Monolithic Sound PA-1 Preamplifier and
HC-1b Dual Mono Power Supply
It has come to my attention that some of you
ladies are having a hard time figuring us guys out. As much as I'd like to believe we're
terribly complex, the truth is, we're not -- a fact that has made Maxim's publisher
Felix Dennis a very wealthy man.
Being women and all, you've probably already noticed a few
of the things that make us happy, but if you really want to send a man into transports of
joy, just whisper these two words to him: Tonka Toy.
Tonka Toys were the virtually indestructible metal toy
trucks and construction equipment that spelled the pinnacle of a certain kind of butch
boyish wonder. They were large -- for toys -- but what made them really special was that
they were small representations of really big things, like dump trucks, 12-cylinder
Caterpillar bulldozers, hydraulic backhoes, cement mixers, and car-carrier semi-trucks.
Jewel-like recreations of the massive toys the big boys get to play with goes straight to
the magic spot of a young man's soul the way Bolivian marching powder goes straight to a
slightly older man's . . . well, I guess you ladies know about that, too.
Which probably explains the goofy grins guys get when they
see the Monolithic Sound PA-1 line-stage preamplifier and HC-1b power supply. They are
tiny at 8.5"W by 6"D by 2.5"H, but they're also solidly built metal boxes
with thick faceplates, high-quality cabinetry, and the same black and brushed aluminum
livery of so many of the big guys in the high end. They're so cuuute! guys will
croon -- but if you listen carefully as they turn the knobs and flip the switches, you
might hear the ghostly echoes of their much higher-pitched inner voices going vrooom
vroom vroom.
And like the Tonka Toys we all still love -- deep in their
hearts, these small-scale wonders mean business.
If little else, the brain is an educational toy
Monolithic Sound, Inc. is the creation of Greg Schug. Schug
started out in the film industry, where his work on soundtracks piqued an interest in
audio reproduction. In 1979, he was hired by Infinity Systems to help Bascom King design
HCA hybrid class-A amplifiers and the Infinity Reference System (IRS). Schug created
Monolithic Sound to manufacture the HCAs and before he knew it, Monolithic was a major
player in the OEM design and manufacture of subassemblies for a bunch of better-known
companies, including Genesis, PS Audio, and Vandersteen.
Dusty Vawter was Audio Alchemy's QC/Customer Relations
manager, where he made quite a name for himself because of his obvious concern for
customer satisfaction and his innovative solutions to catastrophic systems failures. It
seemed as though everyone who ever dealt with him became an instant fan -- his name
was almost religiously invoked on quite a few audio bulletin boards. In 1997, he left
Audio Alchemy to join Greg Schug in an ambitious project: to produce a complete line of
original Monolithic audio products that combined extraordinary sound quality, impeccable
construction, and year-in/year-out reliability with a novel concept -- affordability.
Sure, it had been attempted before, but they meant to go out and do it. (Men will
recognize that sort of can-do optimism as pure Tonka.)
The company's first three products (the PA-1 and HC-1b are
joined in the line by a phono section, the PS-1) have been on the market for a while now
-- and they're about to be joined by several power amplifiers -- but most people still
haven't realized they are available.
The PA-1 and HC-1b are, as I said, small. The
"passive/active" preamplifier offers three controls on its faceplate: a
four-position source-selecting knob, a three-position lever switch (source/mute/monitor),
and a large volume knob with "0db" printed on the faceplate's 12 o'clock
top-center position. A power-indicating LED is located in the center of the front panel.
Around back, the gold-plated RCA sockets are laid out in
two double rows of four on either side of a centrally mounted five-pin DIN connector
supplying the unit with 16V AC from its outboard power supply (or the upgrade HC-1b). To
the DIN plug's left are two main outputs and a tape-out and tape-in set. On its right are
four pairs of source inputs. Despite the PA-1's 8" width, there's sufficient real
estate for all but the bulkiest RCA connectors. In addition, the six-pound weight of the
unit will prevent it from orienting itself into what Tom Norton dubbed the
"pre-launch position" should you attach it to a set of especially stiff cables.
The PA-1 costs $499 USD.
The HC-1b appears to be a plain black box. On its rear
panel it sports an IEC power-cable socket and the hard-wired five-pin DIN-terminated
umbilical. It employs three stages of AC filtration on incoming power and two 1.5A
transformers (one to a channel). The umbilical is shielded. It sells for $279.
