ADC ADDC1 manuale d’uso

ADC1 Instruction Manual Page 1 Benchmark ADC1 Instruction Manual 2-Channel 24-bit 192-kHz Audio Analog-to-Digital Converter[...]

ADC1 Instruction Manual Page 2 Federal Communications Commission (FCC) Notice (U.S. Only) NOTICE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limit s are designed to provide reasonable protection against harmful interference in a residen tial installa t[...]

ADC1 Instruct ion Manual Page 3 Contents Overview 4 Features 6 Connections 7 Balanced Analog Line Inputs 7 Clock Reference Input 7 Digital Outputs 8 AES/EBU XLR Output 8 Optical Output 8 SPDIF/AES BNC Main a nd Aux Outputs 9 Word Clock Reference Output 10 AC Power Entry Connector 10 Fuse Holder 10 Operation 11 Mode Switch and Display 11 Programming[...]

ADC1 Instruction Manual Page 4 Overview The ADC1 is a referenc e-quality, 2-ch annel 192-kHz 24-bit audio analog-to-digital converter featuring Benchmark’s UltraLock ™ technology. The ADC1 is designed for maximum transparency. It is w ell suited for the most demanding applicat ions in studios and mastering facilities. A rugged and compact half-[...]

ADC1 Instruction Manual Page 5 The Auto mode allows the ADC1 to lock to an external clock referenc e. In Auto mode, the ADC1 will follow changes in sample rate, and/or changes in the ty pe of reference signal (AES, SPDIF, word cl ock, or super clock). When a clock reference is not available, the Internal mode must be used, and a sample- rate must b[...]

ADC1 Instruction Manual Page 6 Features • Two analog-to-digital conversion channels • Two XLR balanced analog in puts providin g high-performance over a 43 dB range • -14 dBu to +29 dBu input sensit ivity range (at 0 dBFS) • Two 0 dB, 10dB, and 20 dB first-stag e gain switches (1 per channel) • Two 41-detent gain controls with a 20 dB ran[...]

ADC1 Instruction Manual Page 7 Connections Main 24-Bit Digital Outputs Aux 24 or 16-Bit Digital Output Analog Line In AES/EBU AD A T/SPDI F SPDI F , AES WC Out AES, WC, SC Ref In Left Right Balanced Analog Line Inputs (XLR) Auxiliary Digital Output, BNC (AES) Clock Reference Input, BNC (AES, W ordclock, Superclock) W ordclock Reference Out p ut, BN[...]

ADC1 Instruction Manual Page 8 Digital Outputs The ADC1 has four digital audio outputs: three Main Outputs and one A ux Output. Main Outputs • XLR connector, balanced, AES/EBU professional format, 24-bits • BNC connector, un-balanced, AES/EBU professional format, 24-bits, compatible with most SPDIF inputs • Optical TOSLINK connector, multi-fo[...]

ADC1 Instruction Manual Page 9 ADAT Optical Output Mode • Data Format = ADAT • Word Length = 24 bits • Sample Rate = 44.1 or 48 kHz • Clock Source = Inte rnal or external • ADAT channel assignments: 1 = Left, 2 = Right, 3-8 = muted ADAT S/MUX 2 Optical Output Mode • Data Format = ADAT • Word Length = 24 bits • Sample Rate = 88.2 or [...]

ADC1 Instruction Manual Page 10 Word Clock Reference Output This output provides a Word Clock signal for use with downstream c omponents. AC Power Entry Connector The AC power input use s a standard IEC type connector. Within the USA and Canada, the ADC1 ships with a powe r cord. In other locations, a location-specific IEC style power cord may be p[...]

ADC1 Instruction Manual Page 11 Operation Mode Display Mode Switch Meter Display Meter Switch Left First Stage Gain Right First Stage Gain Left V ariable/Calibrated Gain Switch Right V ariable/Calibrated Gain Switch Left Gain Preset Right Gain Preset Left Gain Right Gain Mode Switch and Display The ADC1 can be progr ammed to function in a variety o[...]

