Purity One
Review #1
Brief Synopsis About the Reviewer:
Who am I? I am a Physician specializing in Orthopedic Medicine
and Sports Medicine. I was permanently “spoiled” when my Dad
brought me into a high-end audio store at the end of my 2nd
year in Medical School around 1985. Suddenly, my Sansui
Integrated amp, B & O turntable, and Boston Acoustics speakers
just didn’t satisfy me anymore (anybody else been there?). I
got into audio then big-time, but then realized after visiting
many dealers and starting to attend shows while listening very
critically that no speaker I had heard did everything well. I
first met Speaker Designer Albert Von Schweikert in 1986 as I
had bought one of his Vortex Screens and very much admired their
sound. Two years later (1988), I told him my dream to build one
of the best, if not the best, speaker system in the world. Our
project took 5 years at which time we explored every speaker
technology available from plasma drivers, to planars/ribbons, to
electrostatic, to conventional cone driver technology. I
listened intently to every cable, speaker driver, major
audiophile capacitors, inductors, and resistors that I could
find to make sure that we were using the best materials in every
way. The speaker was 4 towers and weighed about 1-ton. The
subwoofer tower was one solid cabinet housing an 18 inch custom
professional woofer driver with transmission line loading and
was about the size of a phone booth except only about 2/3rds as
deep. The “satellite” towers were subdivided into 3 cabinets.
The upper and lower cabinets each contained (2) 11-inch Focal
woofers for the mid and upper bass. The center tower housed a
ribbon super-tweeter, Accuton ceramic tweeter, and (2) 4 ˝ inch
Focal mid-range drivers. The cabinets had 4 layers of materials
with different densities and with special absorbing adhesive
between all 4 layers (constrained layering arrangement) to
entirely cancel any possible cabinet resonance that might
interfere with the driver’s output and to avoid any possible
cabinet colorations. Internal wiring was done with Siltech.
Frequency response was 8 Hz to 100 kHz. Retail price was set at
$65,000.00 for the above speaker system. After 5 years of hard
work (1988 to 1992), it was debuted at the January 2003 Las
Vegas, NV CES and acknowledged verbally to me by every
well-known High-End Reviewer of that day as the best speaker in
the world. However, as I hadn’t “paid my dues” yet, they were
not free to write the same, but Guy Lemcoe did declare it the
Best Sound of the Show. Due to the financing only with my own
means and a severe recession in 1992, I decided to close the
company. However, I gave all the rights to use the technology
developed to Albert Von Schweikert which he used in various
forms in his subsequent models and the Armageddon was eventually
developed into the current VR-11 Von Schweikert Audio model.
I stayed in the back scene for some time,
attending all major shows and every CES in Las Vegas ever
since. About 1 ˝ years ago, I approached Albert again to try
and bring my custom speaker he and I had also designed to be my
personal speaker in 1995 that was much smaller and simpler and
bring the most current technology, crossover design, and
especially the best sounding and cost no object passive
components to place in the crossover. We are nearing the end of
this project and are looking forward to marketing the product
sometime in 2010. I would like to add that I am a music lover
first and audiophile 2nd. If a system doesn’t draw
me into the music and performance, then it just doesn’t hold my
interest long-term. I enjoy attending live performances and I
also play 3 instruments—the trumpet, piano, and guitar.
Search for the “Perfect”
Preamplifier: As a result of the most current speaker
project, I have been on a serious preamplifier quest to help
voice my speaker prototype as I consider the preamp to be
critical to the heart of a reference audio system and have been
diligently searching for over the last year. In fact, I have
listened over the last year to many of the most highly regarded
tube preamp systems most of which are listed below. I will
remark up front that I far prefer tube preamps to solid state
ones in nearly all cases. I enjoy and have used both tube,
hybrid, and solid state amplifiers, but overall prefer a tube
preamp mated to a very good solid state amp in order to gain
advantages that both technologies and sounds offer.
Tube preamplifiers I have extensively
auditioned in the last year:
1) Shindo Monbrison, Masseto, and
Vosne-Romanee Models.
