| The
Multiple
Personalities
Of
Perpetual
Technologies'
P-1A /
P-3A
Digital
Processors |
|
|
|
Marshall
Nack |
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2
March 2001 |
Preface
This
is my first foray
into high-end
digital. Even
though I'm a
happily dedicated
vinylphile, I know
I've been missing
the last 20 years'
worth of
recordings. The
thought
occasionally
crossed my mind
that something
good might have
happened in
classical music
after the left
turn the genre
took in the second
half of the
twentieth century.
Especially in my
(current)
principal area of
interest, the
Baroque, I know
that there are
some fantastic new
players on the
scene. I wanted to
get my feet wet
with a respected
but affordable rig
and gradually move
up later on. The
PT gear fits the
bill.
Cosmetics
The
two units are
small enough to
fit side by side
on a component
shelf. They're
each about the
size of a quality
paperback and
weigh four pounds
apiece. They look
like high-tech PC
computer
accessories. Fit
and finish is
adequate but not
in the same league
as, for example,
Krell gear.
Likewise, the AC
wires are
decidedly mid-fi.
I set the two
pieces up in the
vertical position
with their
supplied aluminum
brackets on my
PolyCrystal rack.
Since
one purpose of
this review is to
gauge the impact
of the Monolithic
Power Supply
upgrade, I used
the PT gear
without any AC
conditioning until
the Monolithic
arrived. I
connected the
digital front end
to the Ensemble
Mega PowerPoint AC
power strip and
that went straight
into the wall.
I
acquired a SONY
DVP S7000 for the
purposes of this
review. The SONY
made a stir a
couple of years
ago as a CD
transport and
commands respect
in that regard.
Getting
Started — A
Small Problem
After
about a week of
burn-in, I sat
down and ran
through the
setting options
and, believe me,
there are many!
When I switched
the P-1A to CD
Resolution
Enhancement I
detected a
constant high
frequency whistle,
even with the
volume at zero.
The noise was just
loud enough to be
audible from the
sweet spot.
Because of this, I
switched the P-1A
to Bypass,
circumventing
Resolution
Enhancement for
the time being,
until some help
could arrive from
PT.
Clement
Perry came by one
day and suggested
that substituting
an Acoustic Zen
MC2 Silver coax
digital cable for
the I2S cable
would improve the
sound. The I2S
cable, which comes
with the units, is
PT's preferred
digital link. I
followed Perry's
suggestion and,
sure enough, the
Zen did sound
better, with
improvements
immediately
noticeable in
treble extension,
spatial
definition, and
soundstage
openness. I left
both cables
connected so I
could easily
compare them. But
with Resolution
Enhancement that
noise was still
there.
The
problem's solution
came purely by
accident. One day,
thinking I might
tidy up the
unsightly wire
mess, I removed
the I2S cable.
That was it! With
the I2S out, the
whistle was gone!
I contacted Mark
Schifter, who
diagnosed the
problem over the
telephone as a
ground loop. The
grounding
configuration of
the I2S cable is
different from
that of the coax.
When the I2S is
used, roughly 50%
of systems need to
be grounded; the
rest need the
ground lifted. At
his suggestion, I
put a 2-prong
cheater AC adapter
onto the power
cord for the P-1A.
Then I connected
the I2S cable,
switched to
Resolution
Enhancement, and
no noise! Now I
could explore the
gear's
capabilities.
I
was still worried
that, even without
the I2S cable, I
might have a
system problem
causing the ground
loop. Nothing to
worry about,
according to Mark.
Simply lift the
ground when using
the I2S; otherwise
leave the system
AC alone. The
ground loop with
the I2S does not
mean there's a
systemic problem.
Initial
Impressions
I
wired up the PT
gear with all
Acoustic Zen
cabling, including
two lengths of the
MC2 Silver coax
digital, the
Silver Reference
analog and the
Krakatoa power
cord. With the
P-1A in its Bypass
mode, the sound
was smooth, with
no glare
whatsoever — so
smooth that it
sounded as if I
was using a
top-notch AC
conditioner. In
Resolution
Enhancement mode
it was even
smoother, too much
in fact. There was
no question that
Resolution
Enhancement was
smoothing edges
and blunting
transients, with a
concomitant loss
of information. It
was also rolling
off the treble.
The sound was
homogenized. The
Bypass mode had
more edge, more
powerful
transients, less
smoothing effect.
