Audio Database

TX-DS777
Commentary

This AV amplifier is compatible with Dolby Digital and DTS, and is also certified by THX SELECT.

Among the Home THX Cinema standards by Lucasfilm, it is certified by THX SELECT, a standard intended for use in a relatively small room of approximately 57 cubic meters. This standard is certified only for products that have passed a wide range of rigorous screening including product design concepts, THX technology realization devices, product features and ergonomics, technical composition, and audition screening.

The Dolby Digital and DTS signals are decoded using 24 bitDSP of Crystal Semiconductor Products Division developed exclusively for audio. The DSP has twice the processing power of the general 24 bitDSP by improving the signal processing method.

The A/D converter is equipped with 96kHz/24bit IC, and the D/A converter is equipped with 96kHz/24bit IC.

DAC circuit configuration with non-scaling configuration is adopted.
Normally, when downmixing, such as when the center channel is not played, the center channel signal and the front channel signal are added in the DSP before being processed by the D/A converter. In this case, the maximum value (full scale) that can be handled in the DSP is overflowed, so the dynamic range is degraded because the addition is performed after scaling (half the amount of data for the front and center channels).
In addition to the 6-channel DAC (total of three chips), the TX-DS777 has another 2-channel DAC chip, enabling full-scale transmission without adding two types of signals in the DSP.

WRAT (Wide Range Amplifier Technology) has been introduced to extend the frequency characteristics of a bare circuit without negative feedback to high frequencies and to reduce the distortion factor. By this, the frequency band can be extended to 100 kHz by applying only a small feedback that does not affect the audibility.

By stabilizing the ground potential, which is the reference for the audio signal processed in the amplifier, more accurate audio signal propagation is possible.
In the TX-DS777, we focused on the fact that the audio signal passing through the amplifier itself changes the ground potential, and succeeded in stabilizing the ground potential by closing all the networks into a loop.

High Instantaneous Current Capability (HICC), which can instantaneously supply a large current, has been introduced in order to accurately drive speakers under various conditions caused by rapidly changing audio signals.

It is equipped with an on-screen display function that displays the menu screen on the TV and makes various settings.

Equipped with 5.1 ch pre-out output capable of connecting 5.1 ch input terminal and external power amplifier.

Surround modes include Action, Unplugged, Musical, Studio-Mix, Mono Movie, 5 ch Stereo, Orchestra, and TV Logic.

The remote controller comes with a learning function to learn how to operate peripheral devices such as a TV or DVD player, and a macro function to memorize continuous remote control operations.

Model Rating
Type AV amplifier
Amplifier Unit
Rated output
(6 Ω, 1 kHz, THD0.1%)
Front : 135W + 135W
Center : 135W
Surround : 135W + 135W
Maximum Practical Output (6 Ω, EIAJ) Front : 170W + 170W
Center : 170W
Surround : 170W + 170W
Total harmonic distortion factor 0.08% (at rated output)
Cross modulation distortion factor 0.08% (at rated output)
Dynamic Power 180W + 180W (front, 4 ohm)
Damping factor 60 (Front, 8 Ω)
Input Sensitivity / Impedance Line : 200mV/50k Ω
Phono MM : 2.5mV/50k Ω
Multi-channel input : 200mV/50k Ω (excluding Subwoofer)
Subwoofer input : 36mV/50k Ω
Output Level / Impedance Rec out Tape/Video1 : 200mV/2.2k Ω
All channels except Pre out : 1V/470 Ω
Frequency characteristic Line input : 20 Hz to 100 kHz + 1-3 dB (in stereo)
Signal-to-noise ratio (IHF-A) Line:100dB
Phono:80dB
Tone Control Maximum Change Bass : ± 10 dB (50 Hz)
Treble : ± 10 dB (10 kHz)
Phono RIAA deviation 20 Hz to 20 kHz ± 0.8 dB
<Video Part>
I/O Level / Impedance Composite Signal : 1Vp-p/75 Ω
Y Signal : 1Vp-p/75 Ω
C Signal : 0.28Vp-p/75 Ω
Tuner Section
Practical sensitivity of FM Mono : 1.0 μ V/11.2 dBf
Stereo : 2.0 μ V/17.2 dBf
Signal-to-noise ratio FM mono:76dB
FM stereo:70dB
Harmonic distortion factor FM mono:0.2%
FM stereo:0.3%
<General>
Image input S connector : Line 5 (DVDs, Video1-4)
Composite connectors : Line 5 (DVDs, Video1-4)
Video output S connector : Route 3 (Video1, 2, Monitor out)
Composite connector : Route 3 (Video1, 2, Monitor out)
Voice input Digital terminal : 4 systems (2 optical, 2 coaxial)
Analog connector : 8 systems (DVD, Video1-4, Phono, CD, Tape)
5.1 ch analog terminal : 1 system
Audio output Digital terminal : 1 system (optical)
Analog jacks : Route 3 (Video1, 2, Tape)
Pre-output jacks : Front L/R, Center, Surround L/R, Subwoofer
Speaker output : front L/R2, center, surround L/R
Headphone output : 1 system
Power consumption 420W (Electrical Appliance and Material Control Law)
External dimensions Width 435x Height 175x Depth 453 mm
Weight 16.3kg
Attachment Wireless Remote Control