Dear customer, Congratulations on your purchase of the DAC202 D/A Converter and welcome to the family of Weiss equipment owners! The DAC202 is the result of an intensive research and development process. Research was conducted both in analog and digital circuit design, as well as in signal processing algorithm specification.
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Updated manuals and datasheets are available at our website for downloading. Weiss Engineering makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does part of this manual, and specifically disclaims...
(Studer-Revox ) company in Switzerland. His work included the design of a sampling frequency converter and of digital signal processing electronics for digital audio recorders. In 1985, Mr. Weiss founded the company Weiss Engineering From the outset the company concentrated on the design and manufacture of digital audio equipment for mastering studios.
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2004 Introduction of the JASON CD Transport 2007 Introduction of the CASTOR, our High-End Hi-Fi power amplifier 2008 Introduction of the MINERVA Firewire DAC and the VESTA Firewire- AES/EBU interface 2010 Introduction of the DAC202 Firewire DAC, the INT202 Firewire Interface and the ATT202 passive attenuator...
Contents Introduction A Short History of Weiss Engineering 1 Advanced Digital and Analog Audio Concepts Explained 1.1 Jitter Suppression and Clocking ....
Chapter 1 Advanced Digital and Analog Audio Concepts Explained Jitter Suppression and Clocking What is jitter and how does it affect audio quality? In the audio field the term jitter designates a timing uncertainty of digital clock signals. In an analog to digital converter (A/D) the analog signal is sampled (measured) at regular time intervals;...
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(e.g. CD transport) and the D/A converter unit or by the same mechanisms as described above—except for the motors of course. In the case of a stand-alone D/A converter (as the DAC202), one has to take two different jitter contamination paths into account. One is the internal path where internal signals can affect the jitter amount of the sampling clock generator.
mutes) you should hardly hear any difference between different makes of CD transports or between different pressings of the same CD. Also accessories“ like ” disk dampening devices or extremely expensive digital cables will not make any difference in sonic quality. Of course it is always a good idea to have a good quality cable for digital (or analog) audio transmission—but within reason.
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the same filter is required. This is because after the D/A conversion we have a time discrete analog signal, i.e. a signal that looks like steps, having the rate of the sampling frequency. Such a signal contains not only the original audio signal between 20 Hz and 20 kHz but also replicas of the same signal symmetrical around multiples of the sampling frequency.
filter for that purpose. Analog Output Stages The DAC202 employs separate output stages for the main output and the headphone output. Both stages use state of the art operational amplifiers with high slew rate. A topology with a very low output impedance has been chosen.
components but a slightly increased noise floor. This works like magic—the distortion is replaced by a small noise which is much more pleasant. I have given the example of a 24 bit recording, which has to be truncated to 16 bits. Where is the application in High-End Hi-Fi audio? More and more signal processing is implemented in the digital domain.
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16 bit signal is truncated to 8 bits; 8 bits in order to clearly show the effect. Notice how the noise (distortion) is modulated by the music signal. www.weiss-highend.ch/computerplayback/nodither.mp3 This is how a badly implemented digital level control works. . . Fortunately there is a better way to handle the re-quantizing.
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I hope these excursions into the theory and practice of audio engineering has been useful for you. If you would like to dive further into those issues I recommend visiting the website of Mr. Bob Katz, a renowned mastering engineer and a Weiss Engineering customer.
Chapter 2 The DAC202 D/A Converter Features in Alphabetical Order Absolute Phase Switch The absolute phase of the outputs can be inverted for optimizing the sonic impression. Audio Inputs One XLR, one RCA and one Toslink connector for AES/EBU or S/PDIF signals.
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Single Wire mode, i.e. both audio channels are transferred via a single cable. The DAC202 also supports the Dual Wire mode where the two audio channels are transferred via two cables, i.e. left channel is on the XLR connector and the right channel on the RCA connector.
The other brightness level is active when the DAC202 or the remote control are not touched. This allows dimming the LCD when the information on the LCD screen is not required.
Figure 2.3: DAC202 remote control Remote Control The IR remote control allows to control the following parameters: Power on/off Volume up/down Input source (Firewire, XLR, RCA, Toslink) Output mute Absolute phase normal/inverted Upsampling filter type Signal Routing Due to the various possible settings for input source, insert mode, dual/single wire modes and sync source there are quite a few routing paths possible.
For that purpose audio files are supplied with the DAC202. Playing back these files via the player software to be checked allows the DAC202 software to recognize the bit pattern of the files. If the bits of the files are changed during playback e.g.
When power is applied to the DAC202 the blue standby LED is lit. When the DAC202 is switched on, the blue LED is turned off and after a short while the LCD screen comes on.
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Figure 2.5: Options Menu highlighted Figure 2.6: Input mode selection Options Menu as shown in figure 2.5. Pressing the knob again enters the Options Menu (p. 18). Input Mode Rotating the knob instead of pressing it navigates to the input source select as in figure 2.6.
