DigitalFreak
镇老鹰
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Hi guys, hey Brooko, looks like our findings for the most part are in agreement.
Originally Posted by Brooko /img/forum/go_quote.gif
SO WHAT IS THE UDAC-3?
The uDac-3 is an extremely small (a little larger than a zippo lighter) high resolution USB powered DAC ...
TECHNICAL SPECIFICATIONS
The table below lists most of the relevant specifications.
Input :
USB 1.1, 2.0 compatible
Native Bit Rate :
32, 44.1, 48, 88.2, 96 kHz, 24-bit
Output (line out) :
Analog RCA output = 2Vrms
Dynamic Range :
90 dB
S/N Ratio :
98 dB
THD+N :
0.05%
Digital Output :
Coaxial RCA 75-Ohm
Headphone Output :
80 mW x 2 @ 16-Ohm
Power :
USB Bus Powered, 80 mA/5V
Dimensions :
68 x 38 x 21 mm
If the line out is really 2 Vrms from a 5V USB-powered device in such a small footprint, it would be quite impressive. A pure sine wave with 2V rms has a peak to peak amplitude of 5.66 V, which certainly exceeds the USB standard's allowance for 5V +/- 0.25V for complying devices. I have to admit that I'm a bit skeptical that the device can actually achieve the 2Vrms that's specified on the website; rather, I expect that the output is 4V peak to peak (or 1.41 Vrms).
If Brooko or wolfgang could chime in regarding the output levels of the analog out; specifically, if the little guy can really muster outputs beyond the limits of the input voltage. I'd be very interested in how NuForce achieved high quality boosted voltage rails---I have some small form-factor projects that would benefit from voltage rails > +/- 2.5V! Certainly, it's a specification that would set the udac3 ahead of the other usb-powered DACs that I'm currently aware of.
Cheers
Thanks.....do you know if the RCA analog output is variable with the ability to plug directly into powered speakers?
Also, can this unit be "tricked" into working with iPad/CCK with a powered USB hub?
Great review and Interesting piece of kit. Do you know what DAC chip is inside?
It uses an ESS ES9023.
Also, while the SA9027 is Async capable, it does not appear they are using it in Async mode, just plane adaptive mode (I have not seen a picture
of the bottom of the digital board though...maybe they are hiding the clocks under there..?).
It uses an ESS ES9023.
Also, while the SA9027 is Async capable, it does not appear they are using it in Async mode, just plane adaptive mode (I have not seen a picture
of the bottom of the digital board though...maybe they are hiding the clocks under there..?).
Thanks Avro. well that explains the compact setup, the ESS9023 has an integrated opamp. Reasonable choice for good sound and size. Clock? ES9023 uses i2s as input. The master clock probably is provided by an oscillator under the board. Dont know mayve there is apossibility to get a signal from the usb-i2s chip (xmos?).