ADC1 Instruction Manual Page 12 Off = Internal Sync On = Locked to Exter nal Sync Flash = External Sync Selected but Not Locked The bottom left LED in the Mode Display is the Ext Indicator. It shows that the ADC1 is locked to an external clock source. If the Ext LED is off, then the ADC1 is set to operate at a fixed sample rate using th e internal [...]

ADC1 Instruction Manual Page 13 Programming the Aux Output The Aux Output can be programmed to mirror the Main Outputs (bit for bit), or it can provide an independent low- resolution copy of the converted signal, at an independent sample rate. Column three of the Mode Indicator displays the A ux Output mode setting. Note that no matter how t he Aux[...]

ADC1 Instruction Manual Page 14 The red 0 LED indicates that a full-scale digital code has been re ached and that digital clipping has occurred. Fu ll-scale event s as short as one digital sample, will light the 0 LED. Short single-sample digital clipping events are often audi ble, and all 0 dBFS events should be avoided. The ADC1 has a very large [...]

ADC1 Instruction Manual Page 15 Down Position Rack Mounting To enable rack mounting, the front panel of the ADC1 has rack-mo unt holes that are machined to conform to standard rack mount dimensions. The width of the ADC1 panel is exactly ½ that of a standard 19” panel. The ADC1 is one rack unit high. Ei ther ear of the ADC1 can be mounted direct[...]

ADC1 Instruction Manual Page 16 Using ADA T S/MUX Proper S/MUX Identification is a Must S/MUX 2 allows recording 4 channels at 88.2 or 96 kHz using a standard 8-channel 44.1 or 48 kHz ADAT recorder. S/MUX 4 allows recording 2 channels at 176.4 or 192 kHz using a standard 8-channel 44.1 or 48 kHz ADAT recorder. In either case it is important to iden[...]

ADC1 Instruction Manual Page 17 UltraLock™ … What is It? Accurate 24-bit audio conversion requires a very low-jitter conversi on clock. Jitter can very easily turn a 24-bit converter into a 16- bit converter (or worse). There is no point in buying a 24-bit convert er if clock jitter has not been adequately addressed. Jitter is present on every [...]

ADC1 Instruction Manual Page 18 How does conversion clock jitter degrade converter performance? Problem #1 Jitter phase modulates th e audio signal. This modulation creates sidebands (unwanted tones) above and below every tone in the audio signal. Worse yet, these sidebands are often widely separated from the to nes in the original signal. Jitter-i[...]

ADC1 Instruction Manual Page 19 Is it possible to eliminate all of the effects of jitter in an entire digital audio system? Interface jitter will accu mulate throug hout even the most carefully designed digital audio system. Fortunately, interface jitter can only degrade digital audio if it affects the sampling circuit in an analog-t o-digital or a[...]

ADC1 Instruction Manual Page 20 Performance Frequency Response The above graphs show the frequency respon se of the ADC1 when it is operating at a 192-kHz sample rate. Note that the ampl itude response is down by less than 0 .05 dB at 10 Hz and 80 kHz. The bass response extends well below the 10-Hz limitation of the measur ement equipment, and the [...]

ADC1 Instruction Manual Page 21 Inter-Channel Phase Response This graph shows that the dif ferential phase is significan tly better than ± 0.25º f rom 10 Hz to 20 kHz.[...]

ADC1 Instruction Manual Page 22 THD+N vs. Level, 1 KHz w/20 kHz LPF unweighted Below –4 dBFS, distortion is lower than the noise fl oor of the converter. Ab ove –3 dBFS, distortion reaches a maximum value of only –107 dBFS.[...]

ADC1 Instruction Manual Page 23 32K B-H FFT, Idle Channel Noise The above graph demonstrates that the ADC1 i s free from idle tones and clock crosstalk. T he highest spurious tone measures –128 dBFS and is AC line related hum. The highest non-line related tone measures –135 dBFS.[...]

