SANSUI SR-525

Commentary

A direct drive player developed based on SR 717 technology.

The drive unit uses a direct drive system, and the drive motor uses a high-torque 20-pole 30-slot multi-slot multi-groove DC servo motor with a newly developed bias-system saturable magnetic core type position detection mechanism built in and a high-torque 20-pole 30-slot multi-pole multi-groove structure.
The servo motor with this bias-type saturable core type position detection mechanism directly detects the position of the rotor magnet and controls the current flowing in the switching circuit for driving the motor. In addition, a three phase AC voltage proportional to the rotational speed is generated in the power generation coil by the bifilar winding together with this coil, and the switching circuit for driving the motor is controlled by the potential difference compared with the reference voltage to obtain high-precision rotational speed.

By improving the accuracy of the compensation circuit in the switching mechanism of the motor, and by designing the shaft and bearing with mirror finishing and special heat treatment, excellent audio characteristics have been obtained.

The tone arm uses a static balance type S-magnetic pipe arm. Zinc alloy die-cast is used for the hold part and base part that hold this arm. This not only increases strength but also prevents the generation of harmful partial resonance that affects the sound quality.
In addition, a double-structured special washer is used to strengthen the rigidity of the mounting part of the arm body, and a special dump material is inserted into the cavity inside the pipe arm to eliminate resonance of the pipe part.
For the vertical support of the tone arm, a knife edge support system with good follow-up by special steel is adopted. This system has a simple structure, so it has high mechanical strength and maintains initial performance for a long period.
In addition, the horizontal direction adopts an assembly bearing using a precision finished steel ball, and it is designed to be highly sensitive as in the vertical direction.

The tone arm is equipped with a string-suspended inside four scan cellar, a lateral balancer, a direct-reading balance weight, an independently operated oil-dump-type arm lifter, and an arm height adjustment mechanism with a variable range of 5 mm.

The shell and arm connection terminals are gold-plated.

SV-42 MM type cartridge is used for shearing in the cartridge part.

The head shell -cast with excellent mechanical strength is used for the head shell.
In addition, the integrated structure of the arm finger prevents harmful partial resonance and modulation distortion.

The cabinet is made of a solid board developed for acoustic use, and the motor section is hollowed out. As a result, it is made of a material with large mass and high internal loss, with a large howling margin and clear sound quality.
For direct vibrations from the floor, we have adopted an insular system that takes into consideration the weight balance with the cabinet, and a thick rubber sheet is used to cope with howling.

Equipped with a speed fine adjustment mechanism of ± 3.5%.

A low-capacitance (40pF/m) output code with good high-frequency characteristics is used.
4-channel playback is also supported by changing the cartridge.

Equipped with a fleece top type dust cover.

Model Rating

Type	Record player
<Turntable portion>
Drive system	Electronically controlled direct drive housiki
Motor	20 Pole Brushless DC Servo Motor
Rated speed	33 1/3 and 4 rpm
Speed adjustment	± 3.5%
Turntable	310 mm Diameter Aluminum Alloy Die-cast
Wow and flutter	0.03% or less (WRMS)
Signal-to-noise ratio	60 dB or More (JIS)
Tone Arm Section
Type	Static balance S-shaped pipe arm Knife edge method, needle pressure direct reading method Inside for scan seller Lateral balancer 4 Extreme plug-in head type
Effective length	220mm
Overhang	17.5mm
Cartridge Section
Type	MM Type (SV-42)
Frequency characteristic	10 Hz to 22 kHz
Output voltage	3.5 mv (1 kHz, 50mm/sec)
Load impedance	50k Ω
Proper needle pressure	1.5 ~ 2.0g
Needle tip	0.5 mil Diamond Needle (SN-42)
<General>
Rated power consumption	5W
External dimensions	Width 469x Height 150x Depth 375 mm
Weight	9.4kg