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Importance of clocking

There is a lot of talk that external clocks because of the distance to the processor don‘t work. This is the opposite of my experience. While I had used an external Antelope rubidium clock,on my Etherregen and Zodiac Platinum Dac, I have now added a Lhy Audio UIP clocked by the same Antelope Clock to reclock the USB stream emanating from the InnuOS Zenith MkIII. The resultant increase in soundstage depth, attack an decay and overall transparency isn‘t subtle. While there seems to be lots of focus on cables, accurate clocking throughout the chain seems still deemed unnecessary. I don‘t understand InnuOS‘ selling separate reclockers for USB and Ethernet without synchronising Ethernet input, DAC conversion and USB output.

antigrunge2
antigrunge2 OP
1,461 posts
 

@kijanki

 

You are not addressing my point on processor loading. Or who else is cleaning up the mess?

kijanki's avatar
kijanki
4,432 posts
 

@antigrunge2 What processor?  The only one that can affect timing of D/A converter is in the DAC.  It loads samples from the buffer into D/A converter at even time intervals.  It also signals back when buffer is too empty or too full. 

Sending asynchronous data in packets is reducing stress on receiving end allowing receiver to get data in the required or convenient time.

 

antigrunge2 OP
1,461 posts
 

So where is error correction happening if not at the D/A processor?

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kijanki's avatar
kijanki
4,432 posts
 

AFAIK there is no error correction with asynchronous USB.  Frames contain checksum (CRC field), but I’m not sure if computer resends the frame.  In plain USB transfers device on receiving end sends back “negative acknowledge” (NAK) and frame is resent.  

Asynchronous USB is reclocker.  Placing another reclocker in front of reclocker won’t do anything.   Perhaps these devices were initially intended for synchronous or adaptive audio USB.  Asynchronous USB came later.  Another benefit is electrical isolation from noisy computer.  Reducing electrical noise injected into audio device is always good.  If your reclocker is improving sound by doing this then it is worth the money.

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