Arcam AVR400 service manual

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Q914 and Q915 (on the underside of the PCB) send BYPASS_ON and BYPASS_OFF logic signals from IC906 to the array of 4 x 20-bit non-inverting line driver/bμFfers with tri-statable outputs, IC911/912 and IC915/916. These are arranged as a 40 way 2-in, 1-out fast switch to bypass IC906 when required (e.g.

if 3D video is present). The video is in 12-bit RGB format and 4 more bμFfers are required for the video clock, H and V syncs and the DE (data enable) line, thus using up all of the available 40 ways. See sheet 9 of the schematic diagram. Power is provided via local L-C decoupling from +3.3VH2.

The HDMI output is handled by IC918, an Analog Devices ADV7511 in a 100 pin LQFP package. It is a 225MHz output part that can handle 12-bit 1080p video (up to 165MHz clock speed) and embedded HD audio. It is compatible with certain parts of the HDMI 1.4 specification, supporting 3D video and an ARC (audio return channel).

As with the other Analog Devices parts IC918 uses two power rails, namely +1.8VH2 and +3.3VH2. The necessary decoupling capacitors are mounted on the underside of the PCB.

In the AVR400’s implementation the HDMI audio output is limited to stereo rather then 8 channels – via I2S0 (pin 12), plus MCLK (pin 11), SCLK (pin16) and LRCLK (pin 17). SPDIF from the AVR400 is input to pin 10.

The ARC signal, if received from a downstream sink such as a TV, is output from pin 46 of IC918 and sent via back to the input board. Note that IC921 is not fitted.

The HDMI output is via JK97, a type A HDMI socket. As the AVR400’s output is partly HDMI 1.4 compliant, pin 14 now becomes the HEAC+ and pin 19 HEAC- as well as HPD (Hot Plug Detect). However, because the Ethernet part of the HDMI1.4 specification is not supported by the AVR400, the ARC is configured by the sink to be carried in single (i.e. non-differential) mode using HEAC+ as the signal line. HEAC+ and HEAC- are then AC coupled to pins 52 and 51 of IC918 via the 1μF series capacitors C439 and C428. R771, R777, R785, R795 and R799 bias the inputs and load the cable correctly.(Note – HEAC is short for HDMI Ethernet and Audio (return) Channel).

Q916 is a twin n-channel MOSFET which only turns on when +5VH1 is present. This isolates the DDC clock and data lines when the AVR400 is turned off.

IC917 is a low dropout voltage regulator feeding +5V power to pin 18 of JK97 from the +8VA supply, when enabled by the SW_P+5V line.

Analogue video output of digitized and processed 10-bit video from IC906 is available from the AVR400 via the video encoder IC919 – an Analogue Devices ADV7342B. Composite, s-video and component video are supported, although only component analogue video is output by the AVR400.

IC919 is in a 64 pin LQFP powered from the +18VA and +3.3VA lines. Once again most decoupling com- ponents are on the underside of the PCB.

The 6 x 11-bit video DACs inside IC919 are each loaded with 300R to ground before being AC coupled to IC913. This is a JRC NJM2566 6-channel video amplifier for SD and HD signals, powered from the +5VA line. The FS_SEL signal on pin 17 sets the bandwidth on component video to 13.5MHz or 30MHz, to suit progressive SD or HD signals respectively. The composite and s-video bandwidths are fixed at 6.75MHz. The outputs go to the analogue video daughter board via the 30 way socket BN301.

Note that the composite and s-video outputs are not actually used in the AVR400 so are not wired beyond CN301 on the daughter board. The Y, Cr, Cb component video outputs are terminated with 75 ohm series resistors on the Analogue Video daughter board described next.

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Contents Issue AVR400 Main Assembly Transformer Power Power PCBs + Feet Rear Panel + PCBs AVR400 Power Amplifier Circuit Description Page AVR400 Main Power Supplies Circuit Description AVR400 Front Panel Board Circuit Description Page Analogue inputs, volume control and outputs AVR400 Input Board Circuit DescriptionSpdif inputs, ADCs, DACs and Audio DSPs Page System Control Microprocessors AVR400 RS232 board AVR400 Hdmi Input/Output Board Page Page AVR400 Analogue Video Board Vfdrst CN101Vfdclk 25 27 29 24 26 28Page Page Page Page 8V Total 904.33mA ADV7844 TTL OutputHdmi 24/30/36Bit FLI30336 Worst Measured Currents Change Value 33ohm--0ohmConnect pin3 OE1 OE2 S1 S0Input Output GNDAdcreg 1.8/3.3V SCALER&AnalogREGFRONTHDMIOption Schematic Diagram SBL IC83 IC81NJW1321FP1 LC74763M+15V 8CH Lch JK79 8CH Rch8CH SLch 8CH SRch 8CH Cch JK78 15VScrew Mark
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AVR400 specifications

The Arcam AVR400 is a high-performance AV receiver designed to provide an immersive home theater experience. As part of Arcam’s esteemed lineup, the AVR400 combines advanced technology with exceptional sound quality, catering to audiophiles and home cinema enthusiasts alike.

At the heart of the AVR400 is its impressive power amplification, providing 100 watts per channel across 7 channels, ensuring a robust performance capable of driving a wide range of speakers. This power output is complemented by a high-current design, which means the receiver can handle dynamic audio passages without distortion, offering clarity in both subtle and explosive soundtracks.

One of the standout features of the AVR400 is its support for various surround sound formats, including Dolby TrueHD and DTS-HD Master Audio. This allows for an unparalleled audio experience, transporting users right into the heart of the action. Additionally, the AVR400 is equipped with the latest HDMI inputs, ensuring compatibility with a multitude of high-definition sources, including Blu-ray players, gaming consoles, and streaming devices.

The AVR400 also boasts advanced video processing capabilities, supporting 4K pass-through as well as upscaling of lower-resolution content to 4K. This makes it an ideal choice for users looking to future-proof their home theater setup, as it can seamlessly integrate with modern 4K televisions while enhancing the quality of older content.

User-friendliness is another essential characteristic of the Arcam AVR400. It comes equipped with an intuitive on-screen menu system that simplifies the setup process. The inclusion of an automatic calibration system helps optimize speaker settings in accordance with the room acoustics, ensuring users achieve the best sound possible from their setup.

Furthermore, the network features of the AVR400 allow for streaming audio from various online services and wireless devices. Built-in support for DLNA enables users to access their media library wirelessly, while the USB input allows for direct playback from flash drives or external hard drives.

In terms of build quality, the Arcam AVR400 embodies the brand’s commitment to excellence. With a sleek design, high-quality materials, and an engineered chassis that minimizes vibration and interference, the AVR400 is not only visually appealing but also built to deliver performance over time.

In summary, the Arcam AVR400 is a feature-rich AV receiver offering a perfect blend of power, precision, and versatility. Whether for movie nights or music listening, it stands out as a reliable choice for those seeking high-quality audio and video reproduction in their home entertainment systems.
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