Product Review - Wright WLA-12A
Tube Preamplifier & Parasound P/LD-1100 Solid State Preamplifier - May, 2000
Jason Serinus
Wright
Sound Company |
Parasound Products, Inc., 950 Battery Street, San Francisco, California 94111; Phone 415-397-7100; 800-822-8802; Fax 415-397-0144; Web http://www.parasound.com |
A TALE OF TWO
PREAMPS
OR
HOW I OVERCAME IMPEDIMENTS
AND GAINED A GREATER APPRECIATION
FOR WHAT'S
LESS AND WHAT'S MORE
The Wright Sound Company WLA12A Line
Drive Tube Preamplifier
Specifications:
Tubes:
2 x 6SN7, 1 x 6EM7, 1 x 6X5
Polarity:
Inverting
Frequency
Response: Better than 20 Hz to 20 kHz , plus/ minus 1 dB
Very
Linear 6 SN7 voltage and driver stages
Distortion:
Less than 0.4 percent total harmonic distortion
Input
Impedance: 100 kOhms, nominal
Output
Impedance: 2 kOhms, nominal; will drive loads down to 600 ohms with some loss
of output level
Voltage
Gain: 12 to 20dB, switchable on back
Noble
Audio Mastering pots
Hovland
Musicaps© in line stage
Worldwide
voltage switch
Tube
rectifier and regulation for truly quiet operation
Output
Level: 1 volt PP nominal; will drive up to 20 volts PP
Stereo-mono-stereo
reverse switch
Output level control: 0 dB to - 10 dB, plus Full Mute
Tape
record and playback compatible
Weight: 7 lb.
Size:
6 x 10 x 5 inches
Warranty:
Limited one year parts and labor, tube warranty 90 days.
MSRP: $695 USA
The Parasound P/LD-1100 Line Drive Solid State Preamplifier
Features:
Dual mono circuit designed by John Curl
Six line level inputs
Direct coupled -- no capacitors in signal path
Complementary hand matched MOSFET drive circuit
100% pure Class A circuitry, 44,000 µF power supply filter capacitance
Separate glass epoxy circuit boards for each channel
High current dual mono headphone circuit
Tiffany-style gold plated RCA jacks
Motorized volume control with LED indicator
Fully remote controlled, including input selection u External infrared
remote input
Removable IEC AC cord
12 volt DC automatic turn-on trigger output
2 rack space mounting adapter available
Specifications:
Frequency
Response: 5 Hz - 135 kHz, +0/-2 dB, full output; 5 Hz - 100 kHz, +0/-2 dB,
full output -6 dB
Frequency
Response: 5 Hz - 135 kHz, +0/-2 dB, full output; 5 Hz - 100 kHz, +0/-2 dB,
full output -6 dB
Total
Harmonic Distortion: 3⁄4 0.005%, 1 kHz; 3⁄4 0.007%, 20 kHz
IM
Distortion: 3⁄4 0.004%
IM:
unmeasurable
Maximum
Output: > 10 V before clipping
Input
impedance: 30 kOhms, ± 5%
Output
impedance: 60 ohms
Recommended
line load: 600 ohms
Recommended
headphone: 8 ohms
Input
Sensitivity: All inputs 150 mV, ±5%
Maximum
Input Level: 10.5 V before clipping
S/N
Ratio: > 102 dB, A-weighted, full output; 93 dB, A-weighted, full output -6
dB; > 84 dB, unweighted, full output; > 81 dB, unweighted, full output
-6 dB
Maximum
Hum: > 0.05 mV, full output; > 0.08 mV, full output -6 dB
Crosstalk:
> 100 dB, < 10 kHz, full output; > 96 dB, 20 kHz, full output; >
90 dB, 20 kHz, full output -6 dB
Channel
Balance: 3⁄4 0.3 dB; 3⁄4 1 dB, -60 dB
Dimensions:
w 171/4" x h 3" x d 16", h 35/8" with feet
Weight: 16 lb.
Size:
6 x 10 x 5 inches
MSRP:
$850
Warranty:
Ten years parts, five years labor; two years p/l for moving parts. Original
owner only when purchased from an authorized Parasound dealer.
