Which transport with my Jay's Audio DAC?

OP: he’s asking about your DAC. 

Well, I bought the Jay’s Audio CDT2 MK2 transport without having auditioned it. It’s a great addition, replacing my trusty CAL Delta CD transport. 

I think that the Jay’s Audio companion DAC is matched to the form factor of their transports. I would imagine you can’t go wrong with it. 

I decided to go with an Exogal Comet Plus to replace my Theta DSPro Basic IIIa DAC. 

I’ve auditioned both the NuPrime CDT-8 Pro and Jay’s Audio CDT2 MK2 transports over at least one month periods. The Jay’s Audio transport is far better than the NuPrime transport. 

OP: the Theta DAC is a 25-year old Redbook DAC. It only locks onto 44.1k and 48k signals.

Both were fed into my Theta Digital DSPro Basic IIIa DAC as conventional Redbook signal inputs (16-bit/44.1k). I posted my results on Teajay’s thread about the Jay’s Audio transport.

https://forum.audiogon.com/discussions/if-you-still-spin-cd-s-their-is-a-reference-level-transport-f...

TBH, the NuPrime was not any better than my 20-year old CAL Delta transport on Redbook signal processing via the Theta DAC. The Theta DAC has chameleon-like character, revealing the strengths and weaknesses of the upstream transport. 

OP wrote in his OP: “The question, then, is which combination is likely to be the better: 1. The Nuprime transport and the Jay's Audio DAC or 2. The Jay's Audio transport and the Jay's Audio DAC? Does the presumed superiority of the Jay's Audio transport more than compensate for the OS-ing capacity of the Nuprime DAC?”

I provided my experience with 3 transports feeding a Theta DAC. The Jay’s Audio CDT2 MK2 was clearly superior in every respect to the CAL Delta and the NuPrime CDT-8 Pro. The NuPrime transport has twice or three times the output clock jitter as the CAL Delta transport. So I’m not surprised the NuPrime transport didn’t do as well as the CAL transport. And yes, I’m talking about the transports’ Redbook signal processing. If a transport can’t excel at Redbook signal processing, then what hope does it have at processing higher sample rates? GIGO. 

OP wrote in OP: “However, it does not provide PCM oversampling or DSD; and I think that the Jay's DAC cannot oversample a signal on its own. [Can any DAC?]”

Plenty of DAC’s can perform both OS and NOS. In fact, the Jay’s Audio DAC can do both. 

https://www.jays-audio.com/product-page/jay-s-audio-signature-dac-2

OP: I post only to help you. If you don’t want my input, just pm me rather than posting a sarcastic response. 

The best I can tell about the NuPrime digital transport (CDT-8 PRO) and companion DAC (DAC-9) is that the CDT-8 PRO transport can be selected to up sample to higher sampling rates ONLY for the purpose of digital stream data transmission via a compatible digital cable to a downstream DAC (e.g., NuPrime DAC-9) capable of receiving and processing that data stream for a particular digital cable and input. That DAC processing can be done with the received input native digital signal rate from the transport, or with some up- or down-sampled digital signal rate once in the DAC.

That is--and despite what the NuPrime CDT-8 PRO manual and literature states--the NuPrime CDT-8 PRO does not up sample and then down sample to the target signal rate before sending out its digital data stream to the downstream DAC. My Theta DAC confirmed that only the CDT-8 PRO output streams clocked at 44.1kHz and 48kHz would lock on the Theta DAC input receiver.

And I am not convinced that one can strip jitter from a data stream simply by applying up sampling and down sampling tricks. As I said, the native output circuit jitter is quite high from the CDT-8 PRO. Maybe Steve Nugent can chime in on this point.

OP: "Here’s what happens when one presses the the Nuprime CDT-8’s OS button [the central one on the bottom row of the remote], and then dials up to the desired PCM OS rate, say, 48K x 2 = 96K [by pressing the right button on the bottom row]... the DACs I have used, the Jay’s Audio and the Denafrips Pontus, detect that OS input [PCM 96K], while registering that rate in their displays [an LED display for the Jay’s, a light for the Denafrips],...[snip, snip]"

That is what I am saying here: "The best I can tell about the NuPrime digital transport (CDT-8 PRO) and companion DAC (DAC-9) is that the CDT-8 PRO transport can be selected to up sample to higher sampling rates ONLY for the purpose of digital stream data transmission via a compatible digital cable to a downstream DAC (e.g., NuPrime DAC-9) capable of receiving and processing that data stream for a particular digital cable and input. That DAC processing can be done with the received input native digital signal rate from the transport, or with some up- or down-sampled digital signal rate once in the DAC."
In short, I agree with you. So where is the disagreement? It’s not with me, so you need to elaborate your position if you disagree..