Note: I tried the
PT gear in another
system without any
AC conditioning
and found the same
results.
Then
I tried using the
P-3A by itself as
a DAC. This
sounded good —
not as smooth and
relaxed as with
the P-1A in place,
but on the other
hand, without
objectionable
digital artifacts.
In fact, the PT
gear never sounded
objectionably
digital in any of
the setup
variations I
tried.
The
Two Faces of Pt
— Meet The Other
Face
Still
waiting for the
Monolithic P3 to
arrive, I decided
to see what would
happen using my
full AC
conditioning
package on the PT.
I employed an
extravagant
combination of the
Accuphase PS-500
sine wave shaper
in series with the
Legend Audio Live
Performance. All
components are
then connected to
the Legend. WOW! I
was stunned — a
night-and-day
difference! Then I
installed a Kimber
Kable Illuminati
Orchid digital
interconnect.
KABOOM! The
Illuminati and the
AC conditioning
made all the
difference in the
world.
The
improvement was
vast. The
objectionable
smoothness was
gone. The
Resolution
Enhancement mode
presented a wealth
of detail. The
sound grew bigger,
more vivid, more
impressive. Tonal
balance, timbre,
and overtone
information were
spot-on. The
bottom had more
fullness and
extension. The
mids were fleshed
out and the treble
quite extended,
without glare or
harshness. There
was no grain to
speak of. Violins
sounded more like
themselves. (I
find this
impossible to
describe; they
simply sounded
more real.) The
PT's presentation
had now
transformed. It
was a close second
to my analog
source.
In
a face-off of Waltz
for Debby by
the Bill Evans
Trio between an
Original Jazz
Classics CD
(OJCCD-210-2) and
a Riverside LP
reissue (RLP
9399), the winner
was too close to
call. The CD's
bass response went
lower and was
tighter, with
better
articulation and
definition. Then
there's that
wonderful ability
to handle
crescendos without
breakup, cleanly
and distortion
free, with
effortless dynamic
expansion beyond
that of my analog
rig. On a larger
percentage of
recordings the
soundstage
exhibited terrific
width, depth, and
image separation.
The presentation
was larger and
more vivid. I was
reminded of the
intense saturation
of Technicolor
movies. Yet
compared with
analog, the CD's
bass lacked the
treble overtone
component, and
therefore sounded
dull and
artificial. Most
recordings seemed
too closely miked
— too up-front
for my taste,
perhaps the result
of cable effects.
At the same time
the overall sound
erred slightly on
the soft and
relaxed side, with
transients
remaining a little
dull.
Nevertheless, the
experience went
way beyond my
expectations.
Analog was getting
a run for its
money. We were in
a place where a
change of power
cord could make or
break a
comparison.
Scaling
the Heights
When
I did A–B
comparisons of the
Duke Ellington Blues
In Orbit on
Mobile Fidelity CD
(UDCD757) to the
Classic Records 45
RPM re-issue LP
(CS8241-45) of the
same recording,
the differences
between the two
mediums were more
apparent, and
swung further in
favor of the
analog. Had I
listened only to
the CD, it would
have been
completely
satisfying, but by
comparison with
the 45 RPM LP, the
CD was reduced to
a two-dimensional
facsimile. One
must keep in mind
that normal
listening involves
average quality
LPs and CDs, and
that the 45 RPM
recording is well
above average. I'm
not the kind of
audiophile who
plays the same 30
perfect LPs over
and over.
Additional
Recordings Used
for This Review
Classical
The defunct FI
magazine Deutsche
Grammophon sampler
The Originals,
(DG 457 098-2):
Corelli
– Concerti
Grossi Op. 6
numbers 7 – 12,
Philharmonia
Baroque Orchestra,
led by Nicholas
McGegan, Harmonia
Mundi (HMU
907015), Peter
McGrath engineer.
This performance
rates five stars,
while the sound
gets about four
stars. I did
notice a constancy
or
"sameness"
to the decay that
sounded
artificial.
Indeed, this is a
studio recording
and any reverb
that's present, I
bet, is a
post-production
addition. The
Acoustic Zen
cables accentuated
this decay, while
the Legend
lessened it.
Jazz
The FI
magazine Analogue
Productions
sampler,
especially track
14, the Bill Evans
Trio doing
"My Foolish
Heart".
