Pat Farrell;243944 Wrote: > seanadams wrote: > > The crystals were chosen to do 44.1, 96, and fractions thereof. Why > not > > put a crystal fast enough for 88.2 in there? Because when you are > trying > > to minimize jitter, EMI, noise etc, you use the slowest possible > clock > > rates, the least possible amount of clock dividing, etc. > > Interesting. Since I know nothing about crystals, and can barely do > multiplication and division, what's the common frequency that works for > > 44.1 and 96 but doesn't work for 88.2?
There isn't one, practically speaking, so there are two crystals: 11.2896 and 24.5760 MHz. Divide by 256 or 512. > isn't 88.2 just twice whatever > works for 44.1? Yes... but before someone suggests "modding" a 22.5792 crystal in its place, this will not work because the system won't know that its twice and fast, much less be able to deal with it, and will just play at 2x. I need to refresh my memory on some details of the hardware lest I put my foot in my mouth, but there may be ways to run higher sample rates at lower clock multiples (ie 128x). If possible it would be a significant reworking of both the programmable logic and the firmware to do this, so I can't promise anything. -- seanadams ------------------------------------------------------------------------ seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=40315 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
