Please Help!! looking to get into computer audio.

Erik - Care to comment on the specifics of the reclocking that is going on in the Bryston BDA-1, the DAC in question. I think you are mixing reclocking with upsampling. The BDA-1 reclocks then upsamples. Two different operations.

The jitter can never be better than the clock in the DAC. You somehow think that the timing is better when applied in async USB mode than when implemented internally in the DAC by reclocking. That is just not true.

Please, address the specifics of the reclocking that is going on with the BDA-1. Are you really saying that if the BDA-1 used aysnc USB then the jitter would be lower than using its internal clock to reclock the data?

And, reclocking is bit perfect. It simply takes the data (2 16 bit data points for each sample) and sends that sample on with the timing of the internal clock.

Your discussion of Schiit filters is an entirely different topic than reclocking.

" The worse the input signal (i.e. more jittery) the worse the output signal " Clearly you do not understand the idea of reclocking of signal as is going on in the BDA-1.

Honestly, I think you are throwing around a lot of terms without really understanding the process that the BDA-1 is using, especially the concept of reclocking.

I kind of hate JRiver, and only moderately despise MediaMonkey.  Something about UI designers who are into music.....they are very odd fellows indeed I think. :) 

So, no JRiver clones for me. I'll have to stick with Logitech Media Server and various tagging/retagging tools I could find.

Best,

Erik

Without knowing the actual implementation, they could use a large-ish buffer and then upsample, but these issues have the same limitations as ASRC. The re-clocker has to constantly try to guess the long term stability of the original source clock AND the buffer has to be big enough to handle the difference between the source clock and the DAC clock.

This is why ASRC is actually pretty easy to implement.  You just say F* it to the original clock completely and really only need a very small buffer. 

My guess, is that they are just doing ASRC, like everyone else these days. 

Again, the best solution among the now 3 different types of implementations is Asynch-USB. 

Try this thought experiment.  Let's say your source is feeding out samples every 1/44,110 of a second instead of 1/44,100 of a second. The only one of the three methods that is immune to this problem entirely is Asynch-USB. The source clock has nothing to do with the frequency of data fed to the DAC (within reason, if the PC is running Windows and it's in the middle of an update, chances are it's all going to hell). 

Parasound's CD player, and some digital players have implemented memory-only players. They read the entire file into memory at once, completely doing away with issues of source jitter. There's no evidence it's better than Asynch-USB though. 

PS Audio has a useful article on this too somewhere, of course it's all pro-PS Audio's dac or something. :) 

Best,

Erik 

Erik - You obviously have a pretty low opinion of Bryston engineering. They understand these timing issue very well. You seem to think they just kind of hacked this together. Guess what - I think they understand buffering issues. A sync usb is only very slightly off in timing.  I do not know for sure, but I bet they are not using a 10 byte buffer.

You act like the usb input on the BDA-1 is total crap, with just awful jitter. Well, I think Byrson engineering is better than that. They understand buffer and timing issue.

You throw around ASRC like it is some sort of technology. Well, it is not a specific implementation and how Byrston implemented its reclocking should not be jumbled with all other ASRC techniques.

Somehow you want to make this into some big discussion about all timing issues in PC audio. The issue I brought up is that the reclocking in the BDA-1 makes it much more immune to jitter than a typical sync usb interface. You seem to not believe that. You seem to think that the reclocking the BDA-1 implements is just as bad as sync usb. Well, I simple do not believe that, Bryston does not think so, and Stereophile does not believe that.

Give it a rest. I agree that async usb is better than sync usb. But, reclocking is implemented for a reason, whether it is in the BDA-1, the W4S unit you referenced, the Empirical Audio reclockers, etc. And, sure, I would rather have an async usb DAC rather than an async one. But the BDA-1 is a fine DAC, with pretty low jitter because of its reclocking.