Nakamichi ZX-7 ()

Name: Nakamichi ZX-7
Brand: Nakamichi

A high-end stereo cassette deck with manual calibration and a discrete three-head design.

Overview

The Nakamichi ZX-7 is a stereo cassette deck made by Nakamichi, . It was priced at ¥188,000 in Japan around 1981 and $1,250 in 1983. It has a discrete three-head system and manual calibration for azimuth, level, and bias, so the tape alignment can be set precisely. It has Dolby B and C noise reduction, a 50 dB LED peak level meter, and a digital tape counter. It was built for audiophiles, supports ZX, SX, and EXII tape types, and takes the optional RM-200 remote control.

Specifications

Track format	4-track 2-channel stereo system
Heads	3 heads (1 erase, 1 record, 1 play)
Motor (for tape drive)	For capstan : PLL servo motor; For Reel : DC Motor
Tape speed	4.8cm/s
Wow and flutter	0.04% or less WTD RMS; 0.08% or less WTD Peak
Frequency response (recording level -20dB)	20 Hz ~ 21 kHz ± 3 dB (ZX Tape); 20 Hz ~ 20 kHz ± 3 dB (SX, EXII tape)
Overall SN ratio (400 Hz, 3% THD IHF A-Wtd rms)	Dolby B NRon : 66 dB or more (70 μ s, ZX Tape); Dolby C NRon : 72 dB or more (70 μ s, ZX Tape)
Total Distortion Factor (400 Hz, 0 dB)	0.8% or Less (ZX Tape); 1.0% or Less (SX, EXII tape)
Erasure rate	60 dB or More (100 Hz, 0 dB)
Channel separation	37 dB or More (1 kHz, 0 dB)
Crosstalk	60 dB or More (1 kHz, 0 dB)
Bias frequency	105kHz
Input Sensitivity / Impedance	Line : 50mV/50k Ω
Output Level / Impedance (400 Hz, 0 dB, maximum output level)	Line : 1V/2.2k Ω; Headphone : 45mW/8 ohm
Dedicated DC output for black box series	± 10 V, 125 mA max.
Power	100 VAC, 50Hz/60Hz
Power consumption	40W max.
External dimensions	Width 450x Height 135x Depth 300 mm
Weight	Approx. 9.5 kg

Design

The ZX-7 uses a frequency-distributed double capstan system. The chassis is aluminum alloy with a plastic outer plating. The three heads are all separate. The P-8L playback head has a quartz laminated core and a 0.6-micron gap. The R-8L recording head has a 3.5-micron gap. The E-8L erase head has ferrite and Sendust cores. The recording and playback EQ circuits use a double NF design, with negative feedback applied to an electrolytic capacitor, and the recording amplifier is directly coupled to the head. An N-MOS 4-bit microprocessor controls the manual calibration for azimuth, level, and bias. The front panel has a 16-segment LED peak level meter (-40dB to +10dB), a digital LED tape counter, and a master fader switch for 6-second or 2-second automatic fade. A voltage selector on the rear panel lets it run in different regions.