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)
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