digital audio weiss engineering ltd. Florastrasse 42, 8610 Uster, Switzerland +41 44 940 20 06 +41 44 940 22 14 http://www.weiss.ch / http://www.weiss-highend.com WEISS GAMBIT ADC2 OPERATING MANUAL Software Version: 3.1 Firewire option update 12.10.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER INTRODUCTION INTRODUCTION Congratulations on purchasing the Weiss Gambit Series ADC2 A/D Converter ! The ADC2 is a two channel A/D converter designed for most demanding audio applications. It uses state of the art A/D chips in Weiss Engineering’s proven “correlation technique” configuration, which lowers converter imperfections and improves the SNR ratio.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER INTRODUCTION Outputs • AES/EBU on XLR in one or two wire format • S/PDIF on RCA • Firewire (Optional, a kit is available) DSP • POW-R dithering to 16 bits, settable to three different algorithms according to the POW-R standard • SNR enhancement • Level bar graph meter • Two segment compressor / peak limiter • Double-precision 40bit floating-point processing Daniel Weiss Engineering Ltd., Florastr.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER OPERATION OPERATION ADC2 Block Diagram Fig. 1 ADC2 Block Diagram Schematic 1 Input Control Panel compressor / limiter links the sidechains of the two channels. Typical applications for “ganged” mode are This section describes how to use the input control panel (see Fig. 2). • stereo (left/right) recordings with two microphones • stereo insert limiting (during mixdown or mastering). Fig.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER OPERATION Pressing the “digtial in” key activates the digital AES/EBU XLR input, the key lights red if active. As soon as a valid signal is present, the sampling rate is displayed with the sampling rate keys (see Fig. 6). The level bargraph is switched between input and output in the same manner as the peak hold. Thus, if the “input gain” key is lit, the bargraph displays the input peak meter.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER OPERATION Threshold If “threshold” is lit, the rotary knobs control the threshold of the compressor section. The value is shown in the numeric display. If “peak hold” is active, the output peak value is displayed. 0.0 The ADC2 has a two-segment dynamics compressor. The threshold can only be adjusted for the compressor section, which has a fixed ratio of 2:1. -6.0 The limiter has a fixed ratio of ∞:1 with a fixed threshold of 0.0 dBFS.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER POW-r Dither Sync and Dither Control Panel Fig. 6 ADC2 Sync and Dither Control Panel Sampling Frequency If the analogue inputs are selected (“digital in” is not lit), the A/D sampling frequency can be set in the sync source block: Sampling Frequency OPERATION 44.1 / 48 kHz key fs x 2 / fs x 4 key 44.1 kHz 44.1 kHz none 48.0 kHz 48 kHz none 88.2 kHz 44.1 kHz sf x 2 96.0 kHz 48 kHz sf x 2 176.4 kHz 44.1 kHz sf x 4 192.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER Why dither? If the 24bit digital signal is not dithered when recording to 16bit media (e.g. DAT, CD-R etc), it is truncated instead, which leads to quantization distortion (similar to clipping distortion). Fig. 7 shows a 24bit sine wave at –85dBFS truncated to 16bit. Fig. 7 1kHz Sine wave truncated to 16bit OPERATION To view the frequency characteristics of the three POW-r algorithms, refer to POW-R Noise Spectrum on p. 15.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER OPERATION AES OUT DUAL WIRE Dip Switches AES OUT 2 WIRE DITHER MODE WSYNC TERM. AES IN TERM. If this switch is in the up position, the ADC2 outputs a dual-wire signal. Refer to Table 2 and Table 3 to look up exact output configurations depending on this dip switch. DO1 (XLR 1) DO2 (XLR 2) DO3 (RCA) 44.1 kHz 44.1 kHz single wire 44.1kHz single wire 44.1 kHz single wire Fig.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER DITHER MODE This switch determines how dither is applied to XLR and RCA outputs. Refer to chapter POW-r Dither on p. 7 for further information. WSYNC TERM. If the “WORDSYNC in” is not connected to another device (via a T-connector), this dip switch must be in the down position, in which case the signal is properly terminated. If another unit is connected to the “WORDSYNC in”, this dip switch must be in the up position.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER TECHNICAL DATA TECHNICAL DATA Analogue Line Inputs 2 channels, symmetrical, not earth free, on two XLR female connectors, pin 2 hot. Input Impedance > 5kOhm Analogue Microphone Inputs 2 channels, symmetrical, not earth free, on two XLR female connectors, pin 2 hot. Input Impedance > 5kOhm 48V phantom power switchable AES/EBU Input Input fs range: 44.1kHz 48.0kHz 88.2kHz 96.0kHz 176.4kHz 192.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER TECHNICAL DATA S/PDIF Output Output fs range: 44.1kHz 48.0kHz 88.2kHz 96.0kHz 176.4kHz 192.0kHz Maximum Output Wordlength: Channel Status Data: Connector: Impedance: 24 Bits Professional format RCA female 75 Ohm WORDSYNC I/O Input Connector: Input Impedance: Input Level: BNC female 75 Ohm TTL Output Connector: Output Impedance: Output Level: BNC female 4.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER TECHNICAL DATA Low cut frequency response: 1st order highpass, 3dB point at 40Hz Frequency Response: @ fs = 44.1kHz: 20Hz ... > 20kHz +- 0.3dB @ fs = 48.0kHz: 20Hz ... > 20kHz +- 0.3dB @ fs = 88.2kHz: 20Hz ... > 30kHz +- 0.3dB @ fs = 96.0kHz: 20Hz ... > 30kHz +- 0.3dB @ fs = 176.4kHz: 20Hz ... > 40kHz +- 0.3dB @ fs = 192.0kHz: 20Hz ... > 40kHz +- 0.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER TECHNICAL DATA Parameter Tables Analogue Gain Line Input [dB]: -26.0, -25.0, -24.0, -23.0, etc. in 1dB steps to +16.0 (example: with a gain setting of -26.0, a +26dBu input signal generates a 0dBFS output) Analogue Gain Mic Input [dB]: -6.0, -5.0, -4.0, etc. in 1 dB steps to +54.0 (example: with a gain setting of -6.0, a +6dBu input signal generates a 0dBFS output) Digital Output Gain [dB]: -100.0 , -92.0 , -89.0 , -86.0 , -83.0 , -80.
OPERATING INSTRUCTIONS FOR GAMBIT ADC2 24Bit / 192kHz A/D CONVERTER TECHNICAL DATA POW-R Noise Spectrum Fig. 10 shows the noise spectrum of the three POW-R algorithms at 44.1 and 88.2 kHz. Fig. 10 Output spectrum with 80dBFS / 1kHz sine wave, dithered to 16 Bits, using the three POW-R algorithms at 44.1kHz and 88.2kHz respectively Daniel Weiss Engineering Ltd., Florastr. 42, CH-8610 Uster +41 1 940 20 06 +41 1 940 22 14 http://www.weiss. ch weiss@weiss.
