Manuale d’uso / di manutenzione del prodotto Digital Audio Processor 518 del fabbricante Meridian
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MERIDIAN 518 USER MANUAL © 1992, 1993, 1995.
2 518 User Guide Contents Sales and service in the UK ................... 4 Sales and service in the USA ................. 4 Designed & manufactured in the UK by ................................ .................. 4 Acknowledgements ..............
3 518 User Guide Simple rules for using 518 .................. 40 Additional technical information ......... 42 Specification ......................................... 42 Help! ...................................................... 43 Standby point not lit .
4 518 User Guide Sales and service in the UK Meridian Audio Ltd Stonehill Huntingdon Cambs. PE18 6ED England Tel (0) 480 52144 Fax (0) 480 459934 Sales and service in the USA Meridian America Inc. 3800 Camp Creek Parkway Building 2400, Suite 112 Atlanta, GA 30331 Tel.
Installation 5 518 User Guide Introduction The Meridian 518 Digital Audio Processor is part of the 500 Series of advanced high-fidelity equipment. In purchasing a Meridian 518 Digital Audio Processor, you have acquired a re fined piece of equipment that will continue to bring you listening pleasure for many years.
Installation 6 518 User Guide Part 1 Unpacking the 518 On opening the carton, you should have found the following parts: • Meridian 518 Digital Audio Processor • Power cord • This manual • 500 Series communications lead If any of these items is missing, please contact your dealer.
Overview of 518 7 518 User Guide 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.
Overview of 518 8 518 User Guide Overview as Preamp (Type 0) Conventional analogue systems use a 'preamp' or control unit to gather together the various sources and to control the level of signal fed to the power amplifier so you can adjust volume.
Overview of 518 9 518 User Guide What about analogue sources? 562 518 CD Player LaserDisc DAT LP Tuner Using 518 with a 562 Analogue sources need to be converted to digital before passing through 518. Meridian make the 562 and 562V digital controllers, both of which have very high quality delta-sigma analogue – digital converters.
Overview of 518 10 518 User Guide Overview as Resolution Enhancement Processor (Type 1) There are a wide number of applications for this mode of 518: three examples are described. CD or LaserDisc playback improvement Many installations use the 2-box CD player format of CD transport + DAC.
Overview of 518 11 518 User Guide 562 518 CD Player LaserDisc DAT LP Tuner DSP Speaker DSP Speaker Using 518 with DSP Loudspeakers As the diagram shows, a 518 can be placed between the 562 and the Meridian DSP speakers.
Overview of 518 12 518 User Guide Overview as Mastering Processor (Type 2) Using 518 as a Mastering Processor 518 Recorder ADC DAT Recorder Mixer The 518 is closely related to the highly respected Meridian 618 Mastering Processor; in fact 518 uses identical DSP to the 618 in this mode.
Overview of 518 13 518 User Guide • De-jittering. This is vital to getting good sound when recording or playing back from a computer-based sound storage system. • Matching wordlengths input to output. Hard disc storage systems tend to use 16 or 24 bits.
Using 518 in Hi Fi Systems 14 518 User Guide Starting off with 518 Checking Before turning on the power, check once again that you have made all the connections correctly. The 518 is designed to be left connected to AC power at all times and can be run continuously.
Using 518 in Hi Fi Systems 15 518 User Guide Note 518 can be used with or without other Meridian equipment. When it is used as the main system control unit it is normally the ‘System Controller’ and operates exactly as described below.
Using 518 in Hi Fi Systems 16 518 User Guide The numbers indicate the number of output bits. C and P represent the choice of consumer and professional channel status formats respectively.
Using 518 in Hi Fi Systems 17 518 User Guide Shape C uses flat dither and a 9th-order shaper optimised to MAF. Shape D uses high-pass dither and a 9th-order shaper optimised to MAF. Shape E uses high-pass dither and a 2nd-order shaper optimised to MAF.
Using 518 in Hi Fi Systems 18 518 User Guide 20C16 67 Input/output choice and gain setting, (This example indicates 20 bits of input and 16 bits of output in consumer format), or 44k1 67 Sampling frequency and gain. If there is no input signal the display would indicate no lock as follows: N.
Using 518 in Hi Fi Systems 19 518 User Guide Muting the sound The mute facility cuts off the sound by setting the volume level to zero. To mute the sound 1. Press Mute on the Remote Control. The output will mute and the display will change to: To restore the sound 1.
Operation summary 20 518 User Guide Memory In Resolution Enhancement mode, 518 maintains a continuous memory of the DSP, Dither, Gain, In and Out settings for each source.
