Nakamichi IA-1z DTS Integrated Amplifier
High End Home Theater
by Jim Bray
high end audio leanings don't have to worry as much about the inevitable
compromises between pure aural ecstacy and home theater delights.
That's because Nakamichi's
IA-1z DTS Integrated Amplifier has arrived on the scene.
The IA-1z DTS is definitely
a high end component - it sells for about $2600US - yet rather than eschew
the "hated video" aspects of the home theater and concentrate only on
sonic superiority, it embraces both sides of the equation fully.
Balancing audio quality
with the input/output and surround sound requirements of today's home
theater is a tricky thing to accomplish. There are concessions to be made
when packing all that stuff into a single component - which is why many
high end audio enthusiasts look down their noses at things like A/V receivers,
which provide "all in one" solutions to the masses who can't afford -
or can't be bothered with - high end separate components.
But, as Nakamichi
shows, it can be done if you really want to do it.
The Japanese manufacturer,
whose AV-10 receiver we reviewed
(and loved!) earlier, has taken a "no prisoners" approach to this amplifier.
Not only does it offer Dolby Digital and DTS decoding, without all the
"digital sound field" surround sound gimmicks available on many components,
but it's a top notch audio component as well, which will put it in good
stead with the audiophiles among us.
The IA-1z DTS is a
handsome unit, in a plain sort of way, without a lot of bells and whistles.
It tips the scales at just shy of 40 pounds, puts out 100 watts per channel
in stereo mode and 80 watts x 5 channels in surround mode.
The IA 1z DTS' display
is simple and functional, and would you believe it comes with two remote
controls. Two? You bet.
The main unit is
a learning universal remote you can teach to operate just about any other
component you own. The second remote is small and only operates the main
functions like power, volume, etc. and is primarily designed for use in
a second room when you're exploiting the IA-1z DTS's multi-room capabilities.
We found the secondary remote extremely handy right in our home theater,
though, next to the big easy chair, while the main remote stayed on the
coffee table in front of the couch - with the rest of the remotes. This
allowed people in different parts of the room to operate the Nak independently
of each other, which was a nice bit of flexibility - most of the time.
There was the odd time when having two remotes on hand led to remote control
wars, however, as two people argued with their fingertips about how loud
a particular programming source should be played.
Still, at least we
Programming the universal
remote is fairly straightforward, though it's more involved than merely
punching in a code. The IZ 1z DTS uses the type of learning remote that
requires you to point the source remote at the top of the Nak's, and press
corresponding buttons on both units. This is a bit more work, but it's
also a lot more flexible than the code-based remotes.
The remote isn't an
ergonomic masterpiece by any means, featuring multiple rows of virtually
identical buttons with tiny labelling. It's no worse than much of its
competition, however - and at least it's flexible.
The front panel is
clearly laid out, with audio/video source selector buttons mounted in
a pair of rows on the left (they're big and easy to find, too) and the
surround mode/speaker controls to their right. Setting up the speakers
is easily accomplished without even glancing at the manual, and a bunch
of LED's let you know upon which channel you're wreaking havoc.
Later, when you're
actually using the amp, these LED's indicate which channels the signal
source is using, from two channel stereo to the 5.1 configuration of the
digital surround playback systems.
You get a lot of flexibility
in configuration of the amp, too, including different modes to optimize
the amp for different speakers. You can use the test tones to set up your
surround configuration, and even set the delays independently for the
center and rear channels.
A dynamic range compressor,
accessible on Dolby Digital programming sources, makes the system more
conducive to late night viewing (when the kids are asleep) and you can
also adjust the low frequency effects signal.
Rear panel connectors
included on "The Nak" include just about all the inputs and outputs you're
likely to need, save possibly a turntable. Each video source has "S" and
RCA jack connectors, and all the jacks are gold plated, which is a nice
The five sets of speaker
terminals are of the big "binding post" type that let you hook in just
about any connector you may have (we used banana plugs). Video connectors
include LD, DVD/DBS (though we wish these were separate), VCR (record
and play, naturally), and TV/Aux (again, we'd prefer separate, but can
live with this configuration). There's also an extra video output to the
the TV monitor itself.
include CD, Tuner (integrated amps don't have built in tuners), and two
sets of Tape Rec/Play.
To sweeten the deal,
Nakamichi throws in two optical and three coaxial digital inputs, one
of which is meant to take the output from an AC-3 decoder-equipped laserdisc
player. You also get a set of remote outputs, which can be used to send
your favorite tunes to another room.
All of these connectors
are grouped logically and are easy to find and use.
Another set of outputs
is for the preamp stage, so you can expand the system by adding different
power amps down the road. This would waste the amps built into the unit,
and it would seem to make more sense just to buy Nakamichi's CA-1 Audio/Video
Control Amp if you want to mix and match amplifiers.
