DENON DP-51F

Commentary

Full auto player with almost the same configuration as DP-52F and MM type cartridge installed

Adopts a full auto mechanism.
The tone arm is driven by a non-contact structure that does not affect the tone arm sensitivity or rotation system, and smooth operation is achieved by microprocessor commands.
In addition, it is designed for safety. When there is no record on the turntable, the tone arm does not operate, so there is no trouble of needle tip.
In addition, by the adoption of electronic servo lifter, it is not affected by temperature and needle pressure, etc., and the tone arm shows up and down movement at a constant speed, and the impact between the needle tip and the record is minimized.

With the full auto function, when you press the Start button, the sensor automatically detects the size and rotation speed of the record (33 1/3 rotation for 30 cm, 45 rotation for 17 cm) and the performance starts. In the case of a record such as a 45 rotation disc for 30 cm records, you can respond by pressing the Start button and then pressing the specified rotation speed button.

The tone arm is equipped with a dynamic servo tracer light mass straight arm.
As a straight arm with a light mass, the fo is set at around 10 Hz to avoid the influence of the modulation noise in the ultra-low band caused by the warping of records, etc., and further to be out of the audible band.
In addition, the dynamic servo tracer controls the Q to an ideal state. This is a method of controlling the current flowing in the drive coil by detecting the minute movement (horizontal and vertical) of the tone arm with the detection coil. This suppresses the force of the arm moving in the direction opposite to the needle vibration at the fo point, greatly improving the tracing capability.

The appropriate needle pressure is obtained by operating the vertical axis drive coil of the dynamic servo tracer mechanism.

Equipped with an electronic anti-skating mechanism, it has a non-contact structure that cancels the inside force by controlling the current flowing in the arm's horizontal drive coil, so you can always get an appropriate amount of cancellation without sensitivity loss due to mechanical friction.

The motor is equipped with an AC servo motor, which is characterized by low electrical noise and no cocking.

It uses a DENON quartz speed servo mechanism that combines a high-accuracy magnetic recording detection system with a quartz lock.
The magnetic recording detection method employs a speed detection method at approximately the outer circumference of the turntable, which is best detected by a wow / flutter. The magnetic head detects 1000 pulse signals recorded magnetically at an accurate pitch inside the rim of the outer circumference of the turntable. This detection method detects 555.5 Hz at 33 1/3 rotation, which is higher than that of the general FG method. Therefore, it realizes a stable servo system with excellent detection accuracy and response and high gain.
The magnetic recording head uses a 2-in-1 type servo mechanism that is effective in both directions. This servo mechanism not only servos the rotational speed lag, but also provides quick response at the start-up time. It is also effective at the start-up and drop-down times when the rotational speed is changed.

An electronic brake is adopted, and the brake operation starts immediately after the needle tip is separated from the record surface after the record performance is finished, and the brake operation is released after the turntable stops, realizing a mechanism without reverse rotation.

The cabinet uses a slim design wood cabinet with a wood-grain finish.
Self-illuminated feather touch switches are used.

It uses a quick repeat method so that the tone arm does not return to the arm rest during repeated performance, but returns directly to the starting point of the performance of the record.

The cartridge is equipped with MM type cartridge DL-60 as standard.
The elliptical needle reduces tracing distortion in the high frequency range.

It adopts a special head shell replacement system and comes with a carbon head shell that is lightweight and has high resonance resistance.

In order to improve adhesion to the phonograph record and vibration damping effect, we have adopted a turntable sheet that has been thoroughly analyzed in terms of both material and shape.

It uses an insulator with high vibration isolation effect and adjustable height.

Uses a low-capacity output cord.

An integrally molded dust cover has been adopted.

Model Rating

Type	Full auto player
Phono Motor Section
Drive system	Bidirectional servo direct drive
Motor	AC servo motor
Speed control system	Speed servo and phase servo by frequency detection
Number of revolutions	33 1/3, 45 rpm
Wow and flutter	0.01% w. rms (rotating system) 0.02%w.rms(JIS)
Rotational speed deviation	0.002% or less
Speed switching mechanism	Soft touch push button
Signal-to-noise ratio	78 dB or more (DIN-B)
Startup time	Within 1.8 Seconds (33 1/3)
Load characteristic	0% (Needle Pressure 80g Outer Circumference)
Brake	Electronic brake
Power supply voltage characteristics	0% for 90 to 110 v variation
Turntable	Aluminum Die Cast 30 cm
Moment of inertia	200 kg / cm2(including turntable and seat)
Tone Arm Section
Type	Dynamic Balance, Special Shell Replaceable Light Mass Straight Type Electronic damping servo full auto arm
Effective length	244mm
Overhang	14mm
Tracking error	2.5 degrees or less
Needle pressure variable range	0 ~ 3g
Applicable Cartridge Dead Weight	Approximately 3 ~ 12g
Head shell	Special Hard Resin Dedicated Type PCL-50 : Approx. 3.3g
Output code	Low Capacity Cord Approx. 1.2m
Attachment mechanism	Electronic anti-skating mechanism electronic servo lifter
Cartridge Section
Type	MM Type (DL-60)
Output voltage	2.5mV
Playback frequency range	20 Hz to 30 kHz
Compliance	10x10-6cm/dyne
Needle tip	0. 3x0. 7 mil
Applicable Needle Pressure	1.8 ± 0.36g
Exchange needle	DSN-60(¥5,000)
<General>
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	14W
External dimensions	Width 455x Height 130x Depth 424 mm
Weight	Approximately 9 kg