REVIEW SYSTEM:
Michael
Green Chameleon III tunable speakers (modified with Nirvana hook-
up
wire and Scan Speak 2905/9700 tweeters);
Hsu
HRSW12V powered subwoofers (stereo pair);
PASS
Aleph 5 60W pure Class A poweramp/Bruce Moore Dual Seventy
Wideband
Tube Poweramp;
Bruce
Moore Companion III tube preamp;
Theta
Gen. 5A single-ended DAC;
Genesis
Digital Lens with BNC in and out;
Audio
Alchemy DDS-Pro transport;
PS
Audio P300 Power Plant;
AQ
Dragon II speaker cable to the Chameleons;
AQ
Clear II speaker cable to the Hsus;
Nirvana
interconnect from amp to preamp;
AQ
Diamond II co-ax interconnect from Hsu amps to preamp;
Tara
Decade interconnect from preamp to Theta DAC;
Nirvana
digital (BNC) interconnects from Theta to Lens and Lens to transport;
Power
cords by MIT, Synergistic, Harmonic Technology and XLO;
Michael Green Deluxe Ultrarack and
Basic Racks; MG audiopoints and room treatment; Black Diamond Racing Cones;
inner tubes, maple cutting boards and bags of sand, homemade bass traps;
Shakti stone and many Shakti On-Lines; Bedini Ultraclarifier, Audioprism
Stoplight and Blacklight
Introduction
Some months back, my helluva guy
fellow reviewer, Paul Knutson, asked me if I wished to review the Wright WLA12A
Tube Preamplifier. Since the diminutive, lightweight $695 Wright sells for a
significantly lower price than my far larger, heavier $3000 Bruce Moore
Companion III Tube Preamp, I realized that, unless the Wright was the biggest
steal on the market, I would have to adjust my expectations in order to give
the it a fair evaluation. Obtaining a second preamp in the Wright's price
range, and performing a comparison between the two, seemed the most
responsible way to proceed.
At
the same time as Paul and I were working out review logistics, I was setting
up a Bay Area Audiophile Society demonstration of the new Perpetual
Technologies P-1A/P-3A combo. (Expect Paul's review in the fall). Given that
Perpetual Technologies' founder, the estimable Mark Schifter, was flying
into San Francisco from Colorado especially for the demo, he decided to
lighten his load by asking Parasound Products of San Francisco to supply the
demo amp, preamp, and transport. Parasound brought along its P/LD-1100
Line Drive Solid State Preamplifier, an $850, John Curl-design that, despite
being on the market for a number of years, has been passed up by reviewers in
favor of its now-discontinued big sister/brother. The opportunity to compare tube
and solid state products of roughly the same price point (especially if you
consider the $80 cost of the replacement 6SN 7GT tubes I eventually used for
the Wright review) was too enticing to pass up. Upon broaching the subject,
Parasound graciously supplied me with a brand new review sample.
The Drama Unfolds
No
one who has received multiple shipments of high-end gear will be surprised to
learn that UPS did not treat the Wright shipment as though it were a gift from
the Gods. When Paul removed the preamp from its damaged carton, he discovered
that the supplied 6SN 7GT tubes had received the kind of jolt that made him
uncomfortable turning the unit on while he was in the same room. After
replacing the traumatized stock tubes with Sylvania JANCHS 6SN 7GT short
bottle tubes (approx. $20 apiece), he brought me the unit.
The
Wright comes with a non-removable, two prong, non-polarized, lamp cord-style
power cord. With the help of a polarity tester, we determined the best way to
plug the unit into my P300 Power Plant. We also discovered another use for the
“green pen” CD Stoplight (which I use on all my CDs): it's a great tool
for marking polarity on plugs.
Paul
told me nothing about the little switch on the back of the preamp. In fact, he
forgot the instruction booklet entirely. Acting on blind faith, we connected
the Wright to my Pass Aleph 5, made sure nothing would blow up when we turned
everything on, and bid each other a fond farewell.
Not
for long, though. To put it simply, the Wright preamp sounded lousy. No
midrange to speak of, and hardly a semblance of bass. Even on a simple
voice/piano recital, the lower notes of the piano seemed less substantial than
claims that any particular bag lady is really an incarnation of the Virgin Mary. Calls
to Paul, and then to Mom and Pop Wright, revealed that, even if I had been
given the instruction booklet and/or gone to the Wright website, I would not
have been informed that this preamp inverts polarity. Not right, folks. So,
the first step was to switch around my speaker cable leads.
