SONY TC-K777ES

Commentary

This is the highest model in the ES series that was developed with the highest priority on sound quality and without any compromise.

For the head part, the occupied space is equivalent to a combination head, and an independent suspension type 3-head system is adopted to obtain uniform head touch and high-precision azimuth for both recording and playback heads.
The head is equipped with a laser amorphous head that uses an amorphous magnetic alloy for the core material that has an excellent S / N ratio and is resistant to magnetic saturation.

The capstan drive employs a quartz-lock direct drive system in which the rotating shaft of the motor is used as the capstan as it is and the rotational speed is servoed with a quartz-lock.
The motor is a linear BSLD. D motor with high performance for audio equipment.

A closed-loop dual capstan system is adopted to obtain stable tape running and head touch.
The tape is held between two sets of capstan heads and pinch rollers to stabilize the tape running. The wow and flutter characteristics are improved by cutting off the tape vibration transmitted from the reel. Modulation noise can be excluded outside the audible band because the span of the tape vibration can be shortened. In addition, two tape tensions are utilized to realize constant head touch.
This improves the running stability of the tape and adhesion between the tape and the head.

The amplifier section has a L/R twin mono structure for all stages with a simple and straight concept, and a DC amplifier configuration with a circuit layout according to the signal flow.
In addition, the structure gives priority to sound quality by adopting a dual FET differential 2-stage SEPP circuit that eliminates direct coupling between the head and the reproducing amplifier and signal modulation factors as much as possible, and a high-efficiency deformed toroidal cutless core power transformer with separate layout.

In order to further improve sound quality, we have adopted a chassis structure that emphasizes sound quality.
For this reason, the base chassis uses copper-plated Copper-Tight, which prevents magnetic distortion of the audio circuits.
In addition, vibration to the tape running system is reduced by adopting a die-cast head base and buds or blocks to disperse vibration.

It is equipped with ± 20% bias calibration that can be finely adjusted for each tape used, and recording level calibration that maximizes the effect of Dolby NR.
In addition, the level meter display is switched according to the adjustment mode and becomes a dedicated display.

The IC that makes up the Dolby NR B/C circuit uses a symmetric process Dolby IC with symmetrical left and right channels for improved orientation.
Also, if you don't use Dolby NR, the NR circuit can be completely passed from the audio circuit.

Equipped with a multi-functional wide-range peak program meter and a linear electronic counter that digitally displays the amount of tape run in minutes and seconds.

Built-in functions such as counter-linked memory stop / play, Rec Mute with auto space, continuous recording / alarm clock playback with optional timer, and synchronized play with Sony player with RM-65.

It is equipped with a fixed output and a variable output. The variable output is a 5-step attenuator type with less impedance change and is linked to the headphone output.

Model Rating

Type	Stereo cassette deck
Heads	Playhead x1 1 Recording Head Erase Head x1
Motor	Two linear BSLD. D. motors
Signal-to-noise ratio	57dB(EIAJ) 61 db (Dolby off, Peak Level, Metal Tape) 74dB(Dolby NR C)
Frequency characteristic	15 Hz ~ 19 kHz ± 3 dB (EIAJ, metal tape)
Frequency range	10 Hz ~ 20 kHz (EIAJ, Metal Tape)
Wow and flutter (EIAJ)	± 0.036% Wpeak 0.020%WRMS
Distortion factor	0.3%(EIAJ)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	39W
External dimensions	Width 430x Height 105x Depth 390 mm
Weight	10.0kg