Lexicon Converter Manuale Utente Pagina 1

20/20 AD20 Bit A/D ConverterUser Guide

5Controls and Connectors20/20 AD User GuidePUSHDOWORD CLOCKINDO3 + 4 1 + 2OUTAESSYNCINV ~PUSH4IN3UNBALBALPUSH PUSH2IN1UNBALBALPUSHDigital OutputTw

Lexicon6Controls and ConnectorsAudio ConnectionsXLR PinoutSignal Mating Connector DescriptionAES/EBU XLR A3M Balanced RS-422Digital InputAES/EBU XLR A

7Controls and Connectors20/20 AD User GuideAES/EBUDigital OutputThis interface requires balanced connections using high-quality, low-capaci-tance, con

9Using the 20/20 AD20/20 AD User GuideAnalog InputsThe 20/20 AD has four analog inputs: CH1, CH2, CH3 and CH4. In two-channelmode, only CH1 and CH2 ar

Lexicon10Using the 20/20 ADJumper settings(as set at the factory)W18CHASSIS GROUNDANALOG INAES SYNC INWORD CLOCK INAES OUTS/PDIF OUTXLRCONNECTORSHIEL

11Using the 20/20 AD20/20 AD User GuideThe following figure indicates the locations and factory settings of these jumperson the board. In their closed

Lexicon12Using the 20/20 ADMake sure the BALANCE switches located on the rear panel are set to matchthe type of input. (OUT=balanced , IN=unbalanced).

13Using the 20/20 AD20/20 AD User GuideAdjust the front panel Gain knobs until the peak input levels are balanced andcome within a few dB of clipping.

Lexicon14Using the 20/20 ADThe 20/20 AD can synchronize to its internally derived sample clock at 44.1kHzor 48kHz, or to an external AES or Word Clock

15Using the 20/20 AD20/20 AD User GuideThe 20/20 AD is shipped configured for Internal mode. To operate in Externalmode, press EXT SYNC until the desi

LexiconCopyright © 1994 Lexicon Inc.100 Beaver StreetWaltham MA 02154-8441 USA617-736-0300Fax: 617-891-0340All Rights ReservedThis publication is pr

Lexicon16Using the 20/20 ADAbout DitherDither is a low-level pseudo-random signal which is added to digital audio toreduce quantization noise, in effe

17Using the 20/20 AD20/20 AD User Guide-160.0-150.0-140.0-130.0-120.0-110.0-100.0-90.00-80.00-70.00-60.000.0 2.00k 4.00k 6.00k 8.00k 10.0k 12.0k 14.0k

Lexicon18Using the 20/20 ADAutomatic OffsetRemovalDC offsets are created by input amplifiers and A/D converters for a number ofreasons. In the 20/20 A

19Using the 20/20 AD20/20 AD User Guide___| threshold |___| threshold| – gainratio =Note that the 6dB GAIN setting is given only as an example. Feel f

Lexicon20Using the 20/20 AD0dB-3dB-6dB-8dB-10dB-12dB-14dB-16dB-18dB-20dB-22dB-24dB-26dB-30dB-36dB11.50:11.20:11.14:11.11:11.09:11.07:11.06:11.06:11.05

21Using the 20/20 AD20/20 AD User GuideWhen RELEASE is set to 0, the compressor acts like an amplifier with a non-linear transfer function. For exampl

Lexicon22Using the 20/20 ADTo summarize:1. Set the input levels so that the peak level is a few dB below clipping.2. Turn on the compressor.3. Set com

23Using the 20/20 AD20/20 AD User GuideIn 2-channel mode, when the LINK switch is off, each of the two channels iscompressed independently. When the L

Lexicon24Using the 20/20 ADWhen recording in 4-channel mode to two DAT recorders, it may be useful torecord a "clapper" signal to both DATs

25Using the 20/20 AD20/20 AD User GuideOperating the 20/20 ADin the Digital ModeThe 20/20 AD's Digital Input mode can be used to make use of the

20/20 AD User GuideSAFETY SUMMARYThe following general safety precautions must be observed during all phases of operation, service andrepair of this i

2720/20 AD User GuideDigital AudioInputs and OutputsAES, S/PDIF: XLR, 3-wire balancedRCA, 2-wireunbalanced coaxial lineOptical, optical fiberWord Clo

Definition of Terms2920/20 AD User GuideDefinition of TermsAES : Audio Engineering Society.aliasing : a form of distortion which occurs when an A/Dco

20/20 AD User GuideContentsIntroductionControls and Connectors ...1Unpacking • Powe

20/20 AD User GuideIntroductionThe 20/20 AD is an analog-to-digital converter which can be configured fortwo 20-bit channels, or four 18-bit channels.

1Controls and Connectors20/20 AD User GuideAfter unpacking the 20/20 AD, save all packing materials in case you ever needto ship the unit. Thoroughly

Lexicon2Controls and Connectors1dB SCALEALTPK HOLDATTEN1THRESHUNBAL THRESHUNBAL2 3THRESHUNBAL THRESHUNBAL44 CHAN~EMPHOVL03612182430364260OVL036

3Controls and Connectors20/20 AD User GuideThe Level MetersWhen the compressor is off, the behavior of the level meters is determined by the settingso

Lexicon4Controls and ConnectorsSynchronization andOutput FormattingAlternate ModesSAMPLE RATESelects the sample rate ofthe A/D conversion. Thisswitch