SAA7220 spdif question

[amc184]

Originally Posted by UV101

... Surely the second filter would have no comprehension that the i2s has already passed a filter?

Yes, as far as the data having been altered is concerned. However, it's an oversampling filter, the output I2S bus runs four times as fast as the input one. This will cause problems as the SAA7220 can't run that fast, as well as the relationships between the I2S clocks and the master clock being altered.

[pieter t]

To my ears the SAA7220 can be part of an excellent sounding CD system.
The last couple of days I worked on, and compared, the digital output of my old Rotel RCD955-AX, which is based on Philips chips (SAA7220-TDA1541A), with a more ambitious Kenwood DP-X9010 CD transport (Sony CXD1125 demodulator chip).
After optimizing the quality of the SP/DIF signals in both players (the pulse transformer in the digital output line of the Rotel was removed as it completely destroyed the quality of the signal) and listening to each "transport" the last days I prefer the Rotel/Philips, sounding more fluid and less harsh compared to the Kenwood.
DA converter is the really excellent Metrum Acoustics Octave, a non oversampling type which does not use the well known "audio" chips, and puts out a signal without needing an analog output stage. This converter is quite "hot" at the moment after a review at 6moons, and to my ears it deserves every right to be so; this combo provides me with by far the best and most musical CD playback, and that's with the SAA7220. Sound surpasses everything I heard until now, including Sabre, BB and AD (non) oversampling and or upsampling types.
NOS Mini DAC Octave
My conclusion: it's all in the implementation.

[abraxalito]

Originally Posted by pieter t

This converter is quite "hot" at the moment after a review at 6moons, and to my ears it deserves every right to be so; this combo provides me with by far the best and most musical CD playback, and that's with the SAA7220.

Just worth mentioning here that the SAA7220's filter isn't in circuit in such a set-up, only its error-interpolation and SPDIF modulation functions.