Hi,
does the clock frequency have to be the weird 11.2896 MHz ?
Why is it the same for os and non os ?
Does the quality of the clock depend from the cristal quality ?
Bernhard
does the clock frequency have to be the weird 11.2896 MHz ?
Why is it the same for os and non os ?
Does the quality of the clock depend from the cristal quality ?
Bernhard
BCK:
non os (output 7210/7310)
44.1 kHz samplefreq * 32 bits/sample * 2 left/right = 2.8224 MHz.
4 x os: (output 7220)
4 * 44.1 *1000 * 16 (!) * 2 = 5.6448 MHz.
The 7220 needs the double freq for some reason (probably to control the in/out latches it needs more flanks), so thats
11.2896.
non os (output 7210/7310)
44.1 kHz samplefreq * 32 bits/sample * 2 left/right = 2.8224 MHz.
4 x os: (output 7220)
4 * 44.1 *1000 * 16 (!) * 2 = 5.6448 MHz.
The 7220 needs the double freq for some reason (probably to control the in/out latches it needs more flanks), so thats
11.2896.
Philips uses 256 * Fs, or 11.2896 MHz.
Yeah, the oscillator is in the filter, which is a bad idea form the jitter point of view. But you either feed it 2.8224 or 11.2896 MHz.......regardless of where the actual oscillator is.
The crystal is not as important as the supply feeding the oscillator circuit, and the oscillator itself. Once you have all those porblems addressed, you can start looking into better crystals...which will be expensive and diminishing returns.
Jocko
Yeah, the oscillator is in the filter, which is a bad idea form the jitter point of view. But you either feed it 2.8224 or 11.2896 MHz.......regardless of where the actual oscillator is.
The crystal is not as important as the supply feeding the oscillator circuit, and the oscillator itself. Once you have all those porblems addressed, you can start looking into better crystals...which will be expensive and diminishing returns.
Jocko
Yes.
Digital filters/DACs/SPDIF RXs/etc. work on:
192 * Fs
256 * Fs
384 * Fs
512 * Fs
The middle two bring the most common.
Now..........if you have a BB DF1704, and feed it 384 * Fs, it outputs 192 * Fs. But (o/s) CDPs use those two frequencies.
SACD......DVD...etc.......don't even ask. It is not so simple.
So.........be glad CDPs use only 2 "weird" frequencies.
Jocko
Digital filters/DACs/SPDIF RXs/etc. work on:
192 * Fs
256 * Fs
384 * Fs
512 * Fs
The middle two bring the most common.
Now..........if you have a BB DF1704, and feed it 384 * Fs, it outputs 192 * Fs. But (o/s) CDPs use those two frequencies.
SACD......DVD...etc.......don't even ask. It is not so simple.
So.........be glad CDPs use only 2 "weird" frequencies.
Jocko
guido said:
Yes, I2S use to be 32 bits per channel in each word. Then it can acommodates data with more than 16 bits resolution. I think that this is standard but I'm not really sure.
Roberto
RR said:
No I2S can be any wordlenght!
7210: 32 (16 bits not used)
7220: 16
cd-pro output: 24 (think i read that somewhere).
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