(You
might ask, why not simply flip the polarity switch on your Theta DAC? Some
designers counsel against this practice, stating that it adds an extra circuit
to the signal path).
Alas,
the much-anticipated dramatic improvement failed to occur. When Paul made his
second pilgrimage across the San Francisco Bay to Serinusland, he brought
along, not only the much-lamented manual, but two Sylvania tall bottles ($40
apiece). These did improve the sound somewhat, but not enough to convince me
that I could say good things about what I was hearing.
Then
Paul said, “listen to this.” First turning the preamp's quite-vocal Mode
selector switch to mute, he bravely disappeared behind my rack, venturing into
the black hole from which several former high-end reps have yet to reappear.
With the faith of a true hero, he lingered long enough to flip a previously
unidentified, equally vocal switch. Voila, or rather CLICK, a veil lifted,
enough to convince me to ask the pallbearers to remove the casket they had
just delivered for the nearly departed Wright.
Exclamations
of “Whatdja do?” revealed that Paul had initially lowered the voltage gain
by 8 dB by flipping the Gain switch at the back of the preamp to the low
setting. Doing so inserts a resistor in the signal path. With low gain, the
initial volume of the preamp is lowered, and one has more flexibility in
volume adjustment with the unit's detented volume control. However, prior
experience with such an option on both the Bruce Moore Companion III CD1 input
and the Audible Illusion's Modulus 3A CD input has convinced me that putting
extra resistors in the signal path tends to dampen highs, decrease dynamics,
and in general suck life out of sound. Unless one needs significantly extra
gain at the upper end of the volume control, which may be called for by some
analog set-ups, a far better solution is to either live with the higher gain
or ask the manufacturer to readjust the dB increments on the detented volume
controls. This is what several of my Audible Illusions-owning friends have
done, and what I have done with my Bruce Moore preamp.
With
the switch flipped high gain, "Dusty" Knutson emerged
victorious. Yes, the difference was major. Convinced that the world was now a
better place, he swept away the dust the pallbearers had left, and made his
way back to the safe confines of San Francisco
. . . but,
a bit too soon.
Impeded by Impedance
I
then assembled my trusty pile of test CDs, a pile that grows as I continually
encounter and review new recordings. I demagnetized, listened, noted,
switched, breathed, fussed, pondered, bemoaned, belabored. I called Paul,
consulted psychics, prayed to Buddha, cursed the universe. Nothing would make
the Wright sound right.
I
then tried the Parasound. As with all equipment, I thoroughly broke in the
unit, played demagnetizing and break-in tones, and gave my cables adequate
time to settle in. The difference between the two preamps was so great that
the results seemed unfit to print.
Upon
phoning our illustrious founder/owner/editor/proprietor, John Johnson, to
tell him I was throwing in the towel on the Wright, he asked about the input
impedance of my Pass Aleph 5. “10 kOhms in single-ended mode, 25K in balanced
mode, I reported upon checking the manual. And since these two preamps are
both single-ended, 10 kOhms is what it is and will be. “That's much too
low for a tube preamp with such a diminutive power supply as the
Wright's,” he replied. “No wonder it doesn't sound good. You've got
to use a power amp with a high input impedance before you can get any sense of what
the unit sounds like.”
Happily,
I had on hand a review sample of the Bruce Moore Dual Seventy Tube Power
Amplifier. The
input impedance of this unit is 100KOhms, ten times greater than the
Pass's. While replacing the Pass with the Moore didn't make the Parasound
solid-state preamp sound very different, it totally resurrected the Wright.
Besides an annoying, ever-present hum, which careful tube matching can
hopefully eliminate, this little preamp finally came into its own.
HIGH-END LESSON NUMBER 5,332.
Careful system matching is essential with tube preamps.
Good-bye
to hours of listening and a page of notes. (When I figure out all the time I
have spent reviewing these two preamps, I'm probably going to make $1/hour).
Time to start anew.
Feature Comparisons
While
both preamps offer two main outputs, a separate tape output, a tape input, plus
four other inputs, the Parasound also offers a “Direct” input jack. Since
this jack feeds a separately switched line level input boasting the most
direct signal path to the power amplifier, I used it exclusively when testing the
Parasound.
