Testing Two
Line Conditioners
Most
audiophiles know that line conditioners can make a difference in how equipment
sounds but it is hard to swap gear quickly when changing the power source for
several components all at once since. For most folks, audio memory fades
quickly and swapping things over – even in less than a minute – can cause this
fading. But with both source material and a playback system capable of
revealing intricate nuances and exploiting strong virtues, things can get a
little easier. The latter is what we hoped to achieve in this evaluation.
The Components
The
names and models of the core components used in this evaluation are shown in
Figure 1 below.
- Synology 1515+ NAS [music source]
- Netgear GSS108T managed network switch
- CAT-8 interconnects
- OPPO UDP-205 streamer
- Furutech FA-220 interconnect
- Onkyo P-3000R preamp
- Furutech FA-220 interconnect
- McIntosh MC2100 power amp
- Hand made star-quad OCC speaker wires, four sets for each channel to each crossover network input
- A pair of hand-made planar speakers [modeled after the Infinity RS-1B]
- Sony XBR-85X850G 4k TV [used as a video monitor only]
 |
| Figure 1 - Core Components and Conditioners |
Except for the TV and CAT-8 cables, none of this core gear
vaguely resembles the original design in that just about everything under the
hood has been upgraded and/or improved in some way. Trying to sort this sound
out with your own knowledge of similar stock quality components is hopeless
since this system sounds nothing like the original gear. However, the goal of
this evaluation does not consider equipment characteristics but rather focuses
only on perceived A/B changes.
The
goal of this test is simple: To compare two Clarus Audio line conditioners
to see if we could notice audible differences between them [see Figure 2].
While conceptually this sounds like a simple thing to do, swapping all of the
components from one source to another while changing only the line
conditioner proved to be more involved than we had hoped. Undoubtably, the best
way to do this would be with some sort of a switch but we felt that this
approach could possibly introduce anomalies that we wanted to avoid.
We
decided on using the cord from the amplifier to plug into one half of a duplex
outlet and a short power strip to the other for the rest of the core gear. In
this way, there were only two plugs to swap when swapping out the line
conditioner thus saving precious time and thereby minimizing potential
audio-memory loss.
We
tested two Claus Audio line conditioners: the Duet and the Concerto. The Clarus
Duet model is a small single-channel duplex outlet passive design using
common-mode filtering while the Concerto uses differential-mode and common-mode
filtering.
 |
| Figure 2 - Duet and Internal Components |
The
much larger Clarus Concerto also uses similar passive filter designs but
has different styles of filtering to each of the duplex outlets. Each duplex
outlet is designed to handle one of the four common types of components found
in a typical home audio system: HC) high current, D2) Digital 2, D1)
Digital 1, and A) Analog [see Figure 3]. This plush model also provides
other features like sequential turn-on for each duplex outlet and a line
voltage display to name a few.
 |
| Figure 3 - Concerto and Internal Components |
Upon
visual inspection, the parts used in the noise-filtering section of the
Concerto HC channel seems quite similar – although not completely identical –
to those used in the Duet. Also note that the two digital channels [D1 &
D2] in the Concerto appear to share the same component design. Lastly, notice
that the HC and A channels appear to be identical in design except for the size
and type of the inductor.
The
power cords used in the test for the line conditioners were provided by the
manufacturers as:
- For the Duet, we used the Clarus Aqua HC 2 two-meter [6’] Power Cord [#CAP-HC-060B, MSRP $860]
- For the Concerto, we used the Clarus Crimson HC two meter [6’] Power Cord [#CCP-HC-060B, MSRP $1,720]
Although
using different power cords technically changed more than one component during
the evaluation, we felt this difference was negligible compared to the
considerably larger differences between their technological designs.
The Data
A
YouTube video about this physical setup can be seen here.
The following test equipment was used during this evaluation:
- Extech 161032-00 Noise Analyzer – used to “hear” and measure the noise on the AC line [in AC millivolts – mV]
- Radio Shack 22-812 DMM – used to measure the Neutral-to-Ground [N-G] voltage of the wall outlet and the conditioned duplex outlets [in AC mV]
Both
line conditioners were plugged into the same wall outlet that measured to be
118VAC. AC Line noise and N-G measurements are listed below.