Customising 518: overview 21 518 User Guide Customising 518, an overview 518 is a very sophisticated device with a huge number of options to allow you to set up exactly the system you need or to experiment with new possibilities. Programming 518 is a straightforward process and you should not be timid about experimenting.
Customising 518: overview 22 518 User Guide • whether or not the Bypass DSP option is available. 2 • whether or not a blank display option is allowed. • whether or not the Emphasis DSP option is adaptive – i.e. reacts to the incoming emphasis status.
Customise 518 using Type 23 518 User Guide Caution Some power amplifiers are very susceptible to small surges that may result from the process of switching a preamplifier on and off. Some – like the Meridian 205 or 605 incorporate DC-offset protection that may be triggered by this process.
Customise 518 using Type 24 518 User Guide • Source-Logo-input mapping as shown below. Source Logo Type 0 Input Type 1 Input Type 2 Input Comms type CD CD D1 D1 D1 1 Radio RD D1 D1 N 2 LP LP D1 D1 N.
Customising 518 using Config 25 518 User Guide Selecting the controller mode In Config mode: 1. Press Display until you see a display like: 2. Use the and , Volume keys to choose between: • Auto, meaning configuring can be automatic • Cont, meaning the 518 will be the system controller • N.
Customising 518 using Config 26 518 User Guide Setting the Blank display option for 518 In Config mode: 1. Press Display until you see a display like: This means that a blank display is one of the options offered by the Display key. To remove this option chose N.
Customising 518 using Config 27 518 User Guide The gain of 518 can either be displayed in absolute dB in the range -99dB to +12dB, or as a Meridian volume number 0 to 99 – where 87 corresponds to 0dB. 2. Use the and , Volume keys to choose dB or ##.
Customising 518 using Config 28 518 User Guide 3. Use the and Volume keys until the correct logo is indicated – see the list above. 4. Make changes for all the source options. Note If you select the logo ‘ N’ the 518 will ignore that key on the Remote control and that source will not be offered in the Normal source menu.
Connecting 518 29 518 User Guide Connections There are three types of connection that need to be made to the 518. • power, see page 14 . • digital audio, see page 40 .
Connecting 518 30 518 User Guide Communications connections Communications connections are only made to other Meridian equipment. The following sections describe the major points.
Using 518 for Mastering and Multimedia 31 518 User Guide Part 2 Mastering Processor The Meridian 518 Digital Audio Processor has been designed to allow the making of better recordings, and in particular to enable the production of high-quality, enhanced-definition CDs.
Using 518 for Mastering and Multimedia 32 518 User Guide Description The Meridian 518 Digital Audio Processor is a general-purpose digital- domain DSP engine that operates on or between consumer or professional interfaces at sampling frequencies between 32 – 50kHz and with up to 24 bit input and output.
Using 518 for Mastering and Multimedia 33 518 User Guide Memory In Mastering Processor mode, 518 maintains a continuous memory of the DSP, Dither, Gain, In and Out settings for each source.
Using 518 for Mastering and Multimedia 34 518 User Guide 20C16 +2 Input/output choice and gain setting, (This example indicates 20 bits of input and 16 bits of output in consumer format), or 44k1 +2 Sampling frequency and gain. If there is no input signal the display would indicate no lock as follows: N.
Using 518 for Mastering and Multimedia 35 518 User Guide • Out set to the number of bits in the recorder. Transfer to editor Case 5. The recording and editor are the same word size In this case use Bypass. Case 6. The recording has fewer bits than the editor In this case use Bypass.
About the Noise Shapers 36 518 User Guide Noise shaper characteristics Each noise shaper presents a different degree of subjective noise reduction – we call that its ‘advantage’ – compared with normal dithering using white TPDF dither. Each shaper also has a different degree of HF boost.
Additional technical information 37 518 User Guide 518 Operating Background Transparency in digital systems Digital audio gives a unique opportunity to deliver exceptional sound quality in a recording or broadcast. In the first decade of this technology, considerable progress was made developing the gateways – i.
Additional technical information 38 518 User Guide Unfortunately, although this process is generally understood, it is not common practise to employ correct dithering procedures at these stages.
Additional technical information 39 518 User Guide source, the average and peak spectrum level declines with frequency above a few kHz. Best use is therefore made of the channel by pre- emphasising high-frequency signals to an extent where they are more likely to occupy the capacity of the channel.
Additional technical information 40 518 User Guide the dynamic range of the signal itself. A typical application may be a full- range DSP volume control, where e.g. a 16 bit input is modified by a gain control function and passed out to a DAC of 18 or 20 bits.
Support information 41 518 User Guide Help! Standby point not lit Check the following: 1. There is AC power connected to the socket on the rear of the 518 2. The power switch on the rear panel of the 518 is turned on If the 518 will still not illuminate, check any fuses in your power supply and the fuse in the inlet of the 518.
