KENWOOD KX-880D

Commentary

This is a cassette deck equipped with a newly developed DBS in addition to a SuperTLLE with an original constant current drive system.

An amorphous head has been adopted for the head part.
The head core consists of 13 layers of 45 μ ultra-thin sheets of amorphous alloy, which has excellent characteristics. This structure reduces eddy currents and extends the high-frequency range. Moreover, transmission characteristics are improved by using oxygen-free copper for the winding, and purer sound is realized.
In addition, the KX-0D uses a large amorphous head with less magnetic saturation. Since the core is large, it can generate a strong magnetic field and at the same time improve the head touch of the tape. 880 d uses a large amorphous head with less magnetic saturation.

Uses Super TLLE (twin loop linear exciter), a constant current drive system unique to Kenwood.
This system has two loops for head drive and gain control, and is directly connected to the recording head DC with ± 2 power supplies. This configuration eliminates current transmission loss in the high-frequency range, making it possible to record high-quality, thick sound. In addition, by eliminating output resistance, the dynamic range of the recording amplifier has been improved by 12 dB to 13 dB (400 Hz) compared to the conventional system. In addition, since the head drive current does not depend on the impedance change of the head, phase degradation does not occur, and current distortion caused by load fluctuation can be suppressed. Since the recording head is directly connected to DC, flat recording is possible down to the ultra-low frequency range.

It is equipped with a newly developed DBS (dynamic bias system).
In the past, high-frequency recording performance was degraded due to loss caused by eddy currents generated in the core material of the magnetic circuit, current loss in the magnetic material, and self-demagnetization caused by the head erasing data while recording by itself due to the running of the tape. As a result, when recording at a high level of 0 dB, the high-frequency characteristic suddenly drops from about 1 kHz, and when attempting to increase the frequency characteristic by lowering the recording level by 10 dB or 20 dB, the SN ratio deteriorates.
To solve this problem, Kenwood paid attention to the fact that the high-frequency component works to deepen the recording bias. When high-frequency and large-amplitude signals are received, the bias current is reduced to raise the MOL (maximum magnetic flux density), and at the same time, a unique method was added to prevent self-demagnetization. Thus, the high-frequency MOL characteristics have been greatly improved. Furthermore, since a feedback loop is not used in the circuit for reducing the bias current, there is no time constant. In addition, the high-frequency range with good sharpness is realized by following Sharp even in momentary large input signals such as attack sounds.

High-rigidity silent mechanism is adopted for the mechanism part.
This mechanism was developed by analyzing vibration modes from various angles. In the KX-880D, this mechanism has been further pursued. First of all, by simplifying the mechanism itself, a metal shaft is used as a guide for fixing the cassette, and a metal with high rigidity is used for the head base for mounting the head.
As a result, the internal disturbance of the mechanism itself caused by the motor and disturbance transmitted through the case are suppressed to the limit, and stable head touch of the tape is realized.

A newly developed low torque ripple motor is used as the drive motor.
The torque fluctuation of the motor caused unstable tape running and degraded the wow flutter. Computer analysis of the motor used in the KX-880D reduced the torque fluctuation to 1/2 that of conventional motors.
In addition, the motor drive circuit has been newly developed, and the noise component generated by the motor rotating is removed by the motor drive circuit with clear grounding, and the impact of the middle and low range sound is enhanced.

Equipped with bias calibration and rec calibration. By adjusting for each tape, it is possible to use all tapes under optimum conditions.

The recording circuit, reproducing circuit, and Dolby B/C circuit all use an op-amp type ± power supply circuit. Clear sound is realized by clarifying the ground potential of 0.
In addition, the power supply section uses a constant voltage power supply of ± Route 3 to eliminate interference between components, especially since no power ripple is applied to the recording circuit, excellent sound localization can be obtained.

Equipped with a Dolby B/C type noise reduction system.
The Dolby circuit uses a new dedicated IC and circuit to improve dynamic characteristics.

Equipped with left and right independent preset volumes and master volumes.
This allows you to set the recording level independently on the left and right sides. After adjusting the level of the left and right sides, you can adjust the recording level in conjunction with the master volume.

Equipped with New DPSS (Direct Program Search System) with fast response speed.
With this function, you can perform various functions such as music selection functions such as starting one song before or after or starting the desired song, repeated performance functions such as one song repeat / one side repeat, Re-rec standby which rewind to the beginning of the song when you want to rerecord it after starting recording, rewinding play which starts from the beginning of the tape when it ends halfway, 0 stop which automatically rewind to the position where the counter is reset, index scan, blank search, auto-rec mute, etc.

The 4-digit linear counter is a multi-function display which can be switched as a DPSS indicator and a residual quantity indicator.

Equipped with a wide-range 16-point FL peak hold level meter that displays from -36dB to + 12 dB.

Equipped with a linear tape counter that shows the tape running fee and remaining tape amount.
It is a high-precision 4-digit digital tape counter that detects time with a microcomputer. It also functions as a residual quantity meter with a blank search function, and it also functions as a track number display during DPSS operation.

It is equipped with FL display.

The capacity of the electrolytic capacitor in the power supply has been doubled compared with the conventional model.

Equipped with an auto tape selector.

Equipped with MPX filter.

Equipped with a headphone level volume.

Model Rating

Type	Stereo cassette deck
Track format	Stereo
Recording system	AC Bias (105 kHz)
Heads	Recording and Playback : amorphous alloy head Erasing : double-gap ferrite heads
Motor	Capstan Drive : FG Servo DD Motor Reel drive : DC motor Mechanical drive : 2 DC motors
Wow and flutter	± 0.054% (EIAJ) 0.027%(WRMS)
Early winding time	Approximately 70 Seconds (C-60 Tape)
Frequency characteristic	Normal tape : 20 Hz ~ 18 kHz ± 3 dB Chrome Tape : 20 Hz ~ 19 kHz ± 3 dB Metal Tape : 20 Hz ~ 22 kHz ± 3 dB
Distortion factor	Metal Tape : 0.8% (1 kHz, 3rd harmonic distortion rate)
Signal-to-noise ratio	EIAJ Metal Tape : 57 dB Dolby C on:74dB Dolby B on:67dB Dolby NR off:59dB
Input terminal	Line : 77.5mV/50k Ω
Output terminal	Line : 490mv/3k Ω Headphone : 0.85mW/8 Ω
Pwer	100 VAC, 50Hz/60Hz
Power consumption	24W (Electrical Appliance and Material Control Law)
External dimensions	Width 440x Height 115.5x Depth 322 mm
Weight	5.9kg