The BX-300
incorporates a wealth of original Nakamichi Technology including the Discrete
Three-Head Recording System that guarantees 20 - 20,000 Hz ±3 dB response,
perfect magnetic azimuth alignment, and maximum MOL; the Asymmetrical
Dual-Capstan Diffused-Resonance Transport that eliminates the need for pressure
pads and intracapstan guides and so has remarkably low scrape flutter and
modulation noise for superior sound clarity; and Nakamicho-quality electronics
for reduced noise and distortion. We even created a new high-inertia DD capstan
motor and servo for the BX-300 to provide the benefits of direct drive -
without its problems. If you'd rather invest insuperior performance than spend
a bundle on features you don't really need, you'll find the BX-300 made for
you.
The Discrete
Three-head System - Perfect Magnetic Azimuth Alignment Ensures 20 - 20,000 Hz
A "3-head"
deck should be better than a 2-head deck because separate record and play heads
can be individually optimized. A wide recording gap ensures full tape
utilization for optimum MOL while a narrow playback gap resolves high frequency
recordings. A 3-head deck also allows of-tape monitoring so you can check
quality as you're recording. But beware - all 3-head decks are not the same.
Most 3-head decks
use "sandwich" heads - record
and play sections are in the same housing. Once the head is made, there's no
way to align the sections. Even if the gaps are mechanically parallel, the
magnetic gaps may not be , and, without perfect magnetic alignment, response is
impaired. And, with the gaps so close together, recording flux may leak into
the playback core. In severe cases, this "crossfeed" upsets Dolby
tracking and can be heard as a preecho when monitoring compromising the
monitor's usefulness.
To Nakamichi,
"3-head" means three discrete heads - physically independent heads
that are perfectly optimized and magnetically aligned after insstallation to
ensure flat response, maximum headroom and minimum noise at all frequencies.
Our recording and
playback heads are individually shielded to eliminate crossfeed and noise
pickup. They are individually adjustable in height, azimuth, and zenith to
ensure perfect tracking, magnetic alignment and tape contact. Our mounting
system is unusually sophisticated and allows non-interacting adjustment of each
parameter for each head after installation. The results speak for themselves.
Playback head -
P2H-3L; with a 0,8 micron gap and low-loss laminated-Crystalloy core, the
P2H-3L provides smooth response to 20 kHz. A special hyperbolic geometry
virtually eliminates "contour effect" so response is uniform to the
lowest frequencies.
Recording head -
R-3L; this 3,5 micron gap head produces an extremely sharp critical zone for
maximum high-frequency response and MOL. Its laminated-Crystalloy core easily
handles the bias needed to record high-coercivity metal tape and ensures
exceptional dynamic range.
Erase head - E-4F;
with two erasing gaps, a low-loss ferrite core and high-saturation sendust
poletip, the E-4F ensures complete erasure for perfect sound clarity
Asymmetrical
Dual-Capstan Diffused-Resonance Transport Eliminates Scrape Flutter and
Modulation Noise.
Most dual-capstan
decks use identical capstans for supply and takeup. They rotate at the same
rate and concentrate wow at specific frequencies making it much more audible.
Tape tension within the "closed loop" isn't constant - the whole point of a closed-loop system - so
a pressure pad is used to maintain tape-to-head contact. With a pressure pad,
tape-to-head contact becomes erratic and, unless the pad is perfectly oriented,
the tape skews causing mistracking and azimuth error. Thus an intracapstan
guide needed.
After years of
research, Nakamichi created the "asymetrical Dual-Capstan
Diffused-Resonance Transport" - the
only mechanism that eliminates coherent wow and exercises such precise control
that neither pressure pad not intracapstan guide are required.
The pad and guide
have audible effects. As the tape passes them, it vibrates causing "scrape
flutter" and "modulation noise" which destroy sound clarity.
Modulation noise varies with recording level so it's not suppressed by
noise-reduction systems. In fact, the perceived quality of digital recording is
largely due to the absence of modulation noise. Reoving the pad and guide
virtually eliminates scrape flutter and modulation noise and allows music to
emerge with digital-like tansparency. To eliminate coherent wow, the transport
is "asymmetric", capstan are of different diameter and rotate at
different rates so they don't resonate and concentrate wow at specific
frequencies.
High-Inertia
Direct-Drive Capstan Motor and High-Precision Servo Ensure Ultra-Low Wow and
Flutter
"Direct
Drive" should be superior to belt drive because a belt can introduce speed
variations if it doesn't run true. But, direct drive mercilessly reveals motor
cogging becasue there's no compliant belt to filter it. Cogging causes high
frequency flutter that is heard but ignored in specifications. All DD decks are
not the same.
