Mnyb wrote: > If you read archimagos blog , it is some kind of weird gain problem a HT > bypass mode in his preamp and probably some other design issue . >
Its incidence (but not severity) is inherent in high speed USB: Following a link in archimagos blog about the Corning Optical Isolator (which is in its way for real): [URL="http://www.usbmadesimple.co.uk/ums_6.htm"Usb made simple "Frames and Microframes"[/URL] " Frames and Microframes The 1 ms frame rate in full speed / low speed USB, is used for a number of purposes, such as scheduling access to the bus, and as a timing reference for interrupt and isochronous transfers. For high speed, a higher frame rate was deemed appropriate, while still maintaining a relationship with the existing 1 kHz rate. To this end, high speed uses the 'Microframe' which is 125us long (8 Microframes per millisecond). The correspondence with the 1ms frame numbering is maintained in the high speed SOF packets by repeating each frame number in 8 successive Microframes. " > > Having good gain scaling in a system makes a lot difference , to much > gain everywhere is very common . Yes if its 100dB down you wont hear it > I agree, its often less . In most system you never hear -100dB signal > sitting in the listening position with your usual volume even if its the > signal alone unmasked by music In the Blog the actual level was: 18104 A little higher than -100 dB, but not much. This is IME a very implementation-dependent number. You can get good performance here without add-ons if you have the right gear and a clean setup. +-------------------------------------------------------------------+ |Filename: 8kHz_USB2.png | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=18104| +-------------------------------------------------------------------+ ------------------------------------------------------------------------ arnyk's Profile: http://forums.slimdevices.com/member.php?userid=64365 View this thread: http://forums.slimdevices.com/showthread.php?t=103684 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
