YAMAHA GT-CD1

Commentary

This is a CD player which introduced the GT (Gigantic & Tremendous) idea adopted by record players such as GT-2000.

The GT-CD1 uses a highly rigid and non-resonant structure based on the GT concept.
The entire structure consists of a woodbase made of 60 mm thick high-density particleboards incorporating Yamaha's woodworking technology and a mechanical base made from gunmetal castings. The exterior is made of American Walnut with a beautiful sound and polyester mirror finish with a piano finish.
In addition, this wood base is lined with a 2.3 mm thick iron plate and connected directly to a 60 mm diameter pinpoint leg with four 22 mm hex iron pillars. The height of this leg can be adjusted by fixing it with screws. In addition, it comes with a leg base that can be detached with magnets.
Under the player part, the D/A converter unit is built into a frame structure chassis made of 8 mm thick aluminum block and connected to the wood base. Non-floating rigid structure is adopted for all parts.

The player and DAC parts are completely separated in a separate structure. Furthermore, the separated player and DAC parts are placed in one housing in an "integrated separate structure".
In addition, by placing the master clock in the DAC section and using a VCXO system for the clock in the player section, we have achieved the same level of jitter as an all-in-one player despite the separate structure.

The mechanism section uses a top-entry system with a disc player on the base of a 3 kg housing made by cutting out the entire cast gunmetal.
The spindle motor uses a high torque brushless motor with a shaft diameter of 4 mm, with an iron plate attached to the bottom to increase quietness. In addition, the disc table is burn-polished with rubber after cutting out brass to ensure high accuracy and prevent slipping during acceleration and deceleration.
The clamping system of the disc is a full gravity system and uses a 160g self-weight brass shaving stabilizer clamper. The direct guide ensures high accuracy, and the entire player part is tilted forward 2 degrees to prevent shaft oscillation and stabilize the oil film of the shaft receiver.
The top entry lid is made of polished 10 mm thick tempered glass, supported by an aluminum frame and driven by a computer-controlled motor.

The optical pickup uses a 3-beam system and is guided by two precision shafts.
For the feed mechanism, a timing belt system with a 5-slot motor and a speed reduction mechanism has been adopted instead of a linear motor in order to pursue smoothness during reproduction rather than high speed to improve stability and vibration control.

The D/A converter section is equipped with D/A systems such as Yamaha's original secondary noise shaping, I-PDM 1-bit DAC, and TBC with higher precision.
The main improvements are as follows : Review of noise shaping to improve the output level by 4 dB by making the most effective use of signal components. Adoption of newly developed LSI capable of 20-bit input. Detection of Infiniti 0 improves the output of the noise shaping circuit and eliminates fluctuation components. Optimization of FET size of output inverter to optimize the waveform of output pulse and reduce unnecessary radiation due to high frequency noise.
In addition, the twin DAC system, in which the DAC with the processing capacity for two channels in one chip is used independently on the left and right sides, prevents mutual interference. In addition, the signal of one channel is output in two systems with positive phase for the signal component and negative phase for the dither component. By combining these outputs, the dither component is canceled and random noise is reduced by 3 dB.

The DAC section is located on the same main board as the audio amplifier section, but it is shielded by a copper plate to prevent interference with the audio amplifier section. A shield plate is also placed between each DAC to eliminate mutual interference between channels.

The use of second order noise shaping and twin DAC system greatly reduces noise outside the audible band. Therefore, the third order active type low-pass filter, which is advantageous in sound quality, is used.
The audio amplifier consists entirely of discrete transistors, with differential-input / complimentary service outputs and class-A operation at all stages to achieve pure amplification and transmission. In addition, only audio parts that have been examined through repeated comparative listening are used.
In addition, the twin DAC configuration completely separates the positive-phase and negative-phase signals from the DAC and realizes a balanced output capable of high-quality sound transmission by realizing a symmetrical balanced circuit containing four amplifiers with two channels.

The power supply section is separated from the servo / DAC system, audio amplifier system, and transformer, and is further divided into two transformers and three windings for the servo system and DAC system to eliminate mutual interference.
In addition, only the audio amplifier section is equipped with a powerful power supply section such as a 15Ax2 rectifier and a filter capacitor of 48000 μ F or more.

It uses a design that combines the player part with walnut polyester mirror coating finish and the DAC part with aluminum extruded material anodized finish.

3-step switching type is adopted for the display part.

Wireless remote control is included.

Model Rating

Type	CD Player
Frequency characteristic	2 Hz to 20 kHz ± 0.5 dB
Harmonic distortion factor	0.0015% or less (EIAJ)
Dynamic range	100 dB or more
Signal-to-noise ratio	120dB(EIAJ)
Channel separation	100dB
Wow and flutter	Below the measurement limit
Output	Analog : RCA pin unbalanced output Balanced output Digital : coaxial digital output
Pwer	100 VAC, 50/60Hz
Power consumption	30W
External dimensions	Width 435x Height 160x Depth 405 mm
Weight	24kg
Attachment	Wireless Remote Control