KENWOOD L-D1

Commentary

The L series CD player was developed with the aim of the new 90's standard machine.
It is designed with high sound quality, such as the pursuit of stable operation during CD playback, review of all internal signal paths, and emphasis on high margin in all parts of the structure and circuit.

In order to reduce fluttering caused by warpage and deflection of lightweight CD disks, we have adopted a top-loading system in which a turning table is fixed directly to a spindle motor.
In this system, the recording surface is set upward, and the disk is pressed on a smooth φ 130 mm aluminum turntable with a clamper weighing approximately 100g. The moment of inertia is approximately 20 times larger than that of the conventional system, thereby achieving excellent stable operation and improved rigidity.
As a result, the servo amount is minimized, power supply fluctuations due to changes in the servo amount are reduced, and high-purity RF signals are successfully generated.

The pick-up section is designed with a bridge-like structure that spans a disk on a φ 5 mm guide that is robust and very vibration-free.
The bridge structure pickup section made of heavy aluminum die cast drives a coreless motor without cogging with a belt, so it moves extremely smoothly on the guide and enables more accurate reading of pits.

The pickup actuator drive uses a discrete high-performance audio amplifier instead of the conventional operational amplifier IC to enable accurate reading of signals on the disk and clean operation without contaminating the power line and ground line.

The spindle motor that drives the turntable uses the same 3-phase, 8-pole, 12-slot outer rotor brushless spindle motor as high-end LD players.
This motor is a high-torque, low-cogging, powerful motor with a φ 6 mm shaft developed for LD. It has a high ability to rotate an LD disk with 20 times the mass of a CD disk at about 4 to 5 times the rotational speed of a CD. It has a diameter three times that of a conventional spindle motor, so servo response and shaft torsion are greatly improved compared to conventional spindle motors for CDs.

Super C developed with the L-A1 integrated amplifier of the L series⁴(Super Constant Current Cascode Circuit) is used for the audio stage.
Audio stage amplification, which used to be composed of operational amplifier ICs, is composed of a full-scale amplifier of discrete design with an emphasis on performance.

Printed circuit boards are made of high-strength glass epoxy boards, which are used as commercial circuit board materials.
In addition, the board is mounted on a rigid 2 mm thick frame via steel studs to improve reliability.

The D/A converter section uses a PDM conversion bit stream 1-bit D/A converter. In addition, an independent switched capacitor on the left and right sides is also installed to reproduce the sound field more finely.
The digital filter is an 8 x oversampling type.

The analog output terminal realizes an ultra-low impedance output of 0.1 Ω, and suppresses external noise signals superimposed on audio cables more than ever before.

In order to prevent interference between the digital and analog systems, separate transformers are installed.
In addition, the microcomputer and display tube are supplied with power from a dedicated transformer, creating an ideal power supply for each system.

To clarify the moving and reference points, the drive mechanism for the large turntable is mounted on a 4-mm-thick aluminum die-cast chassis and is firmly supported by an 8-mm-thick aluminum extruding mechanism frame fixed in a rigid frame.
The front panel is made of 5 mm thick aluminum extruding material. The mechanism, digital control, digital / analog power supply, and power supply / analog demodulation sections are separated by 2 mm thick steel plates on the body frame and bottom plate to prevent interference between each part and improve the rigidity of the housing.
In addition, the top plate is made of 3.8 mm thick aluminum extruding material to divide the air chamber at the front part of the body and the air chamber at the rear part to reduce interference caused by radiation and vibration.

Panels and keys are made of cutting material or extruded material with sufficient thickness to improve rigidity and reliability.
In addition, the pin jack adopts a high-reliability type with gold-plated brass.

In order to prevent accidents such as damage caused by incomplete loading of the CD, a clamper detection mechanism is installed that does not start playback unless a clamper is set.

3-step door position (opening / closing angle) of 45 ° / 60 ° / 80 ° can be selected for cases where upper space is restricted such as installation on a rack.

It has an optical and coaxial digital output with an on/off switch.

Equipped with A/B automatic EDIT function considering tape copy.

Wireless remote control is included.

Model Rating

Type	CD Player
Number of revolutions	200 rpm ~ 500 rpm
Frequency characteristic	4 Hz to 20 kHz
Signal-to-noise ratio (EIAJ)	108 dB or more
Dynamic Range (EIAJ)	100 dB or more
Total Harmonic Distortion Factor (1 kHz, EIAJ)	Not more than 0.001%
Channel Separation (EIAJ)	100 dB or more
Output Level / Impedance	Variable Output 1, 2 : 2.5V/0.1 Ω Digital Output (Coaxial) : 0.5Vp-p/75 Ω Digital output (optical) : -15dBm to -21dBm at 660 nm
Power supply voltage	100 VAC, 50Hz/60Hz
Rated power consumption (Electrical Appliance and Material Control Law)	25W
Maximum external dimensions	Width 476x Height 128x Depth 430 mm
Weight	20.0kg
Attachment	Wireless Remote Control