YAMAHA P-550
¥ 39,800 (around 1981)
Commentary
A record player with some functions of the P-650 changed or omitted.
The difference from P-650 is that the servo system for controlling the number of revolutions of the motor is an FG servo circuit with pitch control, and the arm height cannot be adjusted.
The tone arm uses an ARS (Anti Resonance Straight) arm developed by Yamaha to reduce any resonance of the arm itself.
The ARS arm has a symmetrical structure with a straight pipe so that torsional vibration hardly occurs. In addition, a large rectangular balance weight placed as close as possible to the fulcrum, a span between pivots that is more than twice the normal size, and a rubber damper for the angular contact bearing of the bearing are used to improve sensitivity and eliminate resonance due to backlash. In addition, the pipe holder is large and robust, and a double structure 30 mm from the fulcrum is used to deal with flexural vibration at the front and back of the pipe.
The low-pass resonance frequency of the arm was determined to be 12 Hz from the result of measuring the reproduction spectrum of the direct cut record, and the effective mass of the arm was determined by calculating the average mass and compliance of 30 typical MM/MC type cartridge models.
The head shell part uses an insertion type that is highly reliable and easy to replace the cartridge. In addition, the needle pressure adjustment is a sliding weight type.
The cartridge uses CG-6700, a VM type cartridge.
A DC4-phase 8-pole coreless Hall motor is used as the drive motor.
This motor has no cogging in principle, and is a non-contact type using a Hall element, so mechanical and electrical noise is minimized.
FG servo is used in the servo circuit.
In this circuit, the signal detected by the frequency generator directly connected to the motor is compared with the reference voltage and fed back to the drive circuit of the motor, so that it can respond quickly to load fluctuations.
In addition, an all-round integration type, which is less affected by FG errors, has been adopted to improve accuracy.
Uses front operation with a switch so that it can be operated even with the dust cover closed.
In addition, auto lead-in, Oatley turn, auto cut and auto repeat are possible with full auto mechanism.
Using the pitch control knob on the front of the player, you can continuously adjust the rotational speed of the turntable by ± 3% by changing the reference voltage this is an application of the fact that the turntable is driven by an FG servo motor.
In order to adjust the rotation speed to the correct rotation speed, it can be set while checking by the mirror type strobe embedded in the deck panel. This strobe has four patterns of 50 hz : 33 1/3rpm and 45 rpm, 60 hz : 33 1/3rpm and 45 rpm.
The cabinet is made of BMC material and uses a 3-mm-thick acrylic resin dust cover and a special rubber W-shaped fold-back insulator to improve the howling margin.
.JPG)
Model Rating
| Type | Record player |
| Phono Motor Section | |
| Drive system | Direct drive |
| Servo system | FG Servo |
| Motor | DC4-phase 8-pole coreless Hall motor |
| Number of revolutions | 2 Speeds (33 1/3rpm, 45 rpm) |
| Turntable | 30 cm Aluminum Die Cast, 1.6 kg (Including Rubber Sheet) |
| Moment of inertia | 210 kg / cm2(Including Rubber Sheet) |
| Tone Arm Section | |
| Type | Straight arm |
| Total Length | 290mm |
| Effective length | 222mm |
| Overhang | 16mm |
| Horizontal tracking error angle | -1 ° ~ 3 ° |
| Needle pressure application system | Sliding Weight Method (0 ~ 3g, 0.1g step) |
| Effective mass | 11g (when needle pressure is 1.5g, cartridge weight is not included) |
| Compatible Cartridge | 2.5g ~ 10g |
| Arm initial motion sensitivity | Vertical : 10 mg Horizontal : 30 mg |
| Arm lifter | Oil dump type queuing |
| Anti-skating | Spring lever type |
| Head shell | Insertion Type, Dead Weight 2.5g |
| PU cable | Capacity : 100 pf Reciprocating resistance : 1 Ω |
| Cartridge Section | |
| Type | VM Type (CG-6700) |
| Output voltage | 2.5 mv (1 khz, 5cm/sec, Peak45 °) |
| Channel separation | 18 dB or More (1 kHz) |
| Electrical impedance | 2.8k Ω ± 30% (1 kHz) |
| Proper needle pressure | 2.0g ± 0.5g |
| Dynamic Compliance | 12x10-6cm/dyne(100Hz) |
| Weight | 6g |
| Automatic Control Section | |
| Auto function | Auto Lead In (17 cm, 30 cm) Auto return Repeat Cut |
| Body Part | |
| Cabinet | BMC(Bulk Molding Compound) |
| Finish | Silver |
| Dust cover | 800g acrylic resin |
| HINGE | Fleece Top Removable |
| Insulator | W-shaped Folded Rubber |
| <General> | |
| Signal-to-noise ratio | 77 db (DIN-B, IEC 98A weighted) |
| Wow flutter | 0.015% (FG Direct) |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 7W |
| External dimensions | Width 440x Height 132x Depth 372 mm |
| Weight | 6.8kg |