Support information 42 518 User Guide FCC WARNING : This equipment generates and can radiate radio fre - quency energy and if not installed and used correctly in accordance with our instructions may cause interference to radio communications or radio and television reception.
Appendix 1 – Noise Shapes 43 518 User Guide Part 3 Appendix 1 – Noise Shapes The graphs in this appendix show the relative noise spectra in dB for the different shapers, compared with the flat-spectrum dither level for the same word-size.
Appendix 1 – Noise Shapes 44 518 User Guide 0Hz 5kHz 10kHz 15kHz 20kHz 25kHz -30dB -20dB -10dB 0dB 10dB 20dB 30dB 40dB Noise Spectrum F requency Above: noise spectrum for Shape B at 44.1kHz 0Hz 5kHz 10kHz 15kHz 20kHz 25kHz -30dB -20dB -10dB 0dB 10dB 20dB 30dB Noise Spectrum F requency Above: noise spectrum for Shape C at 44.
Appendix 1 – Noise Shapes 45 518 User Guide 0Hz 5kHz 10kHz 15kHz 20kHz 25kHz -30dB -20dB -10dB 0dB 10dB 20dB 30dB 40dB Noise Spectrum F requency Above: noise spectrum of shape D at 44.
Appendix 2 – Hints on Mastering 46 518 User Guide Appendix 2 – Hints on Mastering with noise-shaping There are a few difficulties associated with employing noise-shaping schemes to maximise the subjective dynamic-range of a digital audio channel. These are now reviewed.
Appendix 2 – Hints on Mastering 47 518 User Guide dynamic range is extended. Implicit in this theory is the fact that the digital channel has near-infinite differential linearity, i.e. each bit has a magnitude precisely twice or half the magnitude of the next.
Appendix 3 – RS232 48 518 User Guide Appendix 3 – RS232 The 518 may be operated via its RS232 interface. Set the communication settings as follows: • Baud rate 9600 • Data bits 8 • Stop bit 1 • Parity none The 518 is operated by sending short command strings on the RS232 interface.
Appendix 4 – Resolution Enhancement 49 518 User Guide Appendix 4 – Resolution Enhancement Resolution enhancement in 518 depends on six techniques. 1. De-jittering 2. Dynamic-range optimisation with Gain 3. Dynamic-range optimisation with Pre-emphasis .
Appendix 4 – Resolution Enhancement 50 518 User Guide The block diagram on page 7 shows the twin phase-lock-loop which 518 uses to smooth out the digital sample stream. Each loop acts as a progressive 'flywheel' – following the average sample rate exactly – but removing short-term speed unevenness.
Appendix 4 – Resolution Enhancement 51 518 User Guide Figure 3 . Showing the audibility of noise in the LP system for comparison with digital channels. Dynamic-range optimisation with Gain The noise-floor of a digital system is determined absolutely by the lowest preceding wordsize.
Appendix 4 – Resolution Enhancement 52 518 User Guide are boosted. This boost process is called pre-emphasis. Now, in the channel, the energy is more evenly distributed with frequency, and any high-frequency noise and distortion in the channel is further below the signal.
Appendix 4 – Resolution Enhancement 53 518 User Guide such converters are used. Meridian has always used correct analogue de- emphasis in its designs.
Appendix 4 – Resolution Enhancement 54 518 User Guide 10Hz 100Hz 1kHz 10kHz -20 0 20 40 60 80 100 d B sp l SBM Shape C Shape D Figure 6 . Showing the effect on audibility of the 518's Shapes C and D (C using pre-emphasis).
Index 55 518 User Guide Index 500-Series, 5 562, 9 565 using with, 11 Acknowledgements, 4 AES/EBU digital audio connections, 29 Analogue sources, 9 Autoconfigure, 30 Background noise, 41 Bypass, 33 Ca.
Index 56 518 User Guide Pre-emphasis explained, 38 Programming. see Customising Radio interference, 41 Recording, 34 Remote control, 18 Repacking 518. see Unpacking Resolution enhancement explained, 49 Resolution enhancer, 19 Restoring defaults, 21 RS232, 48 Service where to get, 42 Setup.
Notes 57 518 User Guide Notes.
Notes 58 518 User Guide.
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il Meridian Digital Audio Processor Meridian 518 è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del Meridian Digital Audio Processor Meridian 518 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso Meridian Digital Audio Processor Meridian 518 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul Meridian Digital Audio Processor Meridian 518 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il Meridian Digital Audio Processor Meridian 518, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del Meridian Digital Audio Processor Meridian 518.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il Meridian Digital Audio Processor Meridian 518. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo Meridian Digital Audio Processor Meridian 518 insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
