The S-video C and OSD C signals do not need a DC clamp as they will float to the same level due to the nature of the signal.

S-Video Multiplexer

Refer to circuit diagram L922 sheet 9

This contains the multiplexing for the S-Video signals. It operates in the same way as the composite multiplexer (Sheet 3 Video board) except two multiplexers are used for each signal to carry the independent Luma and Chroma signals.

IC800 and IC807 carry the main feed Luma and Chroma respectively. IC801 and IC806 carry the VCR record loop Chroma and Luma respectively. The Main feed is buffered by IC803 it then goes to the OSD insert sheet, the VCR output is buffered by IC802 and then output to the VCR connector.

Control of the Multiplexer is via serial to parallel shift registers IC804, IC805 and IC808 these also have the control lines for the SCART control signals, sync on green and the Mute signals.

Zone 2 OSD

Refer to circuit diagram L922 sheet 10

This contains the OSD sync stripper and OSD insert circuits for Zone 2. It works in a very similar way to the circuits on sheets 4 and 8 combined together. As Zone 2 only operates in composite the circuit is without the extra multiplexing for S-Video and Component signals.

The Zone 2 video comes from the video input sheet 3 buffer it is terminated on this sheet then fed to both the OSD chip IC900 and the OSD insert multiplexer (Pixel Switch)IC902. Characters are generated by the OSD and this signal is present on the second input to the pixel switch. Both of the signal are sync tip clamped by transistors Q900, Q901, this means that their DC levels at the input to the pixel switch should be about the same.

The fast blanking signal from the OSD controls the position of the pixel switch. Fast blanking is high when OSD characters are being generated this causes the pixel switch to change to the output from the OSD chip. The pixel switch IC902 has a video buffer output and a gain of two. This buffered output is fed back to the Video board (sheet 3) and out via the Zone 2 connector.

The vertical sync output of the sync separator IC901 is used to determine if the incoming video is PAL or NTSC so that the correct clock can be provided to the OSD chip.

!Vertical sync 50Hz = PAL 17.73447MHz

!Vertical sync 60Hz = NTSC 14.31818MHz

Page 107 Page 109
Page 108
Image 108
Arcam AV8 Video Multiplexer Refer to circuit diagram L922 sheet, Zone 2 OSD Refer to circuit diagram L922 sheet
Page 107 Page 109

AV8 specifications

The Arcam AV8 is a high-performance audio-video receiver that has garnered attention for its exceptional sound quality and versatile features, making it a sought-after option for both audiophiles and home theater enthusiasts. Designed to provide an immersive viewing experience, the AV8 is equipped with a range of technologies that enhance its performance.

One of the standout features of the Arcam AV8 is its support for high-definition audio formats. The receiver can decode various lossless audio formats, including Dolby TrueHD and DTS-HD Master Audio, allowing users to experience studio-quality sound. This capability is complemented by its advanced digital signal processing, which ensures that the audio output is clear and dynamic, enhancing the overall entertainment experience.

The AV8 is built with an emphasis on connectivity and flexibility. It boasts multiple HDMI inputs and outputs, facilitating seamless connections to a variety of devices such as Blu-ray players, gaming consoles, and streaming devices. With support for 4K video pass-through, the AV8 is future-proofed for high-definition content, ensuring compatibility with the latest video technologies.

Another notable aspect of the Arcam AV8 is its user-friendly interface. The receiver is equipped with an intuitive on-screen display that simplifies navigation and setup. Additionally, Arcam has incorporated room calibration technology, which analyzes the acoustic properties of the listening environment and adjusts the audio output accordingly. This feature allows for optimal sound reproduction, tailored to the specific characteristics of the room.

The build quality of the AV8 is exceptional; it features a robust chassis designed to minimize vibration and interference, ensuring high-fidelity sound reproduction. The receiver is designed for ease of use, with remote control functionality and smart home integration options, making it convenient to operate alongside other devices.

In summary, the Arcam AV8 is a powerful AV receiver that combines high-definition audio capabilities, extensive connectivity options, and user-friendly features. With its strong emphasis on sound quality and innovative technologies, it stands out in the competitive landscape of home theater equipment, catering to the discerning tastes of audio enthusiasts and casual users alike. Whether for music or movie playback, the AV8 offers a compelling solution for those seeking an elevated audio-visual experience.
Top Page Image Contents