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Audio Research PH7 Review
by James Leahy
Introduction
The Audio Research PH7 is the new flagship
Phono Stage from Audio Research. Cut from the same magic cloth as the much
acclaimed REF3 Line Stage. The technological advancement that has
made the REF3 a worldwide legend in sound quality is now carried
right through their entire product range.
Built without compromise, the PH7 comes
complete with full valve power rectification comprising of
three 6H30 tubes and uses an all-vacuum-tube audio stage with four
6922 twin triodes.
This fantastic new design features the best
of everything and provides customers with the best sounding Phono
Stage that Audio Research know how to make with over 30 years of
experience in making some of the best phono circuits in the
world since 1977.
Designed with a hot new fluorescent display
to show all important functions like Mute, loading (47K, 1K, 500,
200, 100 ohms), Stereo/Mono as well as accumulated hours of
operation the PH7 is a winner in the simplicity stakes as well
as a brilliant performer in the sonic department. All functions can
now be fully controlled via the included remote also. Nothing beats
a remote control Phono Stage, thank you very much Bill.
The total gain for the PH7 is factory set
to 57.5dB which as Audio Research claim is more than sufficient for
even low output MC cartridges. I can attest to this claim personally
as I am running an Ortofon Jubilee with output of only 0.340mV.
While this is not the lowest output MC cartridge on the market it is
certainly getting down pretty low and there
is still plenty of gain left on my REF3 Line Stage when this
combination is in use.
To understand why a good phono stage is so
important for those that do not know or have not already experienced
the benefits please read this,
'What's The
Most Neglected Component in a Phono System?'
The super clean design lines of the PH7 make this
model a very attractive unit and a guaranteed future classic.
Rebuilt from the ground up, circuit board
material, power transformer design and size, and other components have
been exactingly selected to boost phono performance to a previously
unachievable level. The PH7 is a very polished performer that will not
fail to bring out the very best that your phono system can deliver.
Even with her skirt off she looks totally
stunning, year after year. Timeless beauty that is appreciated by all
that dare to stare at the formidable PH7. Get down to business without
the mind games with the most amazing Phono Stage I have ever had the
pleasure of using.
The PH7 is no exception to the rule of legendary
workmanship that has given Audio Research a worldwide reputation for
over 37 years of making no compromise state-of-the-art Hi-Fi products
that are simply 'THE' best in their class, regardless of price. If only
all things in life could be created with all the care & attention that
Audio Research bestow on their products the world would very different
place.
The PH7 is loaded with a large array of Nichicon
power-supply capacitors for it's energy storage needs that runs to more
than three times the energy capacity of the PH5. This increase can be
truly felt when comparing the two units. The PH7 is harder hitting with
a massively more powerfull and fuller sounding bottom end that never drains or slows
in even the most demanding musical works.
Regulation of the power supply is also
vacuum-tube, using three 6H30 triodes. Just the way God intended.
Output coupling caps are the costly, advanced
types proprietary to Audio Research that were first developed for the
REF3. Also on display is the all-vacuum-tube audio stage with four 6922
twin triodes.
Sonic
Evaluations
Having been running the award winning Audio
Research PH5 Phono Stage in my system for a number for a months I
though it would be relevant and most interesting for potential
buyers to see a comparison between the two units and see what
differences could be found. Being very used to the PH5's excellent
level of performance the PH7 would have to do a great number of
things significantly better for me to recommend the extra cost at
more than twice the price of it's baby brother.
Taking the PH7 straight out of the box I
installed the tubes and ran through the usual system checks and
allowed sufficient warm up time for the Phono Stage to bring itself
up to it's full operating temperature.
From my experience having tested many brand
new Audio Research products direct from the factory; I am yet to
find one that needs hours upon hours of pre-listening "Burn-In" time
to sound right. This statement may fly directly in the face
of accepted Audiophile public opinion but sometimes I am convinced
that it is the customer's ears that need to burn themselves into
getting used to how a product sounds not the other way around.
Connecting the PH7 directly to the Audio
Research REF3 and REF600 Mk.II amplifiers the anticipation was
intense as I sat down to listen to Dillards - "Roots and Branches"
album (Anthem Records, 1972). Audio Research's 2007 top of the line
frontend for vinyl was about to be unleashed on my system for the first time.
Now there could be no excuse for an under performing frontend.
Having taken years to become happy with my source that comprises of
a Rega P7 and Ortofon Jubilee M.C. I wanted to extract the last
ounce of performance from what I knew were excellent components.
Right off the bat, if you like your bass tight and fast the PH7
will certainly not disappoint. It give loads of low
frequency slam and grunt that is without bloating but at the same
time tremendously powerful. It is quite an improvement over the
previous A.R.C. Reference Phono Stage that was criticized by some as
a touch soft and mushy and without a transparently neutral flavor.