My God! FAO Schwartzkopf
In designing their new line of components, Dusty and Greg
had a secret weapon in their arsenal: Dusty's fiendishly clever inspiration for a
passive/active preamplifier, which sounds like an oxymoron and requires a word of
explanation.
A line-stage preamplifier, of course, serves two primary
functions. It allows audiophiles to connect multiple source components and switch among
them. So, if you have a CD player, an FM tuner, a cassette deck, and a turntable, a
preamplifier allows you to choose which one to listen to and it also allows you to adjust
your power amplifier's output. (Of course, if you have a turntable, you'll also need a
phono section, but that's another review.)
Now let's say you don't have four source components. Let's
say you just have one -- do you still need a preamplifier? Some people would argue that
you don't, especially if your CD player (for instance) has variable output. It's simple,
these folks would say, the CD player has sufficient voltage to drive the amp, so who needs
a preamp?
The logic seems unassailable -- all the more so since I
can't mount a rational counter-argument. Many people do exactly this, and many of them are
ecstatically happy with the way that sounds. However, in practice, I have never found this
type of setup to actually sound better than one using a well-designed preamplifier, no
matter how devoutly I want to believe that the simpler a system is the better.
Which brings us to the second thing about preamps: There's
another split in design philosophy over what kind of preamplifier sounds best. Like
I said, many contemporary line-level components now output a signal of sufficient strength
to drive a power amplifier, so many audiophiles feel that adding an active circuit that
amplifies that signal is merely a carry-over from the days when phono cartridges needed to
have their output amplified to a level that matched line-source components. These
audiophiles believe that passive preamplifiers -- preamps that eschew gain circuitry --
are better, in fact, than those that process the signal and boost it.
Naturally, life isn't really that simple. For one thing,
many interconnects add capacitance, which has a very decided effect on the sound
transmitted through them, especially if the cables are longer than, say, a few feet.
(Cable capacitance "slows down" and interferes with the signal being transmitted
-- chiefly by rolling off the high frequencies. A stronger signal is better able to
overcome the cable's tendency to store energy than a weak one.)
Complicating matters even more, the potentiometer used to
control volume is a capacitive element and the sound transmitted through the cables can
change based on the capacitance of each volume setting, so as the sound gets louder and
softer, it also changes its harmonic integrity.
But even if you only employ a very narrow range of control
settings and keep the connecting cables short, you cannot create a sound louder than that
dictated by the source component's maximum output -- and with some music and in some rooms
that might not be enough to sound realistic.
Again, I like the idea of a passive preamp, and I
even like the sound I have achieved with many passive preamps over the years, but
ultimately I always return to active preamplifiers because sometimes you need to drive an
amp harder than the source component alone can -- and because extra gain adds bass
definition and impact, no argument about it. Gain, I maintain, is seductive.
But what if you could have a preamplifier that operated as
a purely passive device except when you needed the extra gain for oomph or long cable runs
or capacitive interconnects? Or to put it another way, what if you could have a
preamplifier that was passive except when it wasn't?
Love and all his pleasures are but toys
That's the PA-1 in a nutshell. When the audio signal
enters, it splits and runs parallel through the preamplifier. One leg runs straight
through the volume pot (a custom-built ALPs unit) and from there to the preamp's main
outs. The other leg of the signal routes through a simple but well-implemented class-A,
dual-mono gain section, which then goes to the specially designed volume control and is
fed into the pot at the 0dB point (if you twirl the knob, that position is marked by a
palpable "notch" -- a detent actually). The active stage adds about 6dB of total
gain to the PA-1's output -- not a lot, as active preamps go, but (obviously) far more
than any passive device.
Nothing could be simpler to operate than the PA-1. If it's
plugged in, it's on. You can connect up to five sources (remember that tape loop?) and
switch among them. Almost everyone knows how to adjust a volume control -- so no surprises
there.
Some folks may miss remote control, but they may not be
considering all the possibilities -- given its small size and ability to drive long
cables, you can put the PA-1 within reach of your listening spot, even if a full-sized
preamp wouldn't work there. Of course, if you must have remote, the PA-1 is not for you.
