Hello. THis is a really in-depth technical question. Proabably one of the original Slim designers would have to asnwer it.
I've got my DAC going, and it uses the input Fs encoding in the input data stream to figure out what the output word clock F should be. If the Transporter is running off its internal clock, I see that the DAC is interpreting that correctly and tells me the input word rate. However, I designed my DAC with an output word clock so I could have the Transporter slave off the DAC's word clock. Here's the issue. When the Transporter is set to use its word clock, it appears that the Fs encoding is not coming from the source material like it should be. It looks like the Transporter is changing its mind about what the Fs value should be..... giving first one encoding value, then another, then another, etc. I don't have a logic analyzer in there so I cant see what these encoding values are or how often they're changing. This behaviour is ONLY changing when there is a speed change associated with the two tracks. The upshot of the above is - when there is a speed change from one track to another, the DAC clock selection is oscillating, because the transporter keeps changing the darned Fs on it, the DAC reacts immediately to the change, giving a new clock speed, then it all goes round again. Again I can't really prove what is going on exactly because I haven't a LA at home :-(. Also - my DAC has the ability to manually generate the output word clock. When there is a conflict between the music file and the input word clock, the Transporter uses the word clock correctly. THat is, I can make it sound like the old tape decks that you could change the tape speed. I'm now going to see if the Fs is not correct when this happens. I think the Transporter MUST use the Fs encoding from source material, and ignore what the speed of the word clock is. Is there anyone at Logitech that can tell me what the Transporter is doing? That is, that Fs in the SPDIF output stream is a function of the word clock or not? I content it shouldn't be. If it is, that explains the oscillating behaviour when the Transporter is using its word clock input. -- wayne325 ------------------------------------------------------------------------ wayne325's Profile: http://forums.slimdevices.com/member.php?userid=29916 View this thread: http://forums.slimdevices.com/showthread.php?t=62747 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