The
Parasound also has remote control, which I didn't use. There was no sonic
reason for not using it; I simply am accustomed to jumping up and down like an
idiot every time the volume needs adjusting. Volume adjusting is in fact
easier on the Parasound, because the volume control is not detented. The issue
I have encountered on other preamps of wanting to set the volume to the
unavailable level between two clicks did not have cause to surface here. For ease
of operation alone, the Parasound preamp is a winner.
I had plenty of time to perform my comparisons, because the Bruce Moore Companion III Preamp I've grown to love was stuck in the shop having the gain on its detented volume controls adjusted. I played the selections I was reviewing first on the Parasound, then on the Wright. Since the Parasound offers a detachable power cord – yet another plus – I auditioned it both with a Synergistic Master Coupler and the “stock” power cord that comes with the unit (allowing time for break-in, of course). Parasound assured me that this cord, which is hand-soldered, is a step above most “stock” cords. To put it simply, they are correct. Once broken-in, it is still a step above the basic, non-polarized power cord that the Wright family supplies. Ah yes, it's polarized. Yet another point for the Parasound.
Doing Right by the Wright, while Pairing with the Parasound
I
used the same selections when reviewing both the Wright and Parasound preamps.
Comparison included an extended listening period with the new DG recording of
Dvorak's Symphony No. 9 (“From the New World”) conducted by Claudio
Abbado, which I was reviewing at the time.
First
up were various tracks from J.S. Bach's well-loved Brandenburg Concertos,
played on authentic instruments by the Berlin Academy for Ancient Music. This
is no staid academic performance. Originally reviewed with the fabulous $6,550
Bruce Moore Dual Mono Preamp in the signal path, these two discs offer a
veritable riot of color and sound, qualifying as among the best, consistently
engaging recordings of the Brandenburgs on the market.
Though
the Parasound lacked an ultimate sense of instrumental color, color was
nonetheless present. Everything sounded a bit toned down and muted compared to
what I'm used to hearing, however. Images were distinct and well defined –
a definite plus. But I missed the push and splatter of the authentic
instrument horns on the first Concerto's first movement. (Once you hear this
on a great system, you'll know what I'm talking about; many older
instruments sound less smooth than those employed in modern orchestras. This
can give them the extra bite that makes for a lauditory auditory experience.)
I also noted a lack of vibrancy and brilliance to the highs, and a lack of air
around images. By comparison, I found the highs on the Wright, though also
lacking ultimate brilliancy and sheen – I am not talking about sharpness or
artificial, hard-edged stridency here – seemed more convincing. I especially
liked the sound of harpsichord, even though it, like everything else, had less
body and substance than I would have liked. In fact, I found the Wright more
transparent and exciting on this music. The Wright's transparency added a
sense of depth that I had not previously heard with the Parasound. I also
experienced what seemed like a wider, more involving soundstage, and a
semblance of air around instruments. As I proceeded to do my comparisons,
however, I consistently wondered if this was due in part to the fact that the
Parasound seems to “fill in the spaces” more with midrange substance,
while the Wright can sound a bit lean.
Next
came the 24-bit Sony disc of mezzo Susan Graham's superb La Belle Epoque
recital of songs by Reynaldo Hahn, with Roger Vignoles at the piano. Having
just had the privilege of sitting in the first row for Susan Graham's
Berkeley recital, as well as hearing her warmups from farther back in the
empty house, I can state with confidence that I know how marvelous she sounds
in real life.
The
body of Graham's voice and the low notes of the piano came through
wonderfully on the Parasound. But again, everything was a bit muted, with the
ultimate life of the music diminished. There is a passage at the end of
Hahn's A Chloris where Graham executes an exquisite, perfectly controlled
dimuendo on the world “ambrosia,” her voice sinking deeper into her heart.
While I could hear this effect on the Wright, it made much less impact than on
my $3,000 reference Moore (or on the $1,650 Bruce Moore Companion II-b I
originally owned – see review Secrets published recently). And while the highs
were more vibrant on the Wright than on the Parasound, I again experienced a
lack of brilliancy which felt like a mild scrim had been thrown across the
stage. Within the Wright's diminished tonal window, however, timbre seemed
true.
I
first heard the superb final “Blues No More” Track of the JVC-XRCD release
of Terry Evans' Puttin' It Down at the San Francisco Hi-Fi Show a few
years ago, and
immediately fell in love with his singing, the arrangement, and Ry Cooder's
guitar. This is a great recording, with lots of space, fine percussion, and
much musical room to breathe. It's one I use consistently when reviewing
equipment.
