APEX - while the Vivaldi DAC is away for updating

Well I’m in the planning stages for releasing my Vivaldi DAC for its APEX upgrade. Currently using the DAC along with the Upsampler and Clock.

I’m assuming that if I put another DAC in its place, I will need to abandon the Clock for the duration. I don’t believe it can work only with just the Upsampler in play.

And I’ll need to turn Dual AES off since I’ll only have a single output from the Upsampler into the DAC. And I’ll need to change the Output Sample Rate down (avoid 352/384/DSDx2) since my Schitt Yggdrasil only will take up to 192k. And change Sync Mode from Auto Word Clock to Master

Let me know if I’ve got this right or am missing anything. Hoping to deliver the Vivaldi DAC next month to my dealer to get shipped back East.

Hey Steve that all sounds right to me, except I think you can still use the external clock on the upsampler. I haven’t tried it, but the timing on the external clock should be better than the internal clock on the upsampler. How much that improves things I don’t know. Even if the upsampler isn’t “in sync” with the dac I’d think gains could be had there. It’d be nice to have some dcs folks say definitively that the clock helps the upsampler on its own, the clock helps the vivaldi dac on its own, and then using the clock for both provides another bump in performance.

But yes, clocking aside, keeping output on one AES <= 192khz sounds right to me.

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Thanks for your feedback. Been through all the manuals and I got the impression that clocking with the Master clock would only be of value it was essentially end-to-end with the digital datastream leaving the source, entering the Upsampler and and ending in the DAC. But a member of my dealer team was, like you, uncertain.

Hoping someone from dCS steps forward with the definitive answer.

Hi Steve,

@Chuck is pretty spot on. If you put a DAC in the system which does not have a Clock input (such as the Yggdrasil) you can leave the Clock connected to the Upsampler - you’ll just need to change the Dual AES and output rate settings.

The Clock will still provide an improvement to the system, as there will be less jitter on the AES output of the Upsampler with it in situ, but the improvement will not be as big as it would be if the DAC could be clocked.

It will probably make your life a bit easier not needing to change more settings around on the Upsampler as well!


Thanks for your guidance. Will just disconnect the DAC clock cables. Should I continue keep the setting for Sync Mode to Word Clock 1-2 Auto?

Also, as I’m using Roon for playback is it necessary to use it to limit it’s max sample rates for PCM and DSD or simply control output for source material via the Upsampler to the Yggdrasil DAC?

Yes, that’s the way to do it :+1:

I would say probably best to have the Upsampler limit the output rate, but if you find limiting it in Roon more convenient then by all means go with that - either will work correctly.