The BX-300 takeup
capstan is directly driven by an outstanding new motor that is virtually
cog-free thanks to its unusually high inertia. The motor has an exceptionally
heavy rotor with the mass concentrated at the circumference to create a
flywheel that ensures smooth rotation. It is brushless, slotless and coreless
so torque fluctuations are inherently low.
To further reduce
flutter, we extended the servo bandwidth to correct torque variations up to 1
kHz - the key element being a 160-segment frequency generator that senses speed
every 2-1/4 degrees of rotation. A careful choice of components ensures excellent
stability over time and temperaature.
The BX-300 features
Nakamichi's "Silent Mechanism" in which a microprocessor=controlled
Motor-Driven Cam replaces conventional solenoids. There's no mechanical shock
to upset head alignment and each operation is performed swiftly and precisely.
The motor actuates
three switch cams to inform the microprocessor of the current status. This
"dialogue" between mechanism and microprocessor permits sophisticated
precise control.
Nakamichi
Electronics On A Par with The Finest Preamps
To realize the full
potential of nakamichi heads and use the Dolby NR system to best advantage, we
developed new electronics for the BX-300. with distortion under 0,005%, they're
equivalent to the finest preamps.
Recording, line and
headphone amplifiers are direct-coupled and bipolar-powered for maximum dynamic
range. The Double-NF recording equalizer is directly coupled to the recording
head for low distortion and precise compensation.
Playback amplifiers
are sensitive to power supply fluctuations; our special circuitry overcomes
this problems and yields excellent Signal-to-Noise, High-gain low-noise input
FETs and Double-NF topology reduce distortion and noise and ensure perfect head
matching
A central power
supply feeds each circuit separately to eliminate noise and crosstalk.
Dolby chips are
handpicked to ensure perfect matching and realize Dolby-C's full potential.
An Array of Truly
Features for Superb Operating Convenience
Dual-Speed Master
Fader: once you've set maximum recording level and channel balance with the
BX-300's left and right Rec level sliders, you can create professional fades at
the touch of a button. Press lightly on UP or DOWN for a 4-second fade; press
and hold for a 2-second fade
Auto Repeat: turn on
Auto Repeat and the tape automatically rewinds and replays when it reaches the
end. Or, use Auto Repeat with Memory Stop to repeat playback from counter zero.
Bias Fine Tuning:
even tapes of the same general type differ somewhat in bias requirements. The
BX-300's Bias Fine Tune control allows you to adjust bias to create perfect
recordings.
Pitch Control: it's
no problem to "true" the BX-300 to your piano or other musical
instrument. Its Pitch Control allows you to alter playback speed by ±6% - one
semitone - to correct an off-pitch recording.
Dolby B/C Noise
Reduction: B-type NR reduces noise in the upper frequency region by
approximately 10 dB . C-type NR gives
you 20 dB noise reduction from 2 kHz to 8 kHz where tape hiss is most audible.
Wide-Raange
Peak-Responding Meters: LEDs accurately indicate recording level over a wide 50
dB range (-40 dB to =10 dB)
4-Digit LED Tape
Counter: referenced to "0000", this precision counter reads
bidirectionally from "-999" to "9999"
Specifications
Track
Configuration: 4-tracks, 2-channel
stereo
Heads: 1 x erase; 1
x record and 1 x playback heads
Motors
Transport
FG servo, brushless,
slotless, coraless
1 x DD motor for
capstan drive
1 x DC motor for
reel drive
Mechanism
1 x DC motor for cam
operation
Tape Speed
Recording : 1-7/8 ips (4,8 cm/sec) ±0,5%
Playback : 1-7/8 ips (4,8 cm/sec) ±6%, adjustable
Wow and Flutter
WTD Peak ; less than ±0,048%
WTD RMS : less than 0,027%
Frequency
Response: 20 Hz - 20,000 Hz ±3 dB (-20
dB recording level, )
Signal-to-Noise
Ratio
Dolby C NR : better than 70 dB
Dolby B NR : better than 64 dB
Total Harmonic
Distortion (400 Hz, 0 dB):
ZX Tape : less than 0,9%
SX, EX II tape
; less than 1,0%
Erasure: better than
60 dB (100hz, 0 dB)
Separation: better than 36 dB (1 kHz, 0 dB)
Crosstalk: 60 dB (1 kHz, 0 dB)
Biass
Frequency: 105 kHz
Input Line : 50 mV / 30 k Ω
Output
Line : 1,0 V (400 Hz, 0 dB, output control max.)/
2,2 k Ω
Headphone : 5 mW (400 Hz, 0 dB, otput control max.)/ 8 Ω
Power
Requirements: 100, 120, 120/220-240, 220
or 240 V AC 50/60 Hz
Power
Consumption: approx 27 W
Dimensions (W x H x
D): 430 x 100 x 250 mm (16-15/16" x
3-15/16" x 9-7/8")
Weight: 5,6 kg (12 lb 6 oz)
