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

The NuPrime CDT-8 Pro transport has a high jitter output (190 psec), which was far higher than my 1996 CAL Delta transport (<50 psec). The CDT-8 transport sounded unremarkable—clearly not superior to the Delta transport—when fed to my Theta DSPro Basic 3A R2R 20-bit, 8x oversampling DAC. 

I then aquired a Jay’s Audio CDT2 MK2 transport. Superb top-loader with ultra low jitter. Result when connected to the Theta DAC? Best Redbook CD playback ever from my system. Micro and macro dynamics, imaging, resolution and soundstage extended well beyond the offerings of the other two digital transports when combined with the same DAC. 

My take-home message is that the jitter-encoded signal from the transport likely contributes significantly to how well one can distinguish playback differences in the DAC, as well as whether the full potential of the DAC can be realized.

In my case, the transport made a huge difference. I suspect the same effect is taking place with your system, where a jittery transport over-rides any benefit afforded by the downstream DACs. 

I have heard a lot of good things about the Denafrips Pontus. I don’t know if it has the reclocking hardware of the more expensive Venus or Terminator. 

Folks sell digital data stream reclockers to reduce or remove jitter. Try one for the digital stream output from your NuPrime CDT-8 Pro transport. That might help clarify how well the two DACs perform when compared.

Try shooting a pm to Steve Nugent of Emperical Audio. His member name here is audioengr. 

https://www.empiricalaudio.com

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.

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.

OP: I’m not going to go into depth of the banter between Jason and me other than to say he felt jitter at 120 psec was “low” although he suspected it was nevertheless inaudible. I disagreed with him, holding the position that jitter at any level above 10 psec was audible in terms of absolute SQ.

Steve Nugent and a parade of others agree with my view. The Jay’s Audio transport when inserted into my system confirmed this view for me.