But, hey, the feature's
there if you want it.
says the IA-1z is basically the CA-1 and its companion PA-1 power amp
built into a single unit.
Life with the Nakamichi
Using the amp is very
straightforward, and the sound is very, very clean and easy on the ears.
We could find no harshness or unpleasantness in its reproduction, and
were very, very impressed with its imaging all around the room.
For example, there's
a scene in the movie "Dragonheart," which we have in DTS audio, in which
Dennis Quaid and the scaly beast are travelling across the countryside,
the dragon flying in circles around Quaid as they converse. The Nakamichi
placed the dragon's movement beautifully, with its voice and the flapping
of its wings circling the room with the character. It was an exhilarating
home theater experience that reminded me of the nearly forgotten heyday
of four channel quadraphonic sound.
The amps inside the
IA-1z are what Nakamichi calls "Harmonic Time Aligned" which, as a non-technical
publication, we aren't going to explain in detail. Nakamichi says it aligns
the primary signal (the good stuff you want to hear) with the harmonic
distortion so it all arrives at your ears simultaneously, which they say
makes the overall sound quality much more pleasant. We cannot quibble
with the pleasant sound of this amp; it is indeed, very pleasant.
On the other hand,
we found that on our reference speakers (older DCM Timeframes they'll
have to pry from our proverbial cold, dead fingers) the IA-1z DTS didn't
offer a lot of "oomph" at virtually any volume, so we could never get
it to play as loudly as we'd have liked (which, admittedly, is really
loud!). This was undoubtedly a mismatch between the Nak and the relatively
inefficient DCM's. If we'd had a pair of Klipsch, for example, on hand,
I reckon we'd have been very pleased indeed.
the AV-10 receiver we tried earler (which isn't as high end as this amp)
seemed to be a better match for our DCM's. Go figure.
You can control the
Nak via onscreen menus or, if you prefer, you can shut 'em off and wing
it solo. I prefer not having these displays when I'm watching something,
so was glad for the flexibility.
I had one other problem
when using this beautiful amp, and it was a strange one. When playing
an audio CD in a DVD player, I had to shut off the Dolby Digital setting
manually (not a big deal, as long as you remember to do it), but the problem
came when going back to play a DVD. If I forgot to activate the Dolby
Digital setting manually before the disc started playing, this gawdawful
"digital motorboating" noise would be generated through the speakers.
Nakamichi says it's
only a problem with AC-3-encoded discs (DTS ones, it says, are automatically
sensed - and I'll have to take their word for it 'cause I forgot to check
with our DTS discs before sending the unit back!), but most DVD's come
with AC-3 audio, not DTS, so this isn't much consolation.
A minor problem, but
not something I expected to see in a $2600US amp.
It just goes to show
that nothing's perfect under the sun.
Our overall impresssion
of Nakamichi's IA-1z DTS is that it's a solid, well designed and built
unit that offers audiophiles all the home theater gadgets one needs, without
the bells and whistles that may make a nice sales pitch but which don't
do a lot for your actual enjoyment (and which you'll probably never use
once you've tried them once) and which can compromise the ultimate audio
fidelity of the system. The amp is easy to use, and it offers beautiful
We'd like to have
seen more power for our home theater application (since our speakers are
lovely but inefficient, we're forced to subscribe to Tim 'the Toolman'
Taylor's "MORE POWER!" school of thought here). That said, however, there
are many people who either have very efficient speakers or who aren't
interested in peeling the paint from their walls.
To them, we say this
Nakamichi is well worth a serious look.If they can afford the sticker
price, they just may find the IA-1z a marvelous unit for their lifestyles.
Analog Audio Section
Inputs: 9 (CD, Tuner, Aux, Tape 1, Tape 2, LD, DVD/DBS, VCR, TV/Aux)
Recording Outputs: 3 (Tape 1, Tape 2, VCR 1)
Main Output: 6 channels (Front L/R, Center, Rear L/R, Subwoofer)
Remote Output: 2 channels (L/R)
Input Sensitivity/Impedance: 250 mV/47 kohms
Rated Output Level/Impedance
Main output: 1 V/1 kohm
Remote Output: 500 mV/1 kohm
Recording Output: 250 mV/1 kohm
Subwoofer Output: 1.65 V/1 kohm
Maximum Main Output Level: 8V
Total Harmonic Distortion: Less than 0.01% (20 - 20,000 Hz)
Frequency Response: 10 - 50,000 Hz +0, -3 dB
Signal-to-Noise Ratio: Better than 90 dB (A-WTD, input shorted)
Channel Separation: Better than 70 dB (1 kHz, input shorted)
Digital Audio Section
Inputs CD: 1, Coaxial
LD (AC-3 Digital): 1, Coaxial
LD (PCM Digital): 1, Coaxial
DVD/DBS: 1, Coaxial or Optical (selectable)
(AC-3 Digital/PCM Digital)
Input Impedance: 75 ohms
Maximum Output Level (After D/A conversion, at 0 dB)
Main Output: 7 V/1 kohm
Recording Output: 2 V/1 kohm
Subwoofer Output: 8 V/1 kohm
Total Harmonic Distortion: Less than 0.01% (1 kHz, at 0 dB)
Frequency Response: 10 - 20,000 Hz +0, -0.5 dB
Signal-to-Noise Ratio: Better than 100 dB
Dynamic Range: 95 dB
Channel Separation: Better than 90 dB
Output Level Control Section
Gain Range: -75 dB to 0 dB (level 0 to 100 max.)
