TEAC R-646X

Commentary

Auto-reverse deck with rotary head system.

The head section uses a rotating head system with A.R.H.S. (Acculine Rotating Head System).
Since the rotary head system uses the same head in both FWD and REV directions, it has the advantage that the electrical characteristics can be precisely matched. However, since the head is mechanically rotated, high quality in both directions requires high precision and durability of the rotating mechanism.
The newly developed A. R. H. S. is a system developed to cope with this situation. The head holder and bearing of the rotating part are made of high-precision die-casting with excellent shock absorbing power, which is lightweight, and is molded to the accuracy of micron order. This realizes smooth rotating operation and quiet rotating sound, as well as less shock and no distortion of azimuth.

The mechanism realizes stable tape running characteristics by dispersing the frequencies of the wow flutter by changing the diameter of the flywheels.

The tape end sensor of the reversal mechanism uses a reflective I. R. (infrared ray) sensor and realizes click reverse by increasing the reversal speed.
In this sensor, the semitransparent tape at the end of the tape is optically detected quickly, and instantaneous inversion operation is realized with almost no sound interruption.

The head is equipped with a CA (cobalt amorphous) head using an LC-OFC winding with excellent transmission characteristics.
By utilizing the thin foil characteristic of amorphous alloy with no crystal structure, we have achieved a 13-layer laminate structure that is approximately four times as large as that of conventional Sendust heads. The ribbon-shaped amorphous alloy greatly reduces eddy current loss, improves MOL with excellent magnetic properties, achieves flat high-frequency characteristics, and achieves high wear resistance without grain boundary peeling.

In the electric circuit, most of the amplifier system is integrated into an IC and integrated on a single board. The boards of the display and switches are also directly connected to prevent noise and reduce the length of wires.
In addition, careful management eliminates variations in parts, and the use of carefully selected parts, such as aluminum electrolytic capacitors for audio and high-performance film capacitors with high-sound quality design, reduces signal degradation.
The REC, PB, and NR sections are each made into blocks, and the power supply for the amplifier system and the power supply for the mechanism system are completely separated, and the winding of the transformer is completely separated, so that deterioration of sound quality due to mutual noise interference is suppressed.

A dbx system is installed as a noise reduction system.
In order to achieve higher precision in the R-646X, the dbx NR has been integrated into an L/R symmetric one chip LSI to eliminate variations in parts and improve operational stability.
High-precision encoding achieves an NR effect of 30 dB to 40 dB in the entire audible band.

Equipped with the Dolby HX Pro recording system, which greatly improves high-frequency recording capability.
The Dolby HX Pro automatically controls the bias amount according to the high-frequency component of the input signal to suppress tape saturation in high-frequency high-level recording high-frequency range. This enables recording of the same grade as high-performance recording on ordinary tapes.
Also, tapes recorded with this system can be played on devices that do not have Dolby HX Pro.

Specially programmed LSI is mounted for the mechanism control.
As the system control, it judges various input states, determines the operation mode and transmits it to the mechanism control, and controls counter display, memory operation and CPS.
The mechanism control controls the CAM motor to the specified position, controls the reel motor, controls the amplifier control output, and accurately displays the operation mode.

Dolby B/C NR is also installed as a noise reduction system.

Equipped with an MPX filter switch.

Equipped with Auto-Rec Mute which can create a silent part of about 4 seconds.

Equipped with a bias fine function that allows fine adjustment within ± 20% according to the characteristics of the tape.

Equipped with a CD level check function that can quickly determine the recording level of CDs.

It is equipped with functions such as the CPS system, which is a jump selection mechanism of 15 songs in front and back, a 15 song random program, and an intro check which continuously plays the head of a song for 15 seconds.

Equipped with 2 mode electronic counter of tape counter and tape run.

It is equipped with a block repeat function playback between any two points.

It is equipped with a blank scan function that automatically fast-forwards and plays when there is a silent part of more than 10 seconds.

Equipped with an FL multi-function display that displays information such as reverse operation.

Equipped with a large insulator with high damping effect.

Wireless remote control is included.

Model Rating

Type	Cassette deck
Track format	4-track 2-channel stereo system
Heads	1 Recording / Playback (LC-OFC / CA) Erase x1 * A. R. H. S. method
Motor	For Capstan : DC Servo Motor For Reel : DC Motor
Wow and flutter	0.05%(WRMS) ± 0.1% (Wpeak, EIAJ)
Frequency response (overall)	Metal : 20 Hz to 19 kHz Chrome : 20 Hz to 18 kHz Normal : 20 Hz to 17 kHz
Signal-to-noise ratio	59 dB (NR off, 3% THD level, WTD) 69 dB (Dolby B NRon, 5 kHz or higher) 74 dB (Dolby C NRon, 1 kHz or higher) 90 dB (dbx NRon, 1 kHz)
Dynamic range	110 dB (dbx NRon, 1 kHz)
Early winding time	Approximately 100 Seconds (C-60 Tape)
Input	Line : 87mV/50k Ω or more
Output	Line : 0.43V/50k Ω or more Headphone : 8 Ω
Pwer	100 VAC, 50Hz/60Hz
Power consumption	17W
External dimensions	Width 435x Height 109x Depth 295 mm
Weight	5.0kg
Attachment	Wireless Remote Control