I spent some time with it earlier today, using it in
exactly that way -- although with a twist. I've been playing around recently with a 40GB
portable MP3 player capable of ripping at 320kbps (which is a different kettle of fish
entirely from 128kbps). Even at 320kbps, you have access to hundreds of hours of music in
a case not much bigger than the original Walkman. I have connected the player to my main
stereo, but that places it across the room, which makes it hard to skip the occasional
song I'm not in the mood for when I have it on random play -- so I connected it to the
PA-1 next to my comfy chair and ran the tape output 20' to the Ayre K1-x at the other end
of my living room. Problem solved -- the PA-1 drove the cable beautifully and I was able
to make all the program adjustments from my seat.
Used as a conventional preamp, the unit also performed
extremely well. I've used it in a variety of systems ranging from the modest (Blue Circle
Music Pumps and Roman Audio Centurions, driven by my Musical Fidelity Nu-Vista 3D CD
player) to the lavish (Dynaudio Evidence Temptations, Aloia ST 15.01i, Audio Research CD3)
and it was right at home making music in them all.
When used as a passive preamp, the PA-1 sounds clear, fast,
and pure. In other words, it was the perfect poster boy for preamp passivity. Driving the
Music Pumps/Centurion combination (using short runs of the reasonably low-capacitance
Stereovox SEI-600 interconnect), it had bass -- complete with bass impact -- and a lively
dancing grace that kept the music involving and uncolored.
In my largish room, listening to the passive PA-1 with the
Roman Audio loudspeakers and the Music Pumps, I had no problem attaining my normal
listening levels. Not only was the speed and transparency of the sound completely
satisfying, but the music's dynamic changes and shadings were realistically nuanced,
lending a solidity and believability to the system's presentation.
This was less true with the harder-to-drive Evidence
Temptations -- in fact, the passive performance was clearly not making those babies sing
at all. Thanks to Dusty's parallel performance concept, all it took was the addition of a
little gain and, suddenly, the Wailers' Tuff Gong mix of Catch a Fire [Island/Tuff
Gong 314 548 635-2] was pumpin' out some serious Jamaican riddum. The change was
amazing -- below the 0dB detent, it was bodiless and somewhat limp; just a skoontch
past 0dB and it sprang to life as big and dynamic as a marching band.
But as good as this was, it actually got better when I
substituted the HC-1b for the preamp's stock power supply. Whoooeeee and gosh.
Among other things, the improvement beautifully illustrated
the uselessness of an audition that lacks context. Because the addition of gain solved
several problems in the system's sound when driving a more difficult load, it sounded like
an across-the-board improvement. Directly comparing the sound of the PA-1 with the
standard power supply and with the HC-1b highlighted some problems I hadn't noticed. Well,
highlighted them by removing them.
The sound of the active PA-1 alone is neither as
full-bodied nor transparent as when the HC-1b powers it. Of course, more than 20 years
ago, the late Julian Verecker was demonstrating how much difference stiffening a power
supply could make, but it still hasn't penetrated audiophile awareness as strongly
as many other bits of original audio wisdom. We tend to think of a circuit's sound as
being resident in the signal path. But the power supply can make a night-and-day
difference -- and in this case, it surely does.
The difference is like getting the focus right on a Sinar
4" by 5" camera -- with those babies, you can move the film plane of the camera
in relation to the vertical plane of the lens. So, if the lens is aligned at 90 degrees to
the floor and you aim the film plane at the center of the image, the field of focus is
narrowed and only the center of the film plane is in focus -- move away from the center
and the picture is reduced to a blur. Align the two planes just so, and pop,
everything appears sharply focused and detailed. It's not a change in perspective, like
you get aligning two magnifying lenses on a telescope; it's a complete change in detail
throughout the area being reproduced. Putting the HC-1b on the PA-1 reveals all the areas
of the sonic picture that weren't in perfect focus before.
Transients, such as the huge bass-drum thwacks, and
orchestral tuttis on the Barenboim/CSO Le Sacre du Printemps [Teldec 8573 81702-2],
start and stop with greater alacrity, while instrumental voicings within the orchestral
whole sound more discrete and less "blobby." That sounds vague, but what I'm
trying to say is not so much that you hear each instrument, since, of course, that's not
what orchestral playing is about, but more that sections and ensembles blend amongst
themselves, while retaining their separate identities, rather than becoming
indistinguishable parts of a homogeneous massed orchestral sound hybrid.