Here is a rundown of all entries in the options menu: Absolute Phase ,,+“ or ,, “. A ,,+“ means the signal is not inverted when passing through the DAC202. A ,, “ means the signal is inverted. Upsample Filter Upsample filter type A or B. Later software versions may allow to select C, D etc.
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WC BNC This selects the BNC connector at the rear of the DAC202 as the synchronization source. If the DAC202 is used in dual wire mode read the instructions for the dual wire mode regarding external synchronization. 1394 bus This slaves the DAC202 clock to the Firewire bus. This setting is only required if more than one DAC202 unit is connected to the same computer for multichannel playback.
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This mode is selected if the DAC202 is used as a preamplifier. If bypassed, the volume knob and the remote control volume work only on the headphone output.
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When playing a particular file make sure the DAC202 shows the same sampling rate as the file played has. If the two rates do not match then there is a sampling rate conversion going on and bit transparency cannot be achieved.
Whenever the sampling rate is changed in the AudioMidi setup or the Weiss Firewire IO window, the iTunes program has to be restarted to gain bit transparency again. For iTunes running on a Mac OS X computer a program like Sonic Studio’s Amarra is highly recommended.
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192 kHz. With all other sampling rates the DAC202 automatically switches to dingle wire mode. Dual wire mode is useful for digital audio equipment connection to the DAC202 where the units only support the high sampling rates (176.4 kHz or 192 kHz) in dual wire mode.
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audiorate (174.6 kHz and 192 kHz) In the following we will discuss the various operating modes. Mode: Firewire input/single wire/no insert The Firewire input is routed to: DAC chip, XLR out, RCA out, APB. The Firewire output (going to the computer for recording) is fed from the source specified as the sync source.
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XLR is the left channel signal going to Firewire and RCA is the right channel signal going to Firewire. Toslink selected as sync source: Not supported. Internal or WC BNC or 1394 bus selected as sync source: The Firewire output is muted. The DAC chip is fed from: XLR input (left channel) and RCA input (right channel).
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Mode: S/PDIF(RCA) input/single wire/no insert The RCA input is routed to: DAC chip, XLR out, RCA out, Firewire out, APB. The Firewire input, XLR input and Toslink input are not routed anywhere. The sync source can be specified as the XLR input, the RCA input, the Toslink input the WC BNC input, the 1394 bus or the internal sync generator.
Mode: S/PDIF(RCA) input/dual wire/insert active This mode is not supported. Software Installation Perform the following installation procedure before connecting the DAC202 to the computer. The necessary files are supplied on the enclosed drivers CD. Windows 1. Do not connect the device.
9. Click Restart. After installing the drivers, connect the DAC202 to the computer and connect the power cord to the DAC202. Switch the DAC202 on. The DAC202 should now be recognized automatically. In Windows tell the installation window that you do not want to check the Microsoft website for drivers and then let the drivers be installed automatically.
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(XLR, RCA, TOS ) the sampling rate indicated reflects the one fed from the external device. Sync Source The clock to which the DAC202 should sync to. Usually this is the DAC202’s internal clock generator.
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Operation Mode Determines the stability of the system. Try other modes if there are clicks in the music. Note that when using the XLR, RCA or TOS inputs there is no need to hook up a computer to the DAC202. Global Settings/Info Information about the driver version.
Chapter 3 DAC202 Technical Data Digital Inputs (1) XLR connector, (1) RCA connector, (1) Toslink connector (optical), (2) Firewire connectors. All inputs accept professional or consumer standard, i.e. ac- cept AES/EBU or S/PDIF signals. Supported sampling frequencies are 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz or 192 kHz on any of the inputs, except Toslink which handles 96 kHz...
8.15 V setting: 500 Ω or higher 4.15 V setting: 300 Ω or higher 2.12 V setting: 150 Ω or higher 1.06 V setting: 70 Ω or higher RCA Output 4.08 V +14.42 dBu with a 0 dBFS sinewave input 2.08 V +8.55 dBu with a 0 dBFS sinewave input...
Power Mains voltage: 100–120 V or 200–240 V Fuse rating: 500 mA slow blow at 100–120 V, 250 mA slow blow at 200–240 V Power consumption: 15 VA max. Power consumption in standby: 1 VA max. Measurements Main Output The measurements below have been taken at the following conditions (unless noted otherwise): 1 kHz measurement frequency, maximum selectable output level, 192 kHz sampling frequency ( ), 22 kHz measurement bandwidth, un-...
At 0 dBFS input level, maximum output level, 300 Ω load, 1 kHz, all components at less than 120 dB At 0 dBFS input level, maximum output level, 100 kΩ load, 4 kHz, all components at less than 120 dB At 0 dBFS input level, maximum output level, 600 Ω...
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