jkeny wrote: > Seems to me that this is FFT basics 101 - incorrectly interpreting the > "grass" seen on an FFT as the "noisefloor" - in Archimago's graph > -140dB > > Have a read of this document in order to understand > http://www.ni.com/white-paper/4278/en/ > > > What is being shown in the graph is "narrowband noise level in each FFT > bin." not the noise floor although the noise floor can be calculated > from it given some background information. > > As to the Regen - it has a good theoretical explanation from John > Swenson - the increased electrical noise generated within the USB Phy in > handling USB signals with reduced signal integrity. This Regen device > seems to address this issue by moving the electrical noise problem off > the main USB DAC board into a separate USB hub device. The advantage > being that this is USB hub is independently powered & therefore > electrical noise can be treated independent to the USB DAC. It then > generates a new USB signal with presumably better signal integrity which > is meant to be located at the input to the USB DAC. > > This electrical noise spoken of by John Swenson & which this device > addresses is not quite the same as the 8KHz spike seen in ARchimago's > graph which is directly related to 8kHz "packet noise". Archimago's > graph, however, does illustrate how internal chip activity creates > electrical noise which can make it to the output.
Thanks jkeny, a much better explanation than my lame attempt! Rg System information ------------------------ Main: Vortexbox/Squeezelite > USB> Benchmark DAC2 D > LFD LE IV Signature amp > Revel Performa F208 speakers. Home Theatre: Touch (Wired) > Pioneer VSX 919 > Energy Take 5 Classic 5.1, Touch FW 7.8.0-r16754. LMS 7.9.0 - 0.71.20150313git1426153261 on a 1TB Micro Vortexbox Appliance, V 2.3. ------------------------------------------------------------------------ rgro's Profile: http://forums.slimdevices.com/member.php?userid=34348 View this thread: http://forums.slimdevices.com/showthread.php?t=103684 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