OP: "So, with all due respect, I do not know know you mean when you say that "the NuPrime CDT-8 PRO does not up sample and then down sample to the target signal rate before sending out its digital data stream to the downstream DAC."

I said the following: "That is--and despite what the NuPrime CDT-8 PRO manual and literature states--the NuPrime CDT-8 PRO does not up sample and then down sample to the target signal rate before sending out its digital data stream to the downstream DAC." It is not my language, but that of NuPrime. Your complaint is misdirected.

OP: "If your Theta DAC does not have OS-capability, then, OF COURSE, it [yourTheta DAC] "confirmed that only the CDT-8 PRO output streams clocked at 44.1kHz and 48kHz would lock on the Theta DAC input receiver." That is what a NOS DAC does. But that is not what the OS-capable Jay’s Audio and Denafrips DACs do when fed an OS signal from the Nuprime CDT."

My Theta DSPro basic IIIa is an 8x OS DAC. Is the CDT-8 PRO transport capable of up sampling a 44.1kHz signal to a 352.8kHz signal? Yes, but the CDT-8 PRO failed to deliver the signal to the Theta DAC. Why? Because the Theta DAC only accepts 44.1kHz or 48kHz INPUT data signals and only over-samples the digital data stream to 8x during digital processing once in the DAC. So you see, it depends upon how the DAC processes its digital signal after receipt, and OS means a lot of different things depending upon a given DAC. This may be more an issue about up-sampling digital data streams at an input receiver of a DAC vs. oversampling digital data once inside the DAC. Just saying..

OP: "I have to wonder.... Do you have some brief [sic] to write against the Nuprime DAC? Otherwise, why are you denying the obvious: It does have the capacity to send OS signals to OS-capable DACs."

I have no bias against or in favor of the DAC-9. I did not like the CDT-8 PRO transport, as it has high output jitter and did not improve the SQ of my audio system. I have no opinion about OS v. NOS transports DACs of any manufacture.

Be grateful for the input you received. A lot of original posts end up without any replies.

OP: Best of luck in your search for good CD playback. 

OP: what are you now using as a transport?

Yeah, I just realize-read that line. In any event, you’ve already made the decision to buy a Jay’s Audio DAC. So the question is actually reduced quite a bit to the singular issue about whether a OS transport is better than a NOS transport. It seems to me that you can answer that question with your present setup. Just compare the SQ of your system with the CDT-8 Pro set in NOS mode vs. OS mode. If you prefer the SQ of your setup in OS, then the issue is settled. If you don’t, then get the Jay’s Audio CDT2 MK2 transport. 

OP: I guess everyone, including you, has failed to explain or discuss the reasons to even consider a OS transport. I don’t see any inherent advantages for selecting an OS transport over a NOS transport. And those who market such OS transports fail to persuade the reader of any perceived advantages an OS transport affords. In the end, it’s the sound quality of the entire audio system that matters. I’m simply not convinced an OS transport would improve the sound quality. Seems like marketing hype absent such compelling reasons. 

OP: I’m speaking about the choice of transports. From your original post, I gathered you intend to keep the Jay’s Audio DAC.

Bigkidz likes a musical transport over an analytical one. And he didn’t like the CDT-8 Pro because it was not musical. I came away with the same conclusion and suspect it’s high jitter output as the basis for that conclusion. The Jay’s Audio CDT2 MK2 is extraordinary in its presentation of Redbook audio discs. Not surprisingly, it has very low jitter.

OP: You are the only one who can answer your questions to your satisfaction and finality. The feedback of others has little value because their system will differ from your system. Just buy the Jay’s Audio transport and evaluate it in your system. If you’re in the US, then you should speak with Mike Powell, who is the US distributor/dealer for Jay’s Audio products. Mike offers a money-back guarantee or store credit if you don’t like the Jay’s Audio transport.

I see you’re in Canada. Mike might cover Canada. Give him a call to ask.