Here
are the measurements with only one conditioner on at a time [the Duet ON Concerto
OFF when measuring Duet, and vice versa].
Component
|
AC Line Noise
|
AC N-G Voltage
|
AC Outlet
|
>200mV
|
39mV
|
Duet
|
17.5mV
|
186mV
|
Concerto HC
|
16.8mV
|
270mV
|
Concerto D2
|
16.7mV
|
257mV
|
Concerto D1
|
16.6mV
|
261mV
|
Concerto A
|
16.5mV
|
289mV
|
The
measurements were repeated with both units ON and the results shown
below:
Component
|
AC Line Noise
|
AC N-G Voltage
|
AC Outlet
|
>200mV
|
39mV
|
Duet
|
16.9mV
|
276mV
|
Concerto HC
|
17.5mV
|
295mV
|
Concerto D2
|
17.5mV
|
286mV
|
Concerto D1
|
17.5mV
|
287mV
|
Concerto A
|
17.4mV
|
308mV
|
The
measurements were repeated with both units OFF and the results shown
below:
Component
|
AC Line Noise
|
AC N-G Voltage
|
AC Outlet
|
>200mV
|
39mV
|
Duet
|
N/A
|
17.2mV
|
Concerto HC
|
N/A
|
2.7mV
|
Concerto D2
|
N/A
|
2.6mV
|
Concerto D1
|
N/A
|
2.8mV
|
Concerto A
|
N/A
|
2.7mV
|
An
AC line noise measurement tests the ability of the conditioner to eliminate EMI
noise on the AC line from Neutral to Hot. The N-G measurements test the
integrity of the grounding scheme within the conditioner.
The Process
To
aid in quickly swapping out the gear, a three-foot power strip was used to plug
in the low-power devices [the OPPO, the Onkyo, and a television monitor]. Using
the power strip allowed us to quickly move only two plugs from the Duet to the
Concerto thereby saving valuable time.
All
equipment was momentarily turned off during the swap between conditioners, a
process that took less than two minutes.
The
same song was selected on the network server and repeated for each conditioner
tested under as identical conditions as possible. The volume level of the
preamp was never altered during the entire test and every person retained their
seating positions during the swapping of these conditioners. To the best of our
ability, the only thing that changed during this test was the quality of the
power delivered to the core components.
The
following selections were used during this evaluation:
- Mayo Nakano Piano Trio – Scabious, 4k UHD, 24-96 recording
- Lady Gaga & Bradley Cooper at the Academy Awards – Shallow, 720p HD
- Scala & Kolacny Brothers - Nothing Else Matters, 16-44 uncompressed FLAC
- Melody Gardot – Ain't No Sunshine, 16-44 uncompressed FLAC
- Janos Starker – Bach Cello Suite No. 1, DSD64
The Results
There
were four people at this review [Wanda, Bob, Craig, and Brad] plus myself and
my wife. I was seated to the left of the left channel about mid room and Wanda
and my wife sat across from me to the right of the right channel; the other
three folks were seated near the sweet spot. We started the afternoon with all
of the gear plugged into the duplex outlet of the Duet. We then moved to
the Concerto using the HC outlet for the power amp and because of
cable-length issues were forced to use the D2 outlet for the rest of the
gear. We would have preferred to use the A outlet but were unfortunately
unable to do so as constrained by the length of the cords. We did not move
either conditioner during the power-swapping procedure [both remained in the
same physical location on the floor throughout the tests].
Pianos
are probably one of if not the hardest musical instrument to record
properly. The sheer physical size of a concert grand along with its complex
mechanisms make it a worthy instrument to hear when evaluating any playback
system. Of all the pianos made, none sound good for every type of music.
However, my personal favorite is the Bosendorfer because of its rich heavy
overtones, something that makes most other pianos sound literally anemic in
comparison.