Portraits
in Ivory and Brass
CD, Mapleshade
(02032)
Tweaks
and Fine Tuning
I
used a Shakti
Stone over the
SONY transport,
with PolyCrystal
Ref ISO 3 Footers
under it. The
Audience Power
Chord on the P-1A
(prior to getting
the Monolithic P3)
sounded good. It
added body and
fullness. Later, I
tried a new Legend
power cord and
enjoyed its
analog-like
warmth. The Legend
cord has a quality
that I would
describe as
"coherency."
The frequency
spectrum is
presented in equal
proportion and
arrives
time-aligned at
the listening
position.
Kimber
Kable's Illuminati
Orchid digital
interconnect
sounded superb. A
Harmonic Tech
Silver balanced
cable saw play
time, and the
Legend Digital
Reference
interconnect
replaced a length
of Acoustic Zen
MC2. The Legend
cable has less
treble bloom than
either the Kimber
or HT, but was
more coherent and
analog-like, just
like the Legend
power cord. Top
picks for the
digital cable
would be a toss-up
between the
Illuminati and the
Legend cables.
Perpetual
Technologies'
Setup
Recommendations
Jon
Lane of PT
recommends these
two scenarios,
depending on the
digital cable used
to connect the
P-1A to the P-3A:
-
For
I2S
connection:
set the P-1A
to 24/96. Use
the I2S cable
and engage I2S
Direct mode in
the P-3A. This
will eliminate
redundant
upsampling in
the P-3A input
receiver.
-
For
other cable
types: defeat
the upsampling
in the P-1A
and let it
happen in the
P-3A. Use
these switch
settings on
the P-1A:
Select
Resolution
Enhancement,
44.1 sample
rate, and
24-bit output.
The P-3A will
see a 24-bit,
44.1 sample
rate, and will
upsample to
96k. Since
this is just
prior to D/A
conversion, it
will
theoretically
have less
jitter, and
should sound
better.
Scenario # 2
worked best
for my cable
arrangement,
and I used it
for the bulk
of my
listening.
Additional
Tech Points
Resolution
Enhancement
constructs the
24-bit words. The
P-1A does this by
interpolation,
converting 16 bit
words to 24-bit
words using
preprogrammed
algorithms.
Bypassing
Resolution
Enhancement, the
P-3A will use
16-bit words to
convert to analog.
Each
input cable type
has to have the
sample rate
selected
individually. If
you programmed 96
when using a coax
cable, you will
have to re-program
if you switch to
AES/EBU. Go
through the
settings once for
each cable type.
The unit as
shipped is set for
I2S usage.
Don't
connect more than
one input to the
P-3A at a time.
Avoid connecting
both the I2S and a
different cable
type in order to
do A-B testing,
because this has
the potential to
cause ground
loops.
Conclusion
The
P-1A/P-3A combo
has multiple
personalities.
When used without
the Monolithic P3
or the benefit of
decent AC power
line conditioning,
I think you can do
better elsewhere.
However, when
external power
conditioning is
employed, another,
the units reveal
another, more
exciting
personality. It is
only in tandem
with excellent AC
conditioning that
the PT combo can
scale the sonic
heights. I was
shocked at how
close the sound
was to my analog
rig, which retails
for about five
times the price. I
had always assumed
that analog would
remain
unassailable. You
can gauge how good
the fully
accessorized PT
combo is if I tell
you that I've
actually started
to buy CDs now. I
have not
auditioned the
competition, but I
would think you'd
be hard pressed to
find a better
value in this
product class.
POSTSCRIPT:
Arrival of the
Monolithic P3
The
stock power
supplies are made
to a price point.
Hence, the
optional
Monolithic Power
Supply represents
an obvious
upgrade. It has a
female IEC
connector to
accept an external
AC power cord, and
12 VAC and 9 VAC
output jacks for
connection to the
P-1A and P-3A,
respectively.
However, the
supplied
voltage-carrying
wires appear to be
the same mid-fi
quality as the
ones supplied with
the stock
wall-wart power
supplies. The good
news is that the
Monolithic P3
Power Supply is
indeed an
improvement.
Connected into the
Ensemble AC
distributor, it
presented a
layered
soundstage, pure
and clean. I could
have stopped at
this point and
been happy. Using
the P3, it was
only by comparison
that some degree
of smoothing was
apparent without
AC conditioning,
yet further
refinements
appeared all areas
when I added the
Legend Live
Performance. In my
view, using the
Monolithic P3 in
conjunction with
my other AC
conditioners puts
the PT into a
rarified realm.

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