Denon AVC-A1SR specifications Thorough Vibration-resistant Design

■Thorough Vibration-resistant Design

Since the high-density data recorded on DVD must be read with absolute accuracy, vibrations from outside or from internal sources, such as the power supply, will adversely affect sound and picture quality. A variety of designs have been incorporated in the DVD-A1 to suppress these unwanted vibrations. The bottom plate forming the foundation of the chassis is a 6-mm thick, 4-layer hybrid construction made up of a 1.2-mm thick copper-plated metal sheet and three layers of 1.6-mm metal sheets. Large insulators of sintered alloy (the same type used in Denon's high-end S1 series) have been used for the DVD-A1's feet to absorb external vibrations. Reinforcing plates for the base, front, and rear are composed of four 1.2-mm thick copper- plated sheets, that have been utilized in a 3-box construction design to strengthen the chassis. The chassis also uses copper plating to bring the ground electric potential of the overall chassis close to equipotential in order to suppress electrical noise. The top cover uses three types of 1.2-mm thick metal sheets in different shapes, while 2.5-mm thick aluminum panels have been used for the sides, giving rigidity to the entire chassis. The DVD mechanism is mounted on a cast-aluminum base between the mechanism and the chassis. Parts made of different materials effectively absorb vibra- tions caused by the unit itself as well as from outside to ensure stable opera- tion.

■THX Ultra Certified

The THX Ultra certification standards are comprised of tests in three cat- egories; Audio Quality, Video Quality and User Interface. These tests ensure that a certified DVD player is fully capable of bringing out the best visual and sonic quality of all your DVD discs.

■Newly-Developed Loading Mechanism for Suppression of Vibrations

The newly-developed loading mechanism uses a guide and tray painted with protein material that is highly resistant to vibrations in order to prevent unwanted vibrations to the tray.

■New PureProgressiveTM Circuit

(NTSC Conversion Output Only)

The DVD-A1's interlace to progressive converter is the new SiI504 Converter with PureProgressiveTM circuitry from Silicon Image. The SiI504 features faster moving picture detection and improved film/video mode recognition capability.

High-speed processing: This Sil504 Progressive Converter is capable of processing 6 billion operations per second, providing the finest in motion- adaptive de-interlacing.

Moving picture detection: PureProgressiveTM features 2:3 pulldown detection, which converts 24-fps Film based material to 60-fps TV/Video playback, while also detecting Video based material, animation and graphics. PureProgressiveTM is capable of reproducing DVD-Video discs containing both Film and Video material, as well as high picture quality progressive video sources, while avoiding the flickering caused by detection delays of these different formats. In processing moving video signals, a conventional progressive converter performs detection on a full frame-by-frame basis, while PureProgressiveTM stores 4 fields of video signals in a 64-Mbit SDRAM buffer, enabling the detection and processing on a pixel-by-pixel basis to achieve greater precision in discriminating between moving and still pictures.

Improved 2:3 pulldown detection: There are cases in which 2:3 pulldown data signals on DVD-Video discs are not in sync. The PureProgressiveTM converter will quickly detect the non-sequential points and perform appropriate corrective measures at high speed to minimize picture flickering. It is now also possible to select Level Detection or Flag Detection as the detection method used for Film and Video material. If an incorrect flag was recorded or the difference between the video level and noise level is very small and distinctions on the disc are difficult to detect, this selection ensures optimum detection capability and minimizes picture quality degradation.

■14-bit, 108-MHz Video D/A Converter

The DVD-A1 uses a total of six 14-bit, 108-MHz video D/A converters to tap the maximum potential of the new PureProgressiveTM circuit's performance. The DVD-A1 uses independent D/A converters for Progressive and Interlaced picture reproduction.

These converters provide a very high sampling frequency of 108-MHz, with 4x oversampling used for Progressive and 8x oversampling for Interlaced operation, resulting in the highest detailed D/A conversion. Since a filter with ample cutoff characteristics can also be used for the analog low-pass filter, the DVD-A1 reproduces the delicate nuances of video signals, allowing viewers to enjoy the original picture at the highest level of realism.

■Noise Shaped Video (NSV)

The NSV feature works in the digital domain to reduce noise in the video signal frequency band in order to enhance video signal linearity.

Analog filter characteristics

Level

Noise level without NSV

			V
		ithNS
	lw		filter
Noise	leve
			+analog
	with		NSV
level
Noise

Frequency

Fig 1. Noise Shaped Video (NSV) Characteristics

■Super Sub Alias Filter

The S/N ratio can be improved when unwanted signals of higher than

6.75MHz following D/A conversion are cut. The DVD-A1 thus uses a Super Sub Alias Filter that produces flat characteristics, ensuring that adverse influences do not affect video signals inside the essential fre- quency band, and folding noise is eliminated. In the DVD-A1, the Super Sub Alias Filter is applied to the chroma signal as well as the

luminance signal, improving color reproduction.

		Analog filter			Signal loss and phase characteristics degradation occur here
Video		signal	Video noise			Video noise	Video noise	Video noise
		13.5		27		54		108 MHz
					Noise mixes in
	27 MHz Sampling
			Signal loss and phase characteristics degradation occur here
					Analog filter
Video		signal				Video noise		Video noise
		13.5		27		54		108 MHz
	54 MHz Sampling
	Sufficiently flat characteristics
	in the required frequency range
			Super Sub Alias Filter
						Analog filter
Video		signal						Video noise
			Ample cutoff characteristics
		13.5		27		54		108 MHz

108 MHz Sampling and Super Sub Alias Filter

Fig 2. Super Sub Alias Filter Characteristics

■A Wealth of Picture Quality Adjustment Functions

Contrast, Brightness, Hue, Sharpness, and Gamma can be adjusted as desired by the user.

■AL24 Processing Plus

Denon has further developed its proprietary AL24 Processing, an analog waveform reproduction technology, to support the 192-kHz sampling frequen- cy of DVD-Audio. This new technology, AL24 Processing Plus, thoroughly suppresses quantization noise associated with D/A conversion of LPCM sig- nals to reproduce the low-level signals with optimum clarity that will bring out all the delicate nuances of the music.

■24-bit, 192-kHz Audio D/A Converters

The DVD-A1 uses 8 Burr-Brown PCM-1704, high-performance 24-bit, 192-kHz D/A converters to faithfully and accurately enable high-quality performance required for any multi-channel playback. Each main chan- nel(FL/FR) have 2 DACs per channel in a differential configuration, while the Center/Surround Left/Surround Right/Subwoofer channels receive one per channel.

■Pure Direct Mode

The DVD-A1 includes two Pure Direct modes that further improve sound quality. For example, during analog audio output, Pure Direct can turn off digital signal outputs, video signal outputs, and the front panel display which can easily influence the sound quality of the analog audio signals. The user can define which operations are to be turned off and store those preferences in memory.