Meridian America Meridian 518 manual Planning setup, Whats inside a 518?

Page 7

Overview of 518

7

 

 

Planning setup of 518

Firstly, the 518 is a product for enthusiasts! We designed it for audio and multimedia enthusiasts, keen listeners and those with enthusiasm for the best sound.

However, 518 is something of a chameleon. What do we mean by that? This is best explained by seeing what it does: 518 fulfils four very different functions in one box.

We have categorised uses (applications) of 518 into four broad headings, as follows:

A simple 'preamp' orControl Unit for a purist digital audio system. (Type 0) – see below.

A Resolution Enhancement processor in a high-quality audio system. (Type 1) – see the overviews on pages 10 and 49.

A Mastering Processor, used in any recording, editing, mastering or dubbing process. (Type 2) – see the overview on page 12.

A peri-computer Multimedia Processor. (Type 2) – see the overview on page 12.

What's inside a 518?

D1

D2

D3

Opt

RS232

 

Input Switch

 

 

 

 

 

 

 

 

Twin PLL

 

 

42MHz DSP

 

 

Digital Output

 

Out

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Front Panel

 

 

 

 

 

 

 

 

Control

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Computer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Internal block diagram for 518

518 is a 2-channel digital audio computer with four inputs – see the diagram above. The selected input is de-jittered with a proprietary Meridian twin phase-lock-loop that acts as a 'big flywheel' to regulate the audio stream. By using this twin PLL we ensure that the outgoing digital audio has very precise timing allowing the final output device (e.g. DAC) to achieve its maximum sonic potential.1

Following the twin PLL is a fast (42MHz) 24-bit Digital Signal Processor, which runs the user programs in 518. The DSP functions are all controlled by an internal computer which co-ordinates the front-panel keys, remote control sensor and display as well as RS232 control.

All software for 518 – control and DSP is held in a socketed EPROM. This allows the potential of upgrades or new applications being issued later.

Following the DSP is a multistandard digital output.

1For the technically interested, Figure 1 on page 49 shows the performance of the twin PLL.

518 User Guide

Image 7
Contents 1992, 1993 Contents Appendix 4 -Resolution Enhancement Simple rules for usingAppendix 2 Hints on Mastering Acknowledgements Sales and service in the UKSales and service in the USA Designed & manufactured in the UK byConventions used in this manual IntroductionAbout this manual About the 500 SeriesConnections Installing yourGeneral precautions UnpackingWhats inside a 518? Planning setupOverview as Preamp Type What else do I need to know? What about analogue sources?CD or LaserDisc playback improvement Overview as Resolution Enhancement Processor TypeMeridian DSP speaker improvement Meridian Surround improvement Overview as Multimedia Processor Type Overview as Mastering Processor Type∙ Normal ∙ Standby ∙ Type ∙ Config Customising featuresStandby Switching onStarting off with Basic operationOut Adjusting the volumeOperating 518 as a Control Unit Type Selecting a sourceShape B DitherFlat Shape aDisplay Advanced operation using the Remote Control Menu Keys Operating 518 as Resolution Enhancer TypeVolume control Muting the soundOperation summary With the Remote ControlMemory Customising 518, an overview Restoring default settingsConfig an overview Config control settingsHow to change to Type or Config How to customiseCustomising, general procedure Config sources and inputsSetting Type Controller Customising using TypeHow to change back to Normal Making changes to an existing setupSelecting Types Customising using ConfigHow to use Config ConfigSetting the Standby mode for Selecting the controller modeSetting the system address for Setting the product address forSetting the Volume display Setting the Blank display option forSetting the Emphasis option for Setting the Volume mode forChoosing source logos Setting up sourcesVol. dB Choosing the Comms type for a source product Changing the input for a sourceChoosing the address of a source product Digital output connection ConnectionsDigital audio connections Digital input connectionsCon Connecting to Meridian Digital speakersCommunications connections To connect to other Meridian 500 Series equipmentMastering Processor PartD1 +2 DescriptionAs a Mastering or Multimedia Processor Type Meridian 500 Comms warningShpB +2 Emph +2Making Recordings Transfer to the final carrier Transfer to editorShaper Advantage 44.1kHz 48kHz Normal Pre-emphasis Noise shaper characteristicsDither Operating BackgroundTransparency in digital systems Digital Audio and QuantisationDynamic Range Noise Shaping with ditherPre and De-emphasis Step up in dynamic range Simple rules for usingStep-down in sample word size No change in sample sizeAdditional technical information SpecificationHelp Maintenance & Service CleaningNoise Part Appendix 1 Noise ShapesAbove noise spectrum for Shape B at 44.1kHz 0Hz 5kHz 10kHz 15kHz 20kHz Requirements for D/A conversion Vulnerability of the signalAudible results of digital errors and editing Appendix 2 Hints on Mastering with noise-shapingAppendix 2 Hints on Mastering Handset Functions Appendix 3 RS232GoTo Functions Jitter and de-jittering Appendix 4 -Resolution EnhancementFrequency Dynamic-rangeDynamic-range optimisation with Pre-emphasis Dynamic-range optimisation with GainShowing CD pre- and de-emphasis curves Dynamic-range optimisation with Noise-shaped Dither DAC or channel enhancement by word-length matching DAC enhancement by using high-frequency ditherIndex ContentsIndex User Guide User Guide