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Re: Thanks ...

DACs are generally slaved to the transport clock using a PLL to lock on to the clock embedded in the datastream. Simple communications decommutating using a biphase encoded signal. Some DACs do use their own clock which would of course by nature be asynchronous as you say, but they either use a big enough buffer delay to compensate or use a ASRC to change the sample rate to match the clock.

Even a computer to DAC connection using USB is a synchronous type system with PLL circuits locking on to the computer source clock, at least when using normal audio isochronoous (timed) data transfers.

The data coming off the CD is only self-timed in the way that Zeet explained. There's a PLL involved that does the clocking and it's frequency is based on a negative feedback circuit involving the FIFO. The main problem is that there's no real isolation between that datastream coming off the disc with all its edge jitter, some of which can be traced back to the CD mastering clock, and the system clock in the CDP since they share the same circuitry. There could be with careful design to isolate the clock and analog conversion section from the disc reading section, but it just isn't normally done.

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