Add
to this aforementioned difficulty of a once-in-a-lifetime performance by a
highly-talented pianist and the loss is far more than merely additive. To me,
any performance by any pianist has the potential for reaching that level of
excellence that makes it unequivocally unique and eternally memorable. The
Briphonic recording company has addressed at least the former half of this
issue with their stellar recordings, and the latter half by a small jazz trio
lead by a petite woman named Mayo Nakano. Combined, the listening pleasure is
remarkable and you find yourself listening not only to the amazing
interpretation of the artists but also to the deliberate execution on the
instruments.
This
particular performance is one of those magical times and why I selected it. I
will describe the reactions and opinions for each of the conditioners for each
selection. Our results may surprise you.
The
Duet
This
was the first recording and the first conditioner in our evaluation. This was
therefore the “reference” point from which we familiarized ourselves with the
sound of the playback system. After an appropriate time passed where our panel
of reviewers made mental notes about psycho-acoustic details, we shut down the
system in preparation for switch to the Concerto. No comments were made at this
point since there was nothing to compare its performance to.
The
Concerto
Upon
first hearing, the initial and unanimous reaction was that the Duet actually
sounded better than the Concerto in many ways including image focus and overall
clarity. This surprised me because from my seating position on the left side, I
heard a superior control of the bass with the Concerto. As the music played on,
all of our four-panel members agreed that the Duet was the winner for accuracy
and tonal balance, at least for this selection.
The
Academy Awards Ceremonies often spotlight segments in performances by artists
worthy of consideration to this highly valued prize. Although some compromises
must be made in the recording of such a live venue [here the lid of the
Steinway piano was closed], that magical artistic performance could not and
would not be denied. There is a good reason behind why the Academy selects the
performances they do and much like the Mayo Nakano Trio performance, this one
immediately grabs your attention. As soon as the guitar solo begins backstage
leading into the song, you know from the audience’s enthusiasm, something
memorable is about to happen. These two artists do not disappoint, although
there were passing comments about Bradley Cooper not being a “real” singer by
more than one panel member.
Regardless,
this was a very good video for this portion of the evaluation. So how did they
perform? Read on.
The
Duet
Now with some experience in the sound of the playback
system, more focus was placed on the music, although it was a highly charged
emotional rollercoaster once Lady Gaga started belting out her lines. There was
a comment made that the piano was not well recorded and I added that the lid
had to be closed for the camera crew. With enough information in tow, we
switched over to the Concerto. Again, formal comments were held until we had
time to evaluate both conditioners.
The
Concerto
As
soon as the music wafted through the air, facial expressions abounded from all
of the panel members. I was confused not knowing which piece of gear was
preferred. After some debate, again the Duet edged out the Concerto but this
time not by much. There seemed to be less of a difference noted between the
two, at least for this selection, and the normal comments about sound stage
size and image focus were graded about the same.
However,
after further discussion, we realized that the addition of a visual image
biased this opinion so we stopped this form of evaluation and moved on to
audio-only sources.
A
few of us heard this piece at the large MBL speaker demo in Sarasota way back
in January, 2020, long before the COVID-19 constraints. The MBLs created a
totally convincing sound stage at almost any seating position due to their
unique omnidirectional design. It was this deep and wide sound stage
transformation that easily showed changes when moving from the Duet to the
Concerto.
The
Duet
The
Duet sounded quite good with a life-like representation of the sound stage and
good clarity and focus. The overall width extended to roughly the outer edges
of the speakers and the height to just below the wall-to-ceiling boundary. The
depth was also quite good although the overall impression was that the
psycho-acoustic image seemed a little compressed.
While
an adequate representation of the chorus was recreated, final judgement was
deferred until we gave similar time to the Concerto. As with the other
selections, the system was turned off and the Concerto switched on in under two
minutes time.
The
Concerto
A
quick change to the Concerto and I could see in the panel’s eyes that this was
a big change. Compared to the Duet, the sound stage size of the Concerto was
larger extending beyond the outside boundaries of the left and right speakers.
The front-to-back depth was enhanced and the reverberation in the far corners
was more easily revealed. The biggest difference noted was in the inner
detailing of the individual performers with clear enunciations in words and
timing differences in delivery far more pronounced.
