2. digital
  3. 181426-149317

USB yet again

For a few years I have had an Intona Isolator with Oyaide Continental 5S upstream and Intona Reference downstream connecting Streamer and DAC. Given the Strong benefit of filters on the upstream Ethernet connection I added a LHY Audio USB 3.0 purifier with a Grey Knights power cable. The tightening of the transfer and resultant SQ was remarkable despite having used superior cables before.

While USB remains a compromised transfer format, asynchronous USB is the only protocol synchronising the server’s and dac’s clocks unless both have master clock connections. AES/EBU may have better noise rejection but has imbedded clock signal,SPDif is outdated as well as speed constrained and I2S not standardised. Hopefully the industry comes up with a better solution. It is interesting that there seems to emerge a trend to combine server and dac: one wonders why?

antigrunge2
danager's avatar
danager
959 posts
 

Ted Smith, PS Audio DirectStream DAC inventor uses / used USB on the original DirectStream DAC (there’s a new version now with galvanic isolation). Ted believed that the biggest issue with USB is the noise from the 5V power generated by the source. Unfortunately the DAC requires the 5V to be recognized but an inexpensive work around is available. A powered USB 2.0 hub and a power blocker adapter removes the computer’ 5V allowing the hub provides its own.

My experience is that it improved the sound quite a bit. I2S into the latest version of the DirectStream is probably better but defiantly not what I would call an inexpensive upgrade.

itsjustme
682 posts
 

asynchronous USB is the only protocol synchronising the server’s and dac’s clocks

Confused.

Can you explain how does an asynch protocol synch two clocks?  Hint: it doesn't.

AES/EBU may have better noise rejection but has imbedded clock signal,SPDif is outdated as well as speed constrained

confused again.  AES/EBU is fundamentally SPDIF that is 1) balance and 2) contains optional metadata.  Speed constrained?  Not for the vast majority of formats and oversampling in even remotely common use....

 

 

clearthinker's avatar
clearthinker
1,582 posts
 

Oh dear!    The agonies of going digital.

antigrunge2 OP
1,437 posts
 

@itsjustme

technically speaking it slaves the server’s clock, i.e. data is requested by the dac rather than the server sending it on its own clock.

I stated that SPDif is speed constrained, not AES/EBU.

zappas's avatar
zappas
176 posts
 

+1 for USB

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