Best clock for 192's? - Page 2

thenoiseflower · 24th July 2007

Quote:

Originally Posted by Jim Williams

BTW, the best clock for Pro Tools is the one on the wall. The one that's telling you that you are wasting too much time on this mix.

Jim Williams
Audio Upgrades

Jim Williams · 24th July 2007

There is a very interesting article in the July 23 issue of Electronic Engineering Times on clock jitter.

EETimes.com

"Resistor keeps lid on jitter" by Gary Giust of Phaselink Corp. He's an authority on jitter minimization.

He shows how a simple 100 ohm resistor at the Xin /REF pin of the VCXO will drop jitter by 40%. The resistor placed between the driving IC and the XO in combination with the internal XO input pin capacitance (Cxin) forms a low pass filter with a cut-off frequency of 1/(2 pi Rs Cxin). The filter slows down the input clock edges at the Xin/REF pin reducing voltage droop and ground bounce on the power supply rail.

Good stuff, let's hope Digidesign reads this.

Jim Williams
Audio Upgrades

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24th July 2007	#32
Jim Williams Voiding warranties Joined: Feb 2004 Location: beautiful Carlsbad, CA Posts: 10,081	There is a very interesting article in the July 23 issue of Electronic Engineering Times on clock jitter. EETimes.com "Resistor keeps lid on jitter" by Gary Giust of Phaselink Corp. He's an authority on jitter minimization. He shows how a simple 100 ohm resistor at the Xin /REF pin of the VCXO will drop jitter by 40%. The resistor placed between the driving IC and the XO in combination with the internal XO input pin capacitance (Cxin) forms a low pass filter with a cut-off frequency of 1/(2 pi Rs Cxin). The filter slows down the input clock edges at the Xin/REF pin reducing voltage droop and ground bounce on the power supply rail. Good stuff, let's hope Digidesign reads this. Jim Williams Audio Upgrades