2) Audio Research Reference 3 and 5 Models.
3) Balanced Audio Technology REX Model.
4) Conrad Johnson ACT-II. (Awaiting an Audition of the Conrad
Johnson GAT Linestage Soon).
5) Audio Valve Eklipse and Conductor Models.
6) Allnic L4000 Linestage Model.
7) First Sound Linestage (Presence Deluxe 4.0 Mk II with
Paramount Plus Upgrade)
8) Lamm LL1 Signature Monaural Line Level Preamp and LL2.1 Line
Level Stereo Preamplifier Models.
9) EAR 868 and 912 Preamplifier Models.
10) Purity One Tube Linestage Model with V-Cap Upgrade
The focus of this review will be #10
above—The Purity One Linestage with TFTF V-cap upgrade. Before
I start this review, I would like to congratulate all of the
above tube preamp models and manufactures as every piece is a
jewel in its own right with no major flaws, but each with
various amazing strengths and different “flavors” depending on
the listeners preferences. The Purity One is most deserving to
be in the company of the above august list which I believe to be
some of the finest tube preamplifiers in the world.
Introduction: The Purity One
is the brainchild of Designer Bill Baker, owner of Response
Audio and Bella Extremme. There is one higher model featuring
some balanced inputs and outputs called the Purity One
Reference. The retail price of the Purity One with V-cap
upgrade at the time of the review was --------.
Associated Equipment for Testing:
Amplifiers used to audition the BellaMax Linestage included: 1)
McIntosh 402 Stereo Amplifier (400-Watts into 8-Ohms), 2) Nelson
Pass Aleph-2 Single Ended Class-A Monoblock Amplifiers
(100-Watts into 8-Ohms), 3) Vincent SP331 Hybrid Stereo
Amplifier (150 Watts into 8-Ohms), and 4) Triode Corporation Ltd
of Japan TRV-845SE Model (Integrated Amp with Preamplifier Input
Option, 20 Watts Class-A into 8-Ohms, and Featuring High-End
Carbon Resistors and Mundorf Capacitors). Speakers used: 1)
An Earlier Custom Prototype. 2) B&W XT2 Mini-Monitor Monocoque
Body with JL-Audio Fathom f113. 3) Vienna Acoustics Mozart. 4)
Von Scheikert Unifield 2’s. Sources included: Fanfare FM/AM
Tuner (FTA 100 Model), an Upgrade Company Signature Upgraded
McIntosh MCD-500 CD Player (With Analog Volume Control and
Digital Input), MacBook Pro with Belkin Gold USB Cable into a
Music Streamer Plus Passive DAC Unit for Internet Radio
Streaming and Lossless Ripped CD’s. Sadly, I am without an
Analog Rig—a problem I hope to remedy in the next year.
Interconnect Cables included DNM, Crimson, Synergistic Research
(Precision Reference), Zonotone of Japan (Retail Price of
$1,850.00), and My Own Design (MOD). Speaker Cables included
DNM, Crimson, TARA RSC-1, Zonotone of Japan ($4,400 a pair), and
My Own Design (MOD). All powercords are “MOD” and typically
nearly double the resolution of any component they are plugged
into and to date have never been surpassed by any commercial
cable I have tried against them.
Brief
Physical Description of the Purity One Linestage with V-Cap
Upgrade: The Purity One in possion is surrounded by a
wood front, top and both sides, a bottom Aluminum plate, and the
back is quarter inch black acrylic material. On the front are 3
wooden knobs. The left knob is for the on and off switch, the
middle knob which features a discrete resistor array internally
controls the volume, and the right knob controls the input
selection. On the back, there were (5) pairs of RCA type single
ended input connections and (2) RCA preamplifier output pairs.
