Clocking

High resolution multichannel digital output modules for OPPO BDP-93.
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ackcheng
Posts: 4
Joined: Sun Jan 08, 2012 2:03 pm

Clocking

Post by ackcheng »

Hi,

I'm interested in this product. I noticed that it is using FIFO buffer so the output will be highly dependent on the clock on board. Can I ask you what clock are you using there? Is it easy to replace to a more lower jitter clock by myself?

Yours

Ackcheng
AP
Posts: 366
Joined: Wed Jan 04, 2012 8:34 pm

Re: Clocking

Post by AP »

Hello Ackcheng,
Correct, audio data is clocked from the FIFO buffer by a tunable on-board oscillator in order to strip data from the dirty clock in the player. The oscillator is custom made voltage controlled low jitter type - VCXO. It has pull range +-150ppm and adjustments are controlled by an adaptive algorithm that monitors the utilization of the FIFO and sets the on-board oscillator accordingly. As a result, delays between individual adjustment steps are very long (in order of seconds) and the new clock is very clean. There are two oscillators, one for each frequency base (512x 44.1 and 48 kHz). Only one is running in a time, the other one is powered down.
From the technical point of view it is naturally possible to replace the oscillator with one of similar specs, but it is not that easy and the benefit is rather questionable.

Regards,
Pavel
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