Arcam AV8 service manual Block Diagram

AV8 Audio Board

Introduction

This board forms part of the AV8 Preamp Processor, it performs analogue input selection and routing of analogue signals to the various outputs. There are four sets of outputs; main, zone2 and two tape loops “Tape” and ”VCR”. Main and zone2 outputs have volume controls (either of which can be the source for the on-board headphone amplifier). A gain ranging stage in the middle of the audio path sets the headroom of the signal chain and also provides a feed to the A-D converter on the digital board.

Control of the board is via the host micro-controller on the digital board.

BLOCK DIAGRAM

Stereo inputs

22			22	2	Tape out
			Record loop buffers
2			2
2				2	VCR out
			2
2
22	Mux
2			2	Volume	Mute	2
2	Input
2			2
					Headphone amp
2
2				Headphone select		2
22
2	2					2
2				To ADC	Mute
	Gain range		2
	Internal DAC L/R		2	2
External SACD input L/R			2		Volume
			Multichannel Mux
Internal DAC Surround			6
/Centre / Sub channel inputs				6		6
			6
External SACD Surround					Mute
/Centre / Sub channel inputs					Volume
	n	Signal bus where n is the number of audio channels
	Key:

ZONE2

Headphone

MAIN L/R

Surround/

Centre/

Sub outs