Mcintosh c2200 schematic
“I
t took long
enough,” as I
said to Larry
Fish and Roger Stockholm.
McIntosh Labora-
tory
1
has waited nearly
40 years to introduce
its first totally new
tube preamp since the
C22, which was in
production from 1963
to 1972. I was in college in 1963—more
or less penniless, drooling over Mac gear in the windows of a
shop in Providence, Rhode Island.
Better graduate. Get a job. Make some
dough. Buy some Mac tube gear.
Oops. Too late.
By the time I could afford new Mac
tube gear, in the mid-’70s, Mac was
making only solid-state. I could have
bought used. Probably should have.
Everyone then, though, was saying halleluiah, good-bye tubes, good-bye trouble, hello solid-state. Len Feldman,
Julian Hirsch —even our own guru,
J. Gordon Holt. You don’t argue with
the experts, right?
I have long lusted after McIntosh tube
gear, so I was delighted when, in the early
1990s, McIntosh revived their MC275
power amp —the very amp I wanted to
own back in my college days—and
then, several years later, the C22 preamp. These were reissues—close, if
not exact, replicas of the originals. I
never did try the C22 reissue, but the
MC275 Commemorative remains a
staple of my collection.
For the company’s 50th anniversary, in
1999, McIntosh commissioned Sidney
Corderman (who engineered the original and reissue of the MC275) to design
the MC2000 Commemorative power
amp. The amp was about a year late and
went for $15,000. The MC2102 power
amp followed, for a mere $6000—also
designed by Mr. Corderman.
Now, of course, McIntosh dealers
and customers wanted a tube preamp.
Hence the $4500 C2200, meant to be
matched with the MC2102 or the
MC2000. (For MC2000 owners, a special edition of the C2200, with goldplated endcaps and knobs, is available.)
“The C2200 is currently our bestselling preamp,” Larry Fish told me.
You’ve met Larry before. He’s
McIntosh’s vice president of product
planning.
“Selling more briskly than solid-state,
eh?”
I had to rub it in. Larry is so solidly
solid-state.
“We can’t make them fast enough.
We’re back-ordered.”
I had a very hearty laugh.
“I knew you’d find that amusing,”
Larry said.
“Almost as amusing as the fact that
Roger Stockholm was project engineer
for the C2200.” If anything, Roger is
even more solidly solid-state than Larry.
Or was.
Roger’s official title is senior electronic design engineer. He joined McIntosh 31 years ago, just as the last of
the original C22s was
going out of production. Naturally, he
started designing solidstate products. Roger
has been project engineer for almost every
McIntosh preamp
since the C32, in the
late 1970s. Until the
C2200, he’d never
touched tubes.
The company
teamed Roger up with
the legendary Sidney
Corderman, Mac’s Mr. Tube. For the
C2200, Sidney engineered the tube
circuits and Roger worked on the rest.
“It was a collaborative effort,” Roger
told me, involving Larry Fish and
Chris Bomba, McIntosh’s senior software engineer.
“Has Sidney turned you into a tube
believer?” I asked Roger.
“I’ve come around a bit,” he admitted. Hesitantly.
“If I had predicted five years ago that
you, Jolly Roger, would be project
engineer for a new McIntosh tube amp
for the 21st century, what would you
have said?”
“I’d have said you were crazy.”
I first met Roger three years ago,
when he and Larry delivered a
McIntosh C42 preamp for me to audition with the MC2000. Poor Roger. He
was so proud of his preamp, which was
quite nice and remains in production,
but all I had eyes for was the tube amp.
(By the way, Roger and Larry are new
hires compared to Sidney, who has been
with McIntosh Laboratory since its
founding, in 1949.)
The C2200 retails for $4500, and I find
it hard to imagine that any McIntosh
enthusiast wouldn’t want to own one —
even fans of Mac’s solid-state amps.
Tubes aren’t as troublesome as they’re
sometimes made out to be —especially
the small ones typically used in preamps. (The C2200 uses four 12AX7
and four 12AT7 tubes.) Such tubes can
last for a decade or more, and are easy
and inexpensive to replace. They don’t
give off anywhere near the heat of, say,
a KT88 or 6550 output tube.
Stereophile, May 2002
McIntosh C2200 tube preamplifier
1 McIntosh Laboratory, Inc., 2 Chambers Street,
Binghamton, NY 13903. Tel: (607) 723-3515. Fax:
(607) 723-1917. Web: www.mcintoshlabs.com.
For the McIntosh C2200,
Sidney Corderman
engineered the tube
circuits and
Roger Stockholm
worked on the rest.
Electronically Reprinted from May 2002
Sam’s Space
Sam Tellig
The C2200’s front panel measures
17" wide by 7
1
⁄8" high, and the preamp
is 14" deep and weighs 26.75 lbs. The
high-level (or line-level) circuitry uses
two 12AX7A tubes and two 12AT7A
tubes. Ditto for the moving-magnet
phono stage: two 12AX7As, two
12AT7As. The phono tubes come on
only when you select the phono input.
If you don’t use the phono input, you
won’t be burning tubes for naught.
Because the C2200 is a Mac product, there’s every user-friendly feature
you could dream of, as well as features
you couldn’t dream of but might actually use. The MM phono stage is standard — you don’t pay extra. There’s a
Mono switch. There are Bass and
Treble tone controls.
I asked Roger and Larry who’s buying the C2200.