ADC1 Instruction Manual Page 24 32K B-H FFT, -3 dBFS, 1 KHz The above FFT plot shows that the ADC1 has very little harmon ic distortion. Distortion is exceptionally low and is dominated by 2 nd harmonic distortion. Note t he near absence of spuri ous tones.[...]

ADC1 Instruction Manual Page 25 32K B-H FFT, -3 dBFS, 10 KHz The above FFT plot shows that the ADC1 is fre e fr om jitter-induced sid eband s. Any jitter present at the conversion sampli ng circuit would produce si debands equally spaced above and below the 10 kHz test tone. The tone at 20 kHz is due to second harmon ic distortion, and measures alm[...]

ADC1 Instruction Manual Page 26 Specifications Analog Audio Inputs Number of Inputs (balanced) 2 Connector Gold-Pin Neut rik™ female XLR Impedance 200 k Ω Sensitivity -14dBu to +29 dBu (a t 0 dBFS) Clock Reference Input Format Auto-detect AES/EB U, Word Clock, and Super Clock (256x) Impedance 75 Ω Sensitivit y 150 mV AES 200 mV Word Clock 750[...]

ADC1 Instruction Manual Page 27 Digital Audio Outputs Number of Digital Outputs 1 XLR Main 1 TOSLINK Main 1 BNC Main 1 BNC Aux Connectors Gold-Pin Neut rik™ male XLR Number of Audio Channels 2 Main Output Word Length 24 bits Main Output Sample Frequencies 44.1, 48, 88.2, 176.4, or 192 kHz Aux Output Word Length 16 or 24 bits Aux Output Sample Fre[...]

ADC1 Instruction Manual Page 28 Audio Performance Fs = 44.1 to 192 kHz, 20 to 20 kH z BW, 1 kHz test tone, 0 dBFS = + 24 dBu (unless noted) SNR – A-Weighted, 0 dBFS = +8 to +29 dBu 121 dB SNR – Unweighted, 0 dBFS = +8 to +29 dBu 119 dB SNR – A-Weighted at max gain, 0 dBFS = -14 dBu 108 dB THD+N, 1 kHz at –1 dBFS -102 dBFS, -101 dB, 0.00089%[...]

ADC1 Instruction Manual Page 29 Jitter Toleran ce (With no Measu rable Change in Performance) >12.75 UI sine, 100 Hz to 10 kHz > 3.5 UI sine at 20 kHz > 1.2 UI sine at 40 kHz > 0.4 UI sine at 80 kHz > 0.29 UI sine at 90 kHz > 0.25 UI sine above 1 60 kHz Maximum Amplitude of Jitter Induced Sidebands < -134 dB (measurement limit [...]

ADC1 Instruction Manual Page 30 AC Power Requirements Input Operating Voltag e Range (VAC RMS) 110 V setting – 95 V min, 140 V max 220 V setting – 190 V min, 285 V max Frequency 50-60 Hz Power 16 Watts Idle 16 Watts Typical Program 20 Watts Maximum Fuses 5 x 20 mm (2 required) 110 V setting – 0.5 A 250 V Slo-Blo ® Type 220 V setting – 0.5 [...]

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ADC1 Instruction Manual Page 32 W arranty Information Benchmark 1 Year Warranty The Benchmark 1 Y ear W arranty Benchmark Media Systems, Inc. warrants its produc ts to b e free from defects in material and workmanship under normal us e and service for a period o f one (1) year from the date of delivery. This warranty ext ends only to the origin al [...]

ADC1 Instruction Manual Page 33 Benchmark Extended Warranty The Benchmark Extended 5* Y ear Warranty Benchmark Media Systems, Inc. optionally extends the standard one (1) year warranty to a period of five (5)* y ears from the d ate of delivery. *For the extended warranty to become effectiv e, the original purcha ser must register the product at the[...]

ADC1 Instruction Manual Page 34 Copyright © 2005 Benchmark Media Systems, Inc. All rights reserved. Benchmark Media Sy stems, Inc. 5925 Court Street Road Syracuse, NY 13206-1707 USA +1-315 437-6300, FAX +1-315-437-8119 http://www.benchmark media.com[...]