One
individual noted that the piano notes appeared more prominent and natural
sounding and the bass was even a little tighter, a surprising for only a change
of a line-conditioning source. With the performance at its end, more comments
were made about the improved focus and clarity compared to the Duet.
It
appeared that the favored conditioner for this selection was easily heard to be
the Concerto. There were curious suggestions speculated as to why this was
possible, but no conclusion formulated.
The
next piece would help clarify this quandary.
There
are two versions of this album: the domestic single-CD and the import dual-CD.
This song appears only on the imported version and this particular live
recording is impressive capturing not only a golden voice but also an
emotionally charged performance, something elusive verging on unique.
I
heard this recording at an SAS meeting years ago and was immediately drawn to
its alluring synergy. Not only was the band performing at those extreme levels
but also completely anticipating the vocal character of this outstanding female
vocalist. The delivery is jaw dropping in all regards.
The
Duet
The
performance begins with audience applause that reveals a lot about the concert
hall. The Duet did a fine job at showing how spacious this venue was and the
mix of instruments tastefully done so as not to overpower the star of the
selection, Melody’s liquid voice.
The
Duet masterfully showed her command of the jazz style even revealing hints at
wind noises in her throat during breaths at pauses. This conditioner truly put
a little magic into the air so without further ado, we switched to the
Concerto.
The
Concerto
Once
the applause filled the air, there was an immediate expansion of the sound
stage in all directions. It was much like turning up the volume on a
performance to hear the background nuances – but without turning up the volume.
The bass was considerably tighter with details of string resonances expounded
while still featuring and not overpowering the vocals. Smiles turned into grins
as the serious expressions of listening focus turned into delight. It was easy
to hear why this unit costs so much.
Again,
we discussed why this could be and decided on listening to more before
finalizing any opinions.
This
track is a solo cello performance from the old Mercury Living Presence label,
originally recorded in September of 1965 and reissued in 2014 in DSD format.
Starker’s virtuosity is never in doubt and it is all brought to the aid of the
music, and the superb Mercury recording captures every nuance of the soloist’s
playing. This particular performance is a favorite of mine since the care these
old engineers took in preserving realism is remarkable considering its age.
The
Duet
The
recording begins with a distinct pause where one can hear the air conditioning
system slowly swirling in the background. As Janos begins, you can hear the bow
momentarily rest on the strings before his movement begins to excite them. The
clarity the Duet allowed the system to reveal was impressive considering that
everything was only running through one channel of filtering. As the music
continued, more and more nuances about the cello itself were revealed and you
could imagine it swaying under the caress of this master’s whims.
After
a brief discussion, the panel was excited for hearing this piece through the
multi-channel filtering of the Concerto. In less than two minutes, the sound
returned.
The
Concerto
Again,
the air conditioning whirs could initially be heard but this time with even
greater resolution. You could tell that the system was deliberately
sound-damped so as to muffle the otherwise intrusive sound of the blower
motors, a level of detail right down at the level of the noise floor. It was
impressive.
When
Janos made the cello sing, there was an air of emotion conveyed that was not
present with the Duet. Other reviewers refer to this as the blackness of a
system and the Concerto indeed cleaned up the low-level noise. Again, the size
of the sound stage blossomed with reverberations reaching to and returning from
the furthest corners of concert hall. Echoes lingered longer and the
front-to-back depth of the recording came alive. There is nothing more
enjoyable for an audiophile than to hear an excellent recording of an equally
excellent performance played as if one were standing near the microphones
listening to it live.
The Summary
Evaluating
two pieces of equipment against each other when the sonic differences are
subtle can be a challenge to describe their own unique contributions at
improving your listening enjoyment. Many reviewers struggle to explain these
minute nuances creating new words to share their emotions. Fortunately, these
two conditioners will not require the creation of new words or the difficulty
in describing their individual accolades. They sounded dramatically different
but yet they both sounded dramatically impressive.
The
best of the best systems can recreate life-like realism, and with enough help
even those not in that high-end category can hint at what is possible. Here,
the Concerto allowed everyone in the room to more fully appreciate the nuances
in any of the recordings we screened, the clear winner of the two. But the Duet
did a fine job considering its price point and something worthy of serious
evaluation.
