A comparison between two DACs, one R-2R, the other ES 9038-based.

A question for celander:
Where can I find the jitter rate of 190 psec that you quoted for the Nuprime CDT-8?
Thanks....

I thought this was first posted in a discussion of the CDT-8 over on AudioCircle, but a quick google search doesn't bring it up.

OP: The CEO of NuPrime (Jason Lim) provided that to me in an email. BTW, I just reviewed that email: it’s 120 psec, not 190 psec. We’ve had a rather spirited back and forth via email about the jitter number and the meaning of their “ultra-low jitter” and “extremely low jitter” language of their marketing materials.

To me, those language snippets mean different values to different folks. For the NuPrime folks, it’s 120 spec. For me, it means <5-10 psec.

The jitter value is measured at their output clock circuit. I have no idea what the jitter output is at the end for a 4 ft. coax digital cable.

Thank you for retrieving that datum, celander. Helpful.

• Did you inadvertently reverse the "greater than" symbol in your second to last sentence, since 120 is larger than 5-10?
• I suppose that Mr Lim would argue that any good DAC [perhaps his DAC-9 or DAC-10?] has on-board jitter reduction that substantially improves upon 120 psec from the transport output. Of course, that is no argument in favour of his specs vs those of transports with lower jitter output.
• I do note, re my OP comparison, that both the Pontus and the Sonica do have substantial jitter reduction capabilities. I suppose that these days any good DAC does.

Best wishes......   

OP: I don’t believe I inverted any symbols. NuPrime thinks “ultra or extremely low jitter” means 120 psec. My interpretation of “ultra or extremely low jitter” is less than (<) 5-10 psec. That’s a big difference in jitter levels that affects SQ. Ask Steve Nugent (audioengr). I returned the transport to NuPrime after audition in my system, as it didn’t improve upon the SQ of my CAL Delta transport, which has less than 50 psec of jitter in the digital output stream. 

Whatever is in Jason’s mind of DAC compensating input jitter reclocking circuits is not relevant to marketing a stand alone transport. If he thought it didn’t matter, then why use marketing language regarding the transport’s jitter qualities? He’s trying to sell a given transport. If he wanted to, he could have pointed out any residual jitter could be reclocked by a suitable DAC having an input jitter reclocking circuit. His marketing language doesn’t point that out, however, for obvious reasons (red flags as to the transport having high jitter output). It’s possible that jitter is lowest via his transport I2S bus. But that is not really clear from his marketing materials, and his report of jitter values at the clock output circuit pretty much dictates jitter output for all digital outputs regardless of formats.

I’m not here to argue about a particular DAC’s input receiver having special associated reclocking circuitry. I merely pointed out that the Pontus DAC lacks the front end digital signal processing of Denafrips Venus and Terminator DAC’s. And that is why one pays a lot more for the top tiers of the Denafrips DAC line.