2 dB-Steps: -75 to -55 dB (level 0 to 10)
1 dB-Steps: -54 dB to -35 dB (level 11 to 30)
0.5 dB-Steps: -34.5 dB to 0 dB (level 31 to 100)
Audio Mute Default Setting: -75 dB (level 0)
User Adjustable Range: -75 to -35 dB (level 0 to 30)
Composite video: 4 (LD, DVD/DBS, VCR, TV/Aux),
Coaxial S-Video (Y/C) : 4 (LD, DVD/DBS, VCR, TV/Aux),
S-Video jack Outputs: Composite video: 3 (VCR, Monitor, Remote)
S-Video (Y/C): 3 (VCR, Monitor, Remote)
Video Signal Type: NTSC
Video Signal Level/Impedance:
Composite video: 1 Vp-p/75 ohms
S-Video: 1 Vp-p/75 ohms (Y-Signal) 0.286 Vp-p/75 ohms (C-Signal)
Composite video: 5 Hz - 10 Mhz +0, -3 dB
S-Video: 5 Hz - 10 MHz +0, -3 dB
Dolby AC-3/Pro Logic Section
Speaker / Subwoofer Mode Settings and Signal Characteristics
Front L/R Channels Speaker Mode:
Large: Full range signal
Small: High pass filter active (fc: 80 Hz, 12 dB/oct)
Center, Rear L/R Channels Speaker Mode:
Large: Full range signal
Small: High pass filter active (fc: 80 Hz, 12 dB/oct)
None: Phantom mode for Pro Logic
Subwoofer Channel SW Mode:
Normal: Low pass filter active (fc: 80 Hz, 12 dB/oct) + LFE signal (AC-3
LFE only: Only LFE signal is output
No: No subwoofer output
Channel Level Calibration Range
Front L/R: -3 to +3 dB
Center: -10 to +10 dB
Rear L/R: -10 to +10 dB
Subwoofer: -10 to +10 dB
Delay Time Calibration Range
Center: 0 to +5 ms (AC-3/Pro Logic mode)
Rear L/R: 0 to +15 ms (AC-3 mode) +15 to +30 ms (Pro Logic mode)
System Remote Contorl Section
Remote Sensor Input: 1-1/8" stereo mini jack for external IR sensor
System Remote Outputs: 1-1/8" stereo mini jack for controlling Nakamichi
cassette decks/CD players
Power Amp. Remote control Output: 1-1/8" stereo mini jack (12V DC/120
Outputs: 5 speaker terminals (Front L/R, Center, Rear L/R)
Continuous Sine Wave Power Output: 80W x 5 (8 ohms, five channels driven,
20-20,000 Hz, 0.1% THD)
100W x 2 (8ohms, two channels driven, 20-20,000 Hz, 0.1% THD)
Dynamic Output Power: 102W x 5 (8 ohms, five channels driven)
Power Bandwidth: 10-30,000 Hz (Half rated power, 0.1% THD)
Output Impedance: Less than 0.1 ohms
Total Harmonic Distortion: Less than 0.1% (Rated power, 20-20,000 Hz)
Intermodulation Distortion: Less than 0.1% (Rated power, 60 Hz: 7 kHz,
Output Current Capability: 10 A continuous, 20 A peak (Per channel, five
Power Supply: 600W R-core transformer, 44,000µF total filter capacitance
General Power Source: 120V AC, 60Hz 230V AC, 50Hz (According to country
Power Consumption: 860W
Dimensions*: 430 (W) x 170 (H) x 398 (D) mm 16-15/16 (W) x 6-11/16 (H)
x 15-11/16 (D) inches
Weight: Approx. 17.5 kg/38 lbs. 8 oz.
Supplied Accessories: IEC R6 (size AA) batteries for RM-1m/RM-1s (4)
AC power cord (1)
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