Visual
distractions can and do interfere with sonic appreciation which is why some
people prefer headphones over speakers. But on quiet evenings when the traffic
fades into the noise floor and all is quiet in the house, either of these
conditioners could give your system a boost. Making music go loud is one way to
appreciate your system but hearing those tiny subtle things in any performance
is something completely different regardless of loudness. The “silence between
the notes” tells you a little about how a performer interprets a piece simply
by the amount of time taken to hear the instruments nuances and allow its tones
fade away. Some say there is more revealed at these times than when other
sounds are heard – the sound in the blackness.
It
was unanimously agreed that line conditioners can make a difference in the way
a system sounds, something a few of the panel members were not expecting to
hear, and yes something some folks disbelieve. The entire panel could easily
hear differences between these line conditioners and that says something in
itself. Although not a double-blind test as some would prefer to have it, there
was no vested interest in either model and no information about their cost
until after the end of the session [another subliminal factor influencing one’s
opinion].
Etc.
There
was no incentive for anyone to favor one piece of gear over the other. The two
conditioners and their power cords were on loan and there was no incentive
financial or otherwise to say supportive or derogatory things about either
piece. We expressed our honest, unrehearsed, and unbiased opinions without any
peer pressure in either direction. We focused on the changing sound rather than
on the equipment involved. Although this is not a scientific or double-blind
analysis, we attempted to make credible judgements based on the
conditions.
Your
conclusions with your equipment may vary, as there is always a possibility for
some distinct interactions and synergy between core components in any playback
system. In other words, these are our findings for this equipment only.
Post Script
A
few days after this evaluation, I hooked up the Concerto to these same core
components, this time without the thought of swapping and without using the
three-foot power strip. I just wanted to hear what the full impact of this
conditioner had upon our system and plugged these components into the following
outlets:
Concerto Outlet
|
Component
|
HC
|
MC2100 Power Amp
|
D1
|
Sony XBR-85X850G 4k TV
|
D2
|
OPPO UDP-205 Streamer/DAC
|
A
|
Onkyo P-3000R Preamp
|
There
are two additional pieces of line conditioning equipment we normally use in our
system: 1) an APC S20BLK pure sine wave regenerator/UPS and 2) a hand-built
esoteric DC Blocker. And of course, the APC is no different than the other gear
with its own set of modifications and upgrades.
 |
| Figure 4 - The S20BLK Undergoing Surgery |
This
is the reference power source and one that is already quite clean. The goal
from this post script evaluation was to determine what differences there were
between this reference system and the Concerto. This evaluation will not be as
scientific in its approach as it was with the other. Here we will listen and
watch the same reference music and videos but not switch back and forth between
the APC and the Concerto.
The
Concerto performed quite well with this massive piano bring out some extremely
lush lower midrange detail. The dynamics were very good and the tonal balance
shifted a bit akin to that of what most folks call “tube sound.” There was a
definite difference in the acoustic signature of the system with the Concerto,
one that took a while for us to adjust to.
The
video quality was excellent thereby indicating that the D1 filtering of the
Sony TV and D2 filtering of the OPPO was spot on. There were no perceivable
differences in color, saturation, or dynamics during any part of this piece.
After
this performance, we were both still undecided as to how to characterize the
sound of the Concerto so we moved on to the next video without much notation
other than what was already described.
Again,
the video quality was stellar. As the scene opens and the camera pans from the
guitarist to the audience, the house flood lights are seen in the top of the
frame and without proper filtering these lights appear glaring and fat bleeding
mercilessly into the surrounding objects. With the Concerto, the bleeding was
well controlled and images precise. Further into the piece one could clearly
see the beautiful wood grain on the Steinway piano.
The
audio quality exhibited the same characteristic as before with the sound
leading toward a warm side. The guitar body and lower string resonances were
quite pronounced and enjoyable with an intricacy that helped you imagine what
the strings may have felt like under your own fingers.
This
was a pleasant experience and so we moved on to the reference audio tracks.
