume up as loud as I could on “Straight On” from Heart’s Alive in Seattle release, but I was barely using 18% of the power output capability of the APC ~270 VA.
Still, I thought I’d try switching only the CD player and leaving the amplifier connected directly into the wall. The track on hand was “Here Am I” from Donald Byrd’s Byrd in Hand CD. The results were the same as before: There was more edge, a bit more brightness, but the sound was more alive with a greater sense of space and air with the player direct into the wall.
With the equipment under test, neither conditioner offer a significant improvement in audio quality. The reason to get the APC would be the extensive protection offered to your equipment and/or coolness factor. Also, if voltage in your area is low or you suffer from spikes and surges due to appliances coming on then it is likely problems associated with them can be eliminated or reduced dramatically. Video is another area completely. I’ve seen some noise problems reduced with a good power conditioner. Different equipment may have entirely different results so experimentation or reliance on good advice is essential.
It’s hard not to go into an electronics store these days without receiving a recommendation from a salesperson to buy a power conditioner. Usually, it’s very good advice. But, like anything in audio, it’s important to make sure that you purchase something that makes sense and mates well with the rest of the system. This information is not always easy to discover, but my experience with power conditioners suggests that it is worth the time and effort.