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Listed in: DACs
We have this preowned Weiss Engineering DAC202 FireWire 24-bit/192kHz DAC. It is in excellent condition which can be seen in the pictures attached. It comes with the original box/packaging, remote control, UK mains lead and user manual.
Please note the Weiss Engineering DAC202 is not the USB Version
The Weiss DAC202 has not only two FireWire ports, but also AES/EBU, S/PDIF RCA, and TosLink connections. A BNC input and output allow it to lock on to an external clock. There are also ouputs for AES/EBU and RCA S/PDIF digital signals. The narrow front panel has a largish LCD screen and a single knob, which you spin or depress to access and control any of the DAC202's menus and functions. The infrared remote control can be used to access the most frequently used functions: Power, Volume, input (FireWire, XLR, RCA, TosLink), Mute, Phase, and Filter, for the two onboard digital filters (more about those later). I found the dimmable screen very intuitive and easy to use to access every feature of the DAC202, and the remote is simple and elegant in design and feel. Also on the front panel are a ¼" headphone jack, an IR sensor, and a power-status LED. The fit and finish are good; the front panel's beveled edges look quite nice, and the knob had a sturdy yet silky feel. Still, the DAC202's looks favor function over opulence.
The DAC202's power supply uses a toroidal transformer and there are separate voltage regulators for the analog and digital supplies, a total of 11 regulators. The circuit board is laid out for optimal current distribution. The DAC202 uses the premium ESS9018 DAC chip, which allows for two digital filters (here labeled A and B) to be used. According to designer Daniel Weiss, filter A is optimized for an ideal stopband corner frequency, while filter B has a relaxed transition band that gives the optimum transient response. Jitter is suppressed with what Weiss calls a Jitter Elimination Technologies Phase Locked Loop (JET PLL), which uses feedback to lock the local oscillator to the incoming timing reference. In the DAC202, the JET PLL has two loops. One has its corner frequency set low enough to give good jitter attenuation. The corner frequency of the other loop, which regulates the analog oscillator, is set much higher. The DAC202 uses two converters per channel to increase its signal/noise ratio by 3dB, and it can accept data resolutions up to 24-bit/192kHz.
While so many other consumer DACs now connect with computers via USB, the Weiss DAC202 uses FireWire, which is favored in professional audio circles and fundamentally differs from USB in a number of ways. First, FireWire has greater bandwidth than USB and can therefore transfer more data faster. Second, FireWire is a peer-to-peer protocol, which means that every device on a FireWire network is equally capable of talking to every other device. Third, FireWire is always implemented in hardware, with a special controller chip in each device; the communications load it puts on your computer's CPU is much lighter than USB's.
According to Daniel Weiss, FireWire is more reliable than USB because it offers what he calls "isochronous mode, and it lets a device carve out a certain dedicated amount of bandwidth that other devices can't touch. It gets a certain number of time slices each second as its own. The advantages for audio should be obvious: that stream of data can just keep on flowing, and as long as there isn't more bandwidth demand than the wire can handle (not very likely), nothing will interfere with it. With our products, the FireWire connection works in the so-called isochronous mode, which means that a defined bandwidth is reserved for the link and cannot be taken by another device on the bus. To use USBspeak, the transfer is asynchronous; ie, the master clock sits in the D/A converter and the computer is slaved to it."
The DAC202's volume control is an analog/digital hybrid. Via a menu on the LCD screen, four coarse volume steps in the DAC202 are implemented in the analog domain. Once a range is set, controlling the volume, using either the knob or the remote, is done in the digital domain. This lets the user run the digital volume at the top of its range, where its effect on the signal's word length is minimal. Weiss also applies noise-shaped dithering to the 24-bit volume control to maintain maximum transparency.
Weiss Engineering DAC202 FireWire 24-bit/192kHz DAC Specification:
Digital inputs: XLR, RCA, TosLink (optical), two FireWire.
Supported sampling frequencies: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz on any of the inputs, except TosLink
Digital outputs: XLR, RCA, two FireWire
Analog outputs: Balanced on XLR, unbalanced on RCA