I read a few threads via gmane, and now understand the regulator hierarchy a bit better. ext DC -> Boost Converter (display) -> maybe another stage -> Low Dropout (LDO) -> Analog. There seems to be no weight, based on this cascade of regulation, to the argument that an external linear ought to be better than an external switcher w.r.t. actual power supply performance (ignoring RFI issues). As you stated in some systems this added RFI from plastic encased switcher may couple on to low voltage high gain elements and manifest in a negative way. I guess the ARC gear is immune to such environmental noise, and as such this may be why I can not detect any difference.
I would like to repeat the experiment with an external DAC. In this case it may be that the DAC I use will be affected by the increased RF noise, and that the linear simply removes this... I have no fundamental problem with switchers! I have come to like the LT1766, as a trusty core in a smps for use in small embedded systems...for a low noise analog supply for a CMOS image sensor, I cascade an LT 3021 LDO, with inline filters. Works like a charm. In the SB3 the voltage ripple going to the LDO is a function of the regultor before it; in this case the one used as a basis for the display, NOT the external supply. The LDO has an input voltage ripple rejection curve that usually gets worse as the frequency increases. Again this is all based on the regulator design in front of this. The ripple that exists on the external supply line is likely to be so suppressed (rejected) by the time it arrive at the LDO, it would be hard to measure wit good instruments. Later dudes. -- dpac996 ------------------------------------------------------------------------ dpac996's Profile: http://forums.slimdevices.com/member.php?userid=9407 View this thread: http://forums.slimdevices.com/showthread.php?t=31758 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