I need to be careful here in a couple of different ways. If
your system does not require gain at all, you won't really reap any audible benefit from
adding the HC-1b (well, maybe in a couple of highly specific instances, but not really).
Also, as much of an improvement as the HC-1b makes, I was pretty happy with the sound of
the stock PA-1, especially within its price range.
The site of the true bottomless financial pit is the toy
store
Adding the HC-1b made a tremendous difference in the sound
of the active PA-1 and the $778 combo was capable of putting more expensive preamps to
shame, but even in this age of line-level sources, a truly great preamp does something
special. Why should you pay a fortune for a preamp? Darned if I can explain it, but the
$6750 Ayre K1-x remains a component apart from all others when it comes to setting preamp
standards. If there's another preamplifier that performs better, I haven't heard it -- and
what do I mean by perform?
The K1-x has less "sound" than anything I know,
yet every system I've constructed around it has one thing in common -- it has sounded
better, livelier, truer, more full of that "jump factor," as Sam Tellig used to
call the infinite sense of rediscovery one gets from live music. And, while I'd love to
relate that the Monolithic PA-1 at $750 was the preamplifier that was the exception to
that rule, it just wasn't so.
The Ayre's presentation seemed dynamically unrestrained --
the PA-1 somewhat restricted in comparison. The Ayre sounded (well, it did!) airier
and music sounded weightless and unfettered. The PA-1 was a tad whiter and,
simultaneously, less vivid. And the Emma Kirkby/AAM recording of Mozart's Exultate
Jubilate [L'Oiseau-Lyre 411-832-2] had an inner illumination, a sort of nacreous
shimmer (think of the mildly lustrous translucence of an uncooked kernel of Arborio rice)
that the firefly at dusk illumination of the PA-1 (as pleasant as it was) just couldn't
equal. Dabnabbit.
But let's get real here, the Ayre costs $6000 more
and the Monolithic PA-1 didn't embarrass itself either. Like the Tonka Toys of my youth,
it was more than a symbolic representation of the real thing, and it was very, very like
the real thing. It was all a matter of scale.
A more rational comparison, of course, would be to the $499
Blue Circle Music Purse, I reviewed several weeks ago. In terms of function, the two units
are almost twins. Comparing the active PA-1 to the Music Purse revealed more similarities
than differences, actually. Both are slightly warm sounding -- as opposed to bright or
harsh. And that warmth tends to obscure a very small amount of detail. On the other hand,
both preamps are quite engaging and never sound offensive or strident.
But if warmth and amiability sound like qualities you don't
want, the PA-1 also offers passive operation, with its sense of transparency and
neutrality. Choices are good.
And -- only you can say if this is a benefit or a bug --
the PA-1 looks like other audio equipment. The other kids won't laugh at you for
playing with it.
As the creative adult needs to toy with ideas, the
child, to form his ideas, needs toys
Greg Schug and Dusty Vawter ought to be pretty proud of
themselves. The Monolithic Sound PA-1 Preamplifier and HC-1b Power Supply are true
high-end audio products masquerading as toys. Well, maybe not masquerading so much as
evoking the same sort of pleasure and wonder.
But make no mistake, they are the real thing. The stock
PA-1 offers superb construction and passive preamp performance of the first water -- for
just shy of $500. Its small size makes it a natural for multi-room systems and for dens,
studies, bedrooms -- anywhere you want high-quality switching and loudness control. And
its innovative passive/active operation means you can use it in a huge variety of systems.
Not too shabby.
If you need the added gain it can provide, you'll
undoubtedly want to add the HC-1b, which will make a good product much better than the
power supply's $279 price sticker might suggest. Go ahead and buy the stock unit. After
you've had it for a while, audition the HC-1b -- it almost certainly won't be going back
to the store.
Go ahead. Try the PA-1. Play with it and you'll be hooked.
Ummm, I meant play it and you'll be hooked.
Vroom, vroom.
...Wes Phillips
wes@onhifi.com
Monolithic Sound PA-1 Preamplifier and HC-1b
Dual-Mono Power Supply
Prices: $499 for PA-1; $279 for HC-1b
Warranty: One year parts and labor
Monolithic Sound
515 Sandydale Road
Nipomo, CA 93444
Phone: (805) 929-3251
E-mail: info@monolithicsound.com
Website: www.monolithicsound.com
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