The
size of the sound stage was good with its width appearing at the outer edges of
the speakers. The depth was also good clearly layering the position of the
choral against that of the piano. The accuracy of the vocals was impressive
with the alto’s enunciation quite clear and distinct.
The
sound still leaned toward the softer side making the performance a more
realistic and laid-back experience like being in the 10th row
instead of in-your-face as I have heard some other systems recreate this
performance.
This
piece is where we heard the major differences between our reference power
source and that of the Concerto. With the Concerto, the bass intro seemed thin
and diminished but Melody’s voice was correct. The other difference noted was
the high-frequency content of the applause – that being softened again much
like when heard through some tube systems.
We
were surprised as to how this impacted the depth of the sound stage where the
Concerto did not reveal the full size of this large venue. Instead, it seemed
small and constrained as if the top octave was diminished.
The
characteristic signature of the Concerto continued with this performance as
with all others. There was a definite warmth and silkiness to the sound of the
cello and the body could clearly be heard properly resonating during louder
bowed passages. There was an almost magnetic appeal that attracted you to the
instrument through the entire performance allowing you to focus on how
intensely the bow was pushed/pulled and how the strings responded. This too was
quite pleasing to us and we both agreed it was a virtue not heard in other
conditioners in a similar price range.
While
the depth of the sound stage was good, it still lacked capturing the glimmer of
those distant echoes in the far corners of the concert hall. There was also
some loss of detail in the upper resonances of the instrument itself making it
appear physically smaller than it is in life.
Measurements
After
turning off the system and removing the Concerto from it, we made some
stand-alone noise measurements as shown in Figures 5-7. What we wanted to know
is how well the HC duplex outlet was isolated from the noise generated by
equipment plugged into the D2 outlet.
We
used a 15-foot long string of LED lights powered with a typical 12 Volt 2 Amp
switching power supply [aka wall-wart] as a noise source.
As
you can see for yourself, the Concerto performed quite well handily shielding
noise interference between its duplex outlets. If there is noise suspected to
be generated by another piece of gear in your system, plugging that gear into
its own duplex outlet should totally minimize the problem.
 |
| Figure 5 - Native Line Noise at HC Outlet |
 |
| Figure 6 - Noise from D2 at HC Outlet |
 |
| Figure 7 - Noise from HC at HC Outlet |
Note that these measurements were taken on a different day
than all other measurements and the amount of Native line noise increased from
2.1mV to 15.8mV. It is normal for such fluctuations to exist not only from
day-to-day but also from hour-to-hour.
Conclusions
In this last round of tests, the Concerto performed very
well, especially in its stellar ability to reject noise sources coming from
equipment plugged into another one of its own duplex outlets. The sound
tailored by these line conditioners leans toward the warmer side and less to
the analytical side meaning that equipment matching can cure not only power
line noise but also contour sound from otherwise thin, sterile, or
bloaty-sounding gear.
When comparing your results in your gear to these, you will
undoubtably experience similar matching issue as you most likely have already
when swapping in a new preamp, DAC, or power amp. Once proper synergy is
achieved between all of your gear, your system can come alive like never
before.
I would seriously consider you auditioning either of these
fine products in your system to see if this acoustic synergy can be achieved.
The both products do a fine job at what they are designed to do at a price
point that makes them even more attractive than their competition.
Contact
Information
I
would like to thank Joe Perfito of Clarus Audio for the kind loan of this
equipment. Without his unconditional support, this review would not have been
possible.
I
have received zero compensation for this review other than a pre-paid return
shipper for all of this equipment.
For
more information about these or other of this company's fine products, here is
their contact information:
Gordon J. Gow Technologies. Inc.
6448 Pinecastle Blvd #101
Orlando, FL 32809 USA
888-713-7333 / 407-447-2277 voice
6448 Pinecastle Blvd #101
Orlando, FL 32809 USA
888-713-7333 / 407-447-2277 voice
800-553-1366 / 407-855-2482 fax
www.tributariescable.com
www.tributariescable.com
Yours for higher fidelity,
Phil
7-16-2020