There is also a simple 2-way switch on the back for low gain
(10-db) and high gain (16-db) to optimize the gain level
depending on the source chosen (a marvelous feature also found
on the Lamm LL2.1). Since I am not the world’s expert on
identifying various wood types, the following is a description
by Bill Baker of the wood components: “The preamp chassis was
made up of Baltic Birch Ply. The front was 3/4" solid Maple and
then completely covered in Japanese Tamo Ash real wood veneer
with a light custom stain mix.” The unit has 2 tubes in the
driver stage which are both 12AU7’s. My unit was sent with NOS
Mullards which caused an incompatibility with my Vincent Hybrid
Amp (its light was in fast-blink mode and would not play). I
tried some current production Electro-Harmonix which fixed the
incompatibility, but did not give the most optimal sound. I
then placed Amperex NOS Superline Select, vintage early 60’s,
measured and matched by the Tube Master himself, Andy Bouwman
from Vintage Tube Services in Michigan and audio nirvana was
finally achieved. I took a quick peak inside and noted only one
input transformer and all discrete components. The circuit is
said to be a “0 dB negative feedback” and “pure class-A triode
vacuum purest tube-circuit design”. Even the power supply
contains no electrolytic capacitors, but polypropylene with
bypasses. As expected, V-caps were found in abundance in the
gain stage. What features were missing from the BellaMax/Purity
One? No balance control, no mute function, no phase inversion
switch, and no remote with such features as mute, volume
control, and input selection. I understand the newer version of
the Purity One comes with a “fully functional remote control”.
Sound: While I will outline
in more detail the overall sound of the Purity One Linestage,
let me state at the beginning that this is one amazing sounding
linestage and one of the best that I have heard. Because this
unit features the V-cap upgrades, I did intermittent listening
during about 450 hours of break-in time and then serious
listening at the 450 hour mark. My first impressions that
continued upon more extensive listening was of a very fast and
dynamic sounding preamp that initially seems to walk a perfect
line between a “tube” sound and “solid-state” sound with best
bass I have every heard from a tube preamp in terms of pitch
depth, power, and control. The midrange was very palpable with
lots of substance and body to performers, vivid, 3-dimensional,
with just the right touch of natural sounding midrange warmth.
The highs were very fast, open, transparent, and airy with just
a amount of natural sweetness that I hear in live music. In
fact, more extended listening reveals that the unit doesn’t
sound “tubey” or “solid-state like”, or even a perfect hybrid of
the 2, it just sounds very much like live music. There was an
enormous amount of inner detailing, but the sound was not
etched, hyperdetailed, or “analytical” sounding. Rather, the
inner detailing was perfectly integrated and joined, not
separated, from the musical experience. It has been written
that one of the wonderful features of the Audio Research Ref 3
Linestage is that it had a “lit from within” quality to each
sound and performer. I am glad to announce that the Purity One
also has this wonderful quality in spades! The soundstage had
outstanding depth and width with billows of air surrounding each
performer and only limited by the recording (as it should be).
The requisite pace, rhythm, and timing (PRAT) was most certainly
there sounding both natural and realistic with the Purity One
lending music excellent propulsive drive and excitement. Very
importantly, the Purity One was supremely quiet allowing me to
listen far into the soundstage and capture all the subtle inner
details, especially appreciated on the more quiet passages of
different performances!
There are 4 areas where I find many
preamplifiers, even very well-regarded ones, to present the
biggest challenge: 1) First is reproducing the fast leading
edge, then the body, and then the long and natural decay of each
instrument and voice. 2) Second is keeping the soundstages full
depth and width to the limit of the recording locked in place
and well separated during very complex/dense passages, instead
of being reduced to an incomprehensible morass of sound. 3)
Third is reproducing both macrodynamics, and, more importantly,
microdynamics in a realistic way. I consider the microdynamics
to be the life of the music—its moment to moment
breathing/living aspect of live music and sound that when
absent, makes music dull, boring, and lifeless. 4) Fourth is
being able to produce natural intensity/amplitude uniquely to
each individual performer in correct time both individually and
then collectively against every other performer at each passage
of each performance.
