DENON DP-3700F

Commentary

A record player corresponding to the upgraded model of DP 3700.

The DP 3700 f has improved its vibration isolation performance by improving the cabinet and arm base.

DP-3000 is adopted for the turntable part.
The DP-3000 uses a direct drive system for its drive system, and DENON's unique high-precision magnetic recording and playback system for rotational speed detection.
In the magnetic recording / reproducing system, the voltage applied to the motor is controlled by comparing the voltage obtained from the actual rotation of the turntable with a reference voltage. The voltage from the turntable is obtained by detecting pulses magnetically recorded with high precision on the inner circumference of the turntable with a magnetic head and converting them into voltages corresponding to their frequencies. There are 1000 pulses, and the pulse interval is recorded with an accuracy of 1/10000. This pulse enables extremely accurate speed detection and extremely fast and sufficient servocontrol. Wow flutter is suppressed to 0.03% or less. In addition, stable rotation is maintained even when load conditions such as needle pressure change.

The servo circuit is fully temperature compensated and has a built-in DC stabilizing power supply to prevent the rotational speed from being affected by fluctuations in the power supply frequency, voltage, and temperature.

Solid rotor type AC servo motor is used as the drive motor.
Compared to other synchronous motors and DC motors, this motor has smooth rotation characteristics with less vibration. However, it is driven by AC with a beautifully shaped waveform, so there is almost no rumble.

By adopting an accurate and quick response speed detection system and a stable servo system, the weight of the turntable has been reduced. As a result, the starting characteristic is less than 1/2 revolution, and the bearing load of the motor is light, so that stable performance can be maintained over a long period of time.

Speed switching by electric switch is adopted.

Fine adjustment of speed is possible, and adjustment of ± 3% of the specified speed is possible.

The tone arm uses DA 305, a model conforming to the broadcast station specifications.
Designed for safe use with light needle pressure cartridges, the DA 305 is a laterally balanced S-shape. The needle pressure adjustment is a micrometer type direct reading type with 0 to 1g per rotation, and the cartridge can be used over a wide range of weight from 4g to 15g.

In order to maintain high sensitivity and high reliability, the rotary bearing section has the same consideration as the arm for broadcasting station.
The horizontal rotation axis consists of two high-grade miniature bearings protected by a double housing. The vertical rotation part consists of an angular contact bearing protected by a special elastic material with little friction change combined with a quenched and precision polished pivot, making it stable against external vibration and impact while minimizing resonance of the arm itself.

It uses a special low-capacity output cord and is compatible with MM type cartridges with high output impedance and 4-channel record playback.
In addition, the connector is gold-plated to eliminate troubles caused by poor contact.

The cabinet is made of laminated plywood with a thickness of 70 mm to increase the mass and suppress resonance of the cabinet itself.
In addition, a mechanical filter of viscoelastic material is used between the arm base and the cabinet to absorb the vibration of the cabinet transmitted to the tone arm.

A height adjustable insulator is used for the leg part to absorb vibration from the floor.

Model Rating

Type	Player system
Phono Motor (DP-3000)
Drive system	Direct drive
Motor	Solid rotor type AC torque motor
Speed control system	Servo system by frequency detection
Number of revolutions	33 1/3rpm, 45 rpm
Speed switching mechanism	Electrical switching
Rotational speed adjustment range	+ / - 3% (for specified speed)
Wow and flutter	0.03% wrms or less (according to test records)
Signal-to-noise ratio	60 dB or more
Start-up characteristic	1/2 Rotation (1.8 Seconds) or Less (at 33 1/3rpm)
Turntable	30 cm Aluminum Die Cast, Dead Weight 1.1 kg
Moment of inertia	160 kg / cm2
Tone Arm Section (Excluding DA 305 and Arm Base)
Format	Static balance type
Effective length	244mm
Overhang	14mm
Offset Angle	20.5 ゜
Tracking error	Within ± 2 °
Needle pressure adjustment range	0 ~ 3g (0.2g per scale)
Applicable Cartridge Dead Weight Range	4g ~ 15g
Head shell dead weight	8.5g
Arm Height Adjustment Range	40 ~ 55 mm
Head connector	EIA standard 4P connector
Arm lifter	Oil dump type
Arm base	With Mechanical Filter
<General>
Cabinet	70 mm Plywood
100 VAC, 50Hz/60Hz
External dimensions	Width 530x Height 180x Depth 440 mm
Weight	15kg