DENON DP-5000

Commentary

A direct drive turntable that inherits the performance and design of the DP 5000 and pursues cost performance.

In the DP 5000, the pulse recorded inside the rim of the turntable is first detected by a magnetic head for speed detection. The pulse signal is amplified and passed through a limiter circuit. A demodulation circuit converts the change in speed into a change in voltage. This voltage is compared with a reference voltage set in advance to achieve the specified speed. The voltage difference is used to control the motor drive power supply voltage for servo control.
As a result, the speed can be easily changed by changing the reference voltage. The circuit and elements used are highly stable, and highly reliable characteristics can be obtained even with temperature change, aging change, negative variable and simultaneously.

In speed detection, the inside of the rim of the turntable is coated with a magnetic material with a large coercive force. Using a special method, pulses of a fixed wavelength are recorded with high precision and high density. This is detected by a magnetic head mounted at intervals of approximately 1/10mm.
In this method, the wavelength error of recorded pulses is suppressed to less than 0.01%, and the frequency of detected pulses is approximately 1100 Hz at 33 1/3rpm because pulses are recorded at 2000 locations around the turntable.
This frequency is more than 10 times higher than other methods, making it possible to greatly reduce the time constant of the integration circuit in the frequency-voltage conversion circuit.

The turntable has a weight of 1.1 kg and an inertial mass of 160 kg ・ cm.²Lightweight turntables have been adopted to speed up the start-up time, reduce the load on the bearing, and obtain long-term stable performance.

The speed fine adjustment selection button can adjust the speed by ± 6% under variable conditions.

The motor is a solid rotor type two phase torque motor with an extremely smooth rotating magnetic field, and a dedicated amplifier is used to drive the motor to reduce rumbling.

Model Rating

Type	Turntable
Drive system	Servo-operated direct drive
Motor	Solid rotor type 2-phase torque motor
Speed control	Servo by frequency detection
Number of revolutions	33 1/3, 45 rpm
Speed switching mechanism	Electrical switching
Startup time	1.2 seconds (1/3 rotation, 33 1/3rpm)
Wow and flutter	Less than or equal to 0.025% wrms (according to test records)
Motorboard	Aluminum die cast
Signal-to-noise ratio	60 dB or more
Turntable	30 cm aluminum die-cast, 1.1 kg
Moment of inertia	160 kg / cm2
Rotational speed adjustment range	Variable : + / - 6%
Pwer	100 VAC, 50Hz/60Hz
External dimensions	Width 370x Height 139x Depth 374 mm
Weight	6.8kg