Fortunately, amazingly, and rather uniquely
in my experience, the Purity One passes all of the above
challenges with ease. I will follow some specific listening
examples:
1) Credo/Grimaud, Salonen, Swedish Radio
on Deutsche Grammaphon: This is a true stereo and
preamplifier musical torture test! The piece selected “Credo”
by Arvo Part performed by the Swedish Radio Symphony Orchestra
conducted by Esa-Pekka Salonen and with performance by Helene
Grimaud. This selection (track 7) tests all (4) of the above
preamplifier challenges (especially #2) and more. This
selection ranges from ppp to ffff and all ranges in
between! This SACD was loaned to me by a fellow Physician and
music lover whose relative had a long career in opera in Vienna,
Austria. Only the most top tier preamplifiers/linestages will
avoid a crash and burn on this test in that the extreme
intensity and density of the score collapse into an utter
confusion and cacophony of sound instead of keeping all the
separate performers perfectly positioned in space within the
soundstage as well as properly rendering the individual and
collective amplitudes and timing. My friend who loaned me this
SACD was shocked at how well the Purity One did on this intense
and difficult to reproduce score—Bravo!!
2) Usher Audio “Be there” Demonstration
Disc: This is a wonderful disc with every recording
sounding detailed, balanced, and natural sounding. Many of the
selections contain different languages from Taiwanese to French
to Spanish to Latin. I especially enjoy the “Royal March from
the Soldier’s Tale” on track #11 which contains bass drum and
snare drums, clarinets, and all manner of brass from tuba, to
trombone, to trumpets. I listen for the naturalness of each
instrument’s timber, which sounded extremely natural and
realistic (perfect “blat” of the trombone) with phenomenal
microdynamics with the Purity One. What I noticed the Purity
One also really got right probably more than any other preamp I
have tried was the initial attack of the bass drum, followed by
a powerful pressure wave that I both felt and physically
experienced a it slammed against my chest followed by a very
natural decay of each struck stroke—absolutely amazing!
3) Mormon Tabernacle Choir “Choose
Something Like a Star”. I love every selection, but
especially listen to Track 9 “Say Ye to the Righteous” and Track
12 “Ye Shall Have a Song”. The Purity One gets the space, hall
sound, attack, sustain, and decay of the mass chorus right with
superb separation of individual voices in each section as well
as outlining each section (there are 8 sections) as good as I
have heard.
4) Paul Simon’s “Graceland” (Newest
Version). Check out track #13 “Diamonds on the Soles of Her
Shoes” which has one of the best electrical bass guitar runs of
any recording I have ever heard. The Purity One gets the speed,
fullness, vividness, and drive perfectly and draws me into the
music with a stunning rendition.
Conclusion: The Purity One
Linestage is absolutely a top, top tier musical masterpiece! It
sounds as much like a live performance as any
preamplifier/linestage I have heard/auditioned to date. It
presents with fast, clean, deep, powerful, and natural bass; a
vivid 3-dimensional midrange with full-bodied performances, and
huge airy and extended high frequencies with proper soundstage
width, depth, and height from the very front the furthest
reaches back with soundstage only limited by the recording. It
gets the leading edge, body, and then decay of each note right
and doesn’t collapse the soundstage on extremely complex
passages (as do many other preamplifiers/linestages). It allows
one to hear the musical intensity (amplitude) of each performer
individually and collectively that one hears at live
performance. It also breathes life into the music with its
excellent microdynamics. Its quietness allows low level details
to be easily heard and allows one to listen deep into the
soundstage. My only reservation about my review unit was the
lack of remote control which appears to be remedied in the new
Purity One Model. Unhesitatingly recommended!!
name withheld
Manufacturer Comments:
Thank you for such an in depth, detailed
review of our Purity One tube linestage. The Purity One is the
result of many years of research and testing of several design
concepts. We are honored to hear that your experience with the
Purity One directly reflects or design goals with this unit.
As you so kindly mentioned, the production
Purity One linestages will in fact be equipped with a full
function remote control offering the user the ability to control
volume, mute and source selection from the comfort of their
listening position. New units will also come housed in a new
chassis design sharing some of the lines and family resemblance
of the Purity Reference Balanced linestage.