With
the Parasound, cymbals lacked spark, and the beginning strums of the electric
guitar lacked visceral impact. Ultimate slam was also missing from the drums,
and bass lacked the clarity I was used to hearing. The recording still came
across as superb, but it was not as involving as when heard through more
costly preamps. I especially wanted more control on the bass. But this is
something I wanted from both the Wright and Parasound preamps. With both
units, in the range where my room has problems controlling bass, those
problems became more pronounced.
My
experience with the Parasound remained unchanged while auditioning both the
DG, reverse polarity Boulez recording of Mahler's Symphony No. 6 and the
head-over-heels superior sounding Reference Recordings disc of Argento's
Valentino Dances (what a stunner). Though drums were round and full,
everything again seemed a bit damped.
While
each preamp seemed plagued by noise floor issues, which created a scrim on the
sound and a lack of brilliancy on the highs, the greater transparency and air
offered by the Wright led to a more involving presentation. Even though it
hummed excessively (though not annoyingly), and did not “fill in” the
midrange as well as the Parasound, I found myself listening to it longer
before switching between selections. My God, I was actually enjoying myself!
When it came time for me to meet a CD review deadline by comparing recordings
of the Dvorak Symphony No. 9, I chose the Wright for my work.
I
spent many hours using the Wright preamp to compare the Abbado DG and
Harnoncourt Teldec recordings of Dvorak's Ninth Symphony, especially when I
threw a historic 1929 Erich Kleiber recording in for further comparison. I
could never get the volume setting exactly right, wishing to place it mid-way
between two of the detents. (Nothing new; as discussed above, this situation
is common with detented volume controls. It seems manufacturers set them this
way because analog setups with phono preamps often need significantly higher
gain than other components. For those owners for whom this is not an issue,
having the volume control detents readjusted by the manufacturer is
definitely the way to go.)
The
Wright would get a little noisy in the loudest passages, moreso than the
Parasound (I never felt the Parasound straining). I also missed the rich
color and impact fullness of the double basses; enough of it is there to
satisfy, but the Wright is ultimately better on highs than on lows. The
exciting thwacks on the drums were also undeniably audible (far better
captured by Teldec than DG). Most importantly, the musicality of the symphony
came through. All in all, though lacking the fullness, clarity, visceral
impact, and vibrancy of the sound of higher-priced equipment that is worth the
money one pays for, the Wright was still musical and involving. And this,
ultimately, is what matters.
Final Thoughts
There
is an adage in the audiophile industry that, above a certain price point, one
receives diminishing returns for the amount one shells out. My experience with
these two preamps has convinced me that, for under $1000, one can definitely
obtain a musically rewarding preamp that can bring much pleasure. If, however,
one is willing and able to pay the extra bucks, and already possesses the
quality of equipment and cables that warrant spending more on a preamp, the
rewards are great in the multi-kilobuck categories.
A
case in point. Over a week after completing my preamp comparisons, my Bruce
Moore Companion III made its way home. Even before the new resistors which
control volume gain had broken in, the differences between it and these units
was apparent. I can best describe these differences by offering an analogy.
Have you ever experienced the live sound of a full symphony orchestra, heard
from a good seat, after previously only having heard symphonic music
reproduced on a mass market, run-of-the-mill home system? That's the
difference in impact between a worth-the-money $3,000 unit and these two
particular preamps that cost under $1,000.
Be that as it may, these lower cost preamps offer many rewards. The remote controlled, detachable power cord, non-detented volume control, solid state Parasound offers far more flexibility and ease of operation than the Wright, and may prove the superior choice when matched with the overly bright components one too frequently encounters in this price range. It also has a much better warranty, and lacks all those noise, burnout, heat, and matching problems one can encounter with tubes. (Solid state is far better suited for tight quarters, I might add, because it won't heat the room nearly as much.) The Wright, however, when CAREFULLY matched with the right components, offered at least one listener a more rewarding and inviting musical experience. Just remember to choose a power amp with a high input impedance, i.e., 50 kOhms or above.
The reader whose first priority is music would prove wise to audition both these preamps, as well as others in their price range and above, for example, the much-touted $1,250 Adcom GFP-750 preamp. Take these units home, give them time to settle in, and hear for yourself which one has you coming back for more.
- Jason Serinus -
© Copyright 2000 Secrets of Home
Theater & High Fidelity
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