Not just tube-amp customers, it turns
out, but owners of Mac solid-state
amps, too. Roger Stockholm, erstwhile
solid-state stalwart, explained:
“You can get your tube sound in the
preamp and then you can have bang for
the buck with a solid-state power amp.”
“Tube sound? So there is a tube
sound?”
“Larry warned me I was in for a terrible ribbing.”
Roger has come around…a little.
The C2200 has a busy rear panel.
There are six pair of outputs —three
balanced, three unbalanced. Mac
knows many of its customers are into
multiroom installations, so the C2200
can be configured to control a second
power amp in a nearby room. The extra
outputs might be useful for devices
such as powered subwoofers, too. You
won’t go wanting.
There are four pairs of balanced
(XLR) line-level inputs and six unbalanced (RCA) line-level inputs. And if
you reconfigure the phono stage to be
line-level, you’ve got seven available
RCA line-level inputs.
The C2200 is not fully balanced from
input to output. Not that this matters
much, because the preamp is so quiet.
Larry recommends using balanced connectors with long cable runs—say, from
your preamp to power amp. Any noise
the cables will pick up will be nixed by
common-mode rejection.
The phono input can be reconfigured
by the user to serve as an additional linelevel input. There’s a headphone jack,
using an ICE buffer that lowers the high
impedance of the line-stage tubes.
There’s full remote control. And you
can trim the inputs so the line levels
match in loudness.
At first glance, a visiting manufactur-
er of tube gear mistook the C2200 for a
power amp. That’s easy to do —there
are twin McIntosh “blue-eye” powerlevel meters. The C2200 sports the
familiar Mac glass faceplate. Labels for
the various control functions are illuminated in white on black. A digital readout displays the input selected. Few preamps look so sexy in the dark.
But…power-level meters?
Customers want them, said Larry
Fish. “We made them useful,” he hastened to add. “The meters are calibrated
so that ‘0’ represents full output at 2.5V.
If your power amp’s input sensitivity is
2.5V, then a ‘0’ reading on the preamp’s
meters will represent the amplifier’s
maximum rated power.”
“But do you really need the meters?”
“Well, on some McIntosh amps you
don’t have meters. Your MC275, for instance.”
I can see other uses for the meters —
to check the channel separation and
channel balance of your phono cartridge, for instance. You can dim the
meter lights or turn them off completely, if you like. You can also dim the digital display.
I installed the C2200 in my main system, whose AR ES-1 turntable with
SME309 tonearm and Shure Ultra 500
moving-magnet cartridge were perfect
for the C2200’s MM phono stage. For
digital, I used a Rega Jupiter CD player as
transport with the Musical Fidelity A3
24
upsampling DAC. Speakers throughout
my listening were my reference Quad
ESL-989 electrostatics.
I usually have trouble writing about
preamps. Some designs — especially less
expensive ones—have a tendency to intrude. If they’re tube, they might be
noisy. If they’re transistor, they might
impart a metallic haze. I’ve been big on
passive preamps, especially for audiophiles on a tight budget.
Surprise, surprise —the C2200 was
so quiet I thought I was listening to my
Purest Sound Systems 500 dual-mono
passive unit. I heard no noise at all
through the line-level inputs, even with
the volume cranked way up. (Of course,
I heard some noise when I selected the
phono input, but not much.)
Larry explained the C2200’s silence:
It’s the microprocessor-controlled
post-attenuator stage. He believes that
the C2200 is the only tube preamp
that has one.
“Under normal listening levels, the
C2200 is essentially a straight wire. The
post-attenuator is working full blast and
you’re listening at 12dB down from full
gain. If you need more gain to blast the
house apart, then turn up the volume
and the post-attenuator starts being
gradually removed. This allows you to
get high volume out of the preamplifier,
if you need it, but low noise under normal listening conditions. By reducing
gain, the post-attenuator reduces noise.
That’s what makes the C2200 so quiet.”
Larry paused.
“You’re an old-timer, Sam…’’
“Gee, thanks.”
“Well, you’re probably old enough to
remember preamps that had output
attenuators. There were individual volume controls for left and right channels
and then a master volume control. The
master control set the overall gain of the
preamp, and it was used to add gain
only if necessary. In the C2200, a microprocessor does this automatically and
you don’t have to think about it. As you
turn down the volume control, the
microprocessor reduces gain.”
The digital display reads from 0 to
100, but there are actually 214 volumecontrol steps. “You can set the volume
in half-dB steps.” From your easy chair,
of course. If you turn the volume up or
down very slightly, it might not show on
the display.
“A lot of thought went into the volume control,” said Roger. “We used to
have a certain taper that we used for our
mechanical volume controls. As we
introduced electronic volume controls,
we made the action linear through a
long range. But there wasn’t much
action at the lower end. Linear all the
way through wasn’t really desirable, so
we changed the way it works. That’s the
beauty of software: we build in the taper,
or curve. The C2200 basically duplicates
the old mechanical volume control.”
“That’s right,” added Larry. “The
volume-control curve was developed
over the years to come on very quickly.
What we did was replicate the mechanical action with software so that the
same rotation gives you the same result.
For instance, if you go to the three
o’clock position on the C2200’s front
panel, the volume will be as loud as it
would with a mechanical control.”
Stereophile, May 2002
Sam’s Space
At first glance,
a visiting manufacturer
mistook the C2200
for a power amp.
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