JohnSwenson
Senior Member
	  	
Join Date: Jun 2006
Posts: 113


In the touch the S/PDIF stream is reclocked by a low jitter flop fed 
directly from the main clocks. The SB3 has the stream coming directly 
from the FPGA. That almost certainly gives lower jitter on the touch output.

The SB3 has some EMI suppression devices on the output which messed up 
the impedance characteristics significantly increasing reflections on 
the cable, thus increasing jitter in the receiver of the DAC. The touch 
does not have these.

Both the touch and the SB3 have a separate "connector board" which is 
only a two layer board. Maintaining proper impedance of the traces when 
going from the multilayer main board to the double sided board was not 
done very well on the SB3, it seems to have been done much better on the 
touch.

So all in all the touch has a very well done S/PDIF output with a fair 
amount of effort put into preserving low jitter on its way to the DAC. 
Its not using expensive parts or any special "magic bullet", just honest 
good design and implementation with attention to the details.

John S.

eMJei wrote:
> interento radija, kaip ir bet ka kita ka squeezbox daro, turbut galima 
> pasiusti i isorini DAC?