SONY DTC-690

Commentary

A DAT deck developed using the ES series technology.

Serial Copy Management System (SCMS) is adopted as copy protection.
SCMS is capable of digital → digital recording for only one generation using a CD as a master. Digital → digital recording for the second generation or later is not possible using a recorded tape. Similarly, digital → digital recording for one generation is possible using a source recorded with an analog input, but digital → digital recording for the second generation or later is not possible.
If only analog input / output is used, recording can be repeated without restriction of SCMS.

A 2D. D. + reel motor mechanism has been adopted in which independent direct drive motors are used for the capstan and head drum rotation respectively, and separate exclusive motors are provided for the reel.

A 1-bit A/D converter is used in the A/D conversion section. By performing high-magnification oversampling, unwanted sampling noise generated during A/D conversion is shifted to far higher frequencies outside the audible band. To prevent aliasing noise, the characteristics of the low-pass filter inserted before the A/D converter can be relaxed, enabling digital recording with good phase and group delay characteristics.

The D/A converter uses a pulse D/A converter that has a current source and an electronic switch, and performs D/A conversion based on oversampling and noise shaping operations. By switching the electronic switch on / off at high speed, sound is reproduced at the pulse density, and 0 cross distortion and differential nonlinear distortion are eliminated in principle.

We have adopted a software servo system that is a substantial software version of the microcomputer controlled motor servo system.
As a result, in order to avoid excessive load on the tape, a high-speed and smooth search operation is realized, with slow searching at the beginning and immediately before stopping, and up to 200 times speed (standard time) in the middle of driving.
In addition, software servo reduces the sound output time and improves the operability during cue / review operations.

It is equipped with the subcode function which is one of the features of DAT, and it is possible to set and erase start ID, skip ID and end ID.
The start ID is a subcode that indicates the beginning of a song. It is equipped with two modes : Auto, which is automatically written at the start of a song, and Manual, which can be written at any position you like (excluding immediately after the start ID, 9 seconds in SP mode, and 18 seconds in LP mode).
The skip ID is an ID that is written at the beginning of the part you want to hear when you play the tape. If you find the skip iD during playback, you can automatically forward it to the next start ID.
The End ID is a code that considers the part written to be the end of the tape, auto-rewinding for playback and stopping for fast forward.

It is equipped with a rehearsal function for writing start ID, skip ID / end ID, and point writing of A-B repeat, which are done in the playback manual.
During the rehearsal, you can move the point back and forth in 0.3 second increments while listening to and confirming the sound. The movement time is displayed on the display and can be easily written to the Just Point. You can also modify the Start ID that has already been written.

You can assign a program number to the Start ID, and you can directly select a song by simply specifying the number with the 10 key when you play it. The program number is automatically assigned when you record it or can be changed by changing the number.

By adding or deleting the start ID, if the program number is not uniform, a renumbering function is incorporated. This function renumbers the number from the beginning of the tape with one touch.

It is equipped with a shift number function that renumbers the start ID by adding it back in 0.3 second increments.

It is possible to record the absolute time which shows the absolute time from the tape top.

AMS play is possible in which you can start the previous or next song depending on the number of times you press AMS based on the song you are listening to.
In addition, by using the AMS button and the 10 key together, it is also equipped with AMS search which can find the beginning and end of the number of songs according to the number.

It is equipped with program number search, and by using 10 key and play button jointly, you can directly find the music which recorded the program number of the number you pressed.

Equipped with a music scan function, you can search for the start ID one after another and play it for about 8 seconds each.

Repeat playback of the specified program number and the entire tape is possible.

Equipped with end search, you can quickly find an end ID or an unrecorded part that has never been recorded.

By using the included remote control, you can play 99 RMS songs by rearranging the program numbers in the order you like.

Continuous recording for up to 4 hours (when using DT 120) is possible.

Two types of digital input terminals (optical and coaxial) are mounted, and an optical output terminal is mounted as a digital output terminal.
The optical input uses a servo-type digital signal normalizer circuit that absorbs jitter caused by cables.

It comes with a wireless remote control that can operate most of the body.

Model Rating

Type	DAT deck
Recording system	Rotary head system
Frequency characteristic	2 Hz to 22 kHz ± 0.5 dB
Total harmonic distortion factor	0.005% or less (EIAJ, Line Input)
Signal-to-noise ratio	90 dB or More (EIAJ, Line Input)
Dynamic range	90 dB or More (EIAJ, Line Input)
Wow and flutter	Below the limit of measurement (± 0.001% Wpeak) (EIAJ)
Input terminal	Line : 1 system Digital coaxial : 1 system Digital Light : 1 system
Output terminal	Line : 1 system Digital Light : 1 system Headphone : 1 system (stereo standard jack)
Pwer	100 VAC, 50Hz/60Hz
Power consumption	26W
External dimensions	Width 430x Height 110x Depth 350 mm
Weight	Approx. 5 kg
Attachment	Wireless Remote Control RM-D690