Home Hi-Rez Highway

New high resolution SACD releases, players and technology.

  Register / Login

[ Follow Ups ] Thread: [ Display  All  Email ] [ Hi-Rez Highway ]
[ Alert Moderator ]

Re: There is no "bit clock" coming out of the VRDS Neo

<< Esoteric features ASIC which takes care of upsampling, clocking and other things. It has two clocks (44.1x and 48x) next to it which are also 1-2 inches away from the DACs. This ASIC also provides reference for the DSP master clocks. >>

Alex, I have a UX-1 sitting in my office. This has 4 x PCM1704 DAC chips. The bit clock (critical for low jitter on this DAC chip) is fed from an NPC SM5847 digital filter chip. Right off the bat I can tell you that this is NOT the best way to do things if you are trying to get the best sound quality.

Without taking the time to trace the circuit step-by-step, it appears that the clock signals for the digital filter come from a Xilinx CPLD (complex programmable logic device -- not an ASIC). This in turn appears to receive its clock signal from a coaxial cable that comes from another PCB. Finally, it appears that the master clock on this PCB is a 27 MHz crystal that feeds a Rohm BU2288 PLL chip that generates the audio clocks. Again, this is NOT the way to do things if you are trying to get the best sound quality.

Like I said, the clock path is lengthy and convoluted.

<< So the master clocks clocking the DACs in the Esoteric are not worse than what you have in your player. >>

Actually they are. Besides the physical analysis given above, Stereophile measured nearly twice the jitter on the Esoteric as the Ayre.

This post is made possible by the generous support of people like you and our sponsors:
  Sonic Craft  

Follow Ups Full Thread
Follow Ups
You can not post to an archived thread.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]