16.9344MHz?

It's 384 * Fs, where Fs is the standard CD sample rate of 44.1kHz.

Audio DACs typically use 256, 384 or 512 * Fs.

Best regards, Spehro Pefhany

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OK, thanks. I understand 256(8 bits) and 512(9 bits), but why 384(8.5 bits?)

"The Journey is the reward"

eff.com

I guess it is padding: 16 Bit (256 and 512) or 24 bit (384).

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

Typical oversampling factor in audio delta sigma DAC/ADC is x128. So the master clock is usually N x 128, where N could be selected as

1,2,3,4,6,8. The serial word length is 2 channels x(16,24,32) bits. It is convenient to divide the serial clock from master clock, that's why ratios like 256/384/512/768.

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

Vladimir Vassilevsky expounded in news:68udneTdhKYejGTRnZ2dnUVZ snipped-for-privacy@giganews.com:

As I recall, more than 16-bits/sample are written to the media. There is some kind of bit stuffing algorithm used, which IIRC adds two bits per sample. But my faded memory of "Lenk's Laser Handbook" may contain some parity errors now.

Warren

(For early versions) Quite a bit more, but they are part of the encoding layers, not usable as part of the audio data stream. At the lowest level each octet is encoded into 14 bits (EightFourteenModulation) and three more merging bits are added to guarantee the patterns meet bit transition density rules. At one level up Reed-Solomon cross interleave error correction is employed. The data redundancy from audio bitstream to disc bitstream is over 200% (added bits). (Later versions[e.g. SACD]) have found ways to use more of the bits = while remaining compatible.

With SACD they don't even both recording regular waveform voltages (i.e., PCM codes): Since most all CD players went to sigma-delta DACs for cost reasons anyway, they figured, hey, why not just record the (highly oversampled) 0/1 bitstream such a DAC would produce internally anyway, and call it good?

So they did.

Interesingly, there's no way to produce (or, hence, copy) an SACD at home: There's digital watermarking added to the initial lead-in section of an SACD in the form of slight (but deliberate/well-defined) elongation/constriction of the pits, and Sony has successfully kept the algorithm to do this a secret as well as maintaining very tight controls on the recorders in the first place.

While SACD has always been a very nichey market (there are numerous surveys out there indicating few if any people can actually tell the difference between a well-mastered CD and an SACD), at the physical layer SACD is a very close kissing cousin to the DVD format... so its development actually proved quite beneficial.

You probably know all this, but I learned it quite recently and find it rather intriguing.

---Joel