An important note about the USB input
The USB input on the MOON i3.3's optional DAC accepts a digital audio signal of up to 16-bits/48kHz. This
is the native specification of the USB input. However, if you require a higher sampling rate, there are ways to achieve
this with the i3.3.
Rather than including a USB input for sampling rates exceeeding 48kHz, we opted to provide the best possible
power supply, D/A converter and analog stage in the MOON i3.3 at this price level. Also, keep in mind
that USB wasn’t originally intended for use with hi-resolution audio; there are latency issues which compromise
sound quality (i.e. jitter and phase errors, etc.). These could be minimized through dedicated costly circuitry,
but this would significantly drive up the cost of the i3.3 without improving the sonic performance on any
of the other inputs.
If you intend to use the MOON i3.3’s USB input, it’s very likely that your computer is a data source for music.
Today most computers with a built-in sound card will have either an S/PDIF (RCA connector) or Toslink
(optical connector) digital audio output, thus eliminating the need for a USB input on the i3.3.
Furthermore, if you’re committed to getting the most out of the music stored on your computer, then in all
likelihood you have installed an after-market soundcard in your computer. Virtually all of these soundcards
have at least one S/PDIF, Optical or AES/EBU (XLR connector) digital output. At this point, USB connectivity
becomes irrelevant. The USB input is there for convenience as opposed to performance.
In the event that you wish to use your computer’s USB connection with files greater than 48kHz, there are
several relatively inexpensive after-market products; compact one-box USB-to-S/PDIF interfaces that will
work with USB datastreams up to 24-bit, all the way up to 192kHz.
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 "MOON i3.3 Inside View - Click to enlarge")
 "MOON i3.3 Rear View - Click to enlarge")
