192 from usb/spdif to NOS dac to amp

What does sigma delta mean?

I have always understood that NOS dacs are less effected by jitter than upsampling dacs. Also my Audio Note transport has no jitter reduction at all. Audio Note does not feel that jitter is really a problem with there gear.
Alan

Matt, the difference between traditional converter and
sigma-delta is pretty much the same as the difference between
CD and SACD. Instead of creating many discrete voltage
levels, corresponding to input code, Sigma-Delta creates
bitstream of varying duty cycle that after filtering (taking
average) delivers voltage proportional to duty cycle. SACD
is exactly that but unfiltered yet. There are several
advantages of Sigma Delta the most important is moving
quantization noise to much higher frequencies outside of the
audioband. Quantization noise in normal people language
means simply "steps". Sigma Delta has only one
large step (being one-bit converter) but repeated at very
high frequency. Any residue of the steps has very high
inaudible frequency. For SACD it is 2.8MHz.

Just bought this usb/spdif converter. Hoping that I can learn a few things with it.

Product Description (taken from site)

U12 uses the XMOS professional audio field X-CORE 32BIT / 500MBPS digital signal processing unit, the inside has 8 cores, with powerful multi-core multi-thread processing capability, is being outstanding in industry and provided a USB Audio Class 2.0 digital audio solution. Product Features: • Use XMOS programs to support 32B 384khz asynchronous 2.0 (recommended ASIO output when using USB) • using an independent power supply. Built-in sealing ring cattle, multiple sets of multi-level regulation. About the importance of independent power, I believe we all know. • optimize the design of the audio clock circuit using 0.1PPM precision active crystal to provide a more perfect clock signal to digital audio. Provided for by the two crystals were 44.1 / 88.2 / 176.4 / 352.8Khz and 48/96/192 / 384Khz series rate signal only after the selected clock rate selected work, work another one audio clock stop, put an end to the mutual interference may bring work simultaneously when the two clocks. • A total of four kinds of output: Coaxial (RCA), optical fiber, AES / EBU, IIS (HDMI port) Coaxial fiber AES / EBU output formats IEC60958 and AES3-r2009 standard limits the maximum support 24Bit / 192kHz; IIS can transmit 32B 384K • smart switch, USB has a current interface to boot. Interface with the computer switch and switch machine (computer to be set off USB power failure), or unplug the USB cable directly to the shutdown.