In article , Phil
Allison wrote:
** In fact, CD players using TDA1540 DACs usually had high levels of
supersonic hash at the output - viewed on a scope, this amounted to 20
or 30mV rms whenever a CD was playing. This hash defeated most reviewers
and others attempts to verify the s/n ratio and THD figures claimed by
Philips.

I'd echo with that. I used a '1st generation' Marantz player with the same
Philips 14bit x 4 chipset. I added a Toko analogue low pass filter to its
output. This limited the bandwidth to about 19kHz, but reduced the hash. I
felt it sounded better as a result. Used it happily for about a decade.

The filter was a design that used to be made and sold in quantity for use
in the Yamaha-style FM tuners that had active 19kHz pilot tone nulling. So
could use a wider filter to keep a more uniform response up to about 15kHz
than the filters which had to remove the pilot.

Jim

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