The PH5 generally does well in this area in comparison but fails to
fully extract the lower octaves as easily and comes a distant second
place in terms of overall quality to the PH7. The PH7's superiority in outright bass
authority is unquestioned and this is a very important category to
me when evaluating a Phono Stage. It is many times easier and
cheaper to get adequate to great bass performance from a digital
source then it is from an analogue system but when you get the
combination right with a phono system the results are magnified ten
fold and the effort is well worth the pain.
I am sure the PH7 is helped considerably in
the bass department by it's massive power supply that is
three times greater then the smaller PH5 and the benefit
of makes itself more and more obvious the longer one listens to all
their favorite tracks at all volume levels. The hard hitting deeply
penetrating and solid bass of the PH7 when paired with a high
quality line stage is simply magnificent. You would honestly never
want to go back to digital again after you hear what can be achieved
with a well set-up Phono Stage and M.C. cartridge.
For vinyl enthusiasts the width and depth of
the soundstage is a critical factor often determining a make or
break deal when it comes to different models. The most outstanding
feature of the PH7 is that the sound absolutely just balloons like an
atomic blast in a 360° radius giving a previously unobtainable width
to what can only be described as an industrial reinforced concrete
wall of sound that fills the listening area without any empty
pockets of nothingness. This of course is what is most commonly
desired but let me tell you very rarely achieved in the real world
of Phono Stages. Thick and powerful is the sound with extending
detail in all the different layers. The PH5 does a great job with the soundstage
dimension too and it is totally believable and far surpasses any CD
Player I have heard in comparison. Even amongst other great Phono
Stages on the market I would not hesitate in using it in my system.
The performance increase of the PH5 over the previous generation PH3
was mind-blowing and now through extensive research & development
achieved in the creation of the REF3, the PH7 eclipses the PH5 by
the same margin if not slightly more!
Finally the measure of tonal accuracy and
dynamics should be discussed as a whole and not merely a separate
category. The PH7 is not overly warm or laid back but exhibits the
same sonic qualities of the REF3. For my tastes this is a perfect
combination and one that would suit most systems very easily. Being
designed with a very neutral tone that is neither harsh nor too
forward sounding when listened to at higher volume levels the PH7
gives the listener the very best of what can be hoped for in any
Phono Stage I have heard.
When you have a separate Phono Stage in your system you cannot be
just listening to the tone of the instruments or the size of the
soundstage if there is no bass extension or equally if there is no
synergy with the blending of the final sound that your loudspeakers
produce.
The PH7's great strength of getting the
finest details from even the most difficult recordings and turning
them onto a full 24bit Technicolor work of art is awe-inspiring. By
pairing the PH7 to a highend M.C. cartridge you will have dynamics
to burn. This is critical to get the best M.C. cartridge you can
afford when using the PH7. Do not skim in this area or the PH7 will be ruthless in
showing up any deficiencies. I expect that most PH7 owners will be
running a cartridge of high performance with this unit so this
should not be a problem. The PH7 really brings all the smoothness
from your records out into the air that can sometimes sound dry and
gritty on cheaper units. The gradients of sound are so fine and the
palette of color so grand it makes it hard to go back to anything
else after hearing what the PH7 can do. This is the price you must
be prepared to pay for listening to one of the best Phono Stages in
the world; sometimes ignorance is bliss. You have all be warned!
Having the Phono Stage fully
complement the rest of your system is one of, if not the most important
factors. Using a very transparent Reference system to evaluate new
products on I am blessed with a relatively easy job. It makes the
differences very obvious. The overall
improvement over the PH5 is greatly more significant in terms of the
whole finished package rather than the sum of all the differences for each
category. Meaning in simple language, I could be very happy with the
PH5 if I had a particular budget to work within but having a
substantial Phono system myself I would not have to um and arhhh or
think twice about buying the PH7 over the PH5 after testing both.
The PH7 and PH5 will no doubt suit two very different customers so
their unique individual categories would never endanger each others
appeal. If you
are seriously into vinyl and insist on getting the best possible
performance from your system look no further than the PH7, I know I
won't be. The Ph5 is good but the PH7 is a whole lot better, given
the right system to go with it.
Is the PH7 worth so much more then it's
smaller brother? Is the PH7's performance more than twice as good as
the already great PH5? I feel if you have to ask this question in
order to quantify your purchases dollar for dollar by plotting the
results on a graph to calculate the intersection point with either a
pass or fail, then you would not greatly benefit from my answer.
Associated review Equipment
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Amplifiers:
Audio Research REF600 Mk.II
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Line Stage:
Audio Research REF3
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Speakers:
ScanSpeak & Vifa Custom
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Interconnects:
Furutech
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Power Cabels:
Furutech
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Cartridge:
Ortofon MC Jubilee
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Subwoofer:
Velodyne HGS-15
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Turntable:
Rega P7
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