Upgrade dCS network bridge to Lumin U2 mini to drive Kii Three?

hi,

I am currently using a dCS network bridge (legacy product now) with Kii Three active speakers which I really like, via the Kii Control (coax input).

The dCS network bridge doesn't have a USB output so I can't use USB to the Kii Control.

I am thinking about changing the dCS Network Bridge to a newer streaming transport like the new Lumin U2 mini. The dCS is now 5 years old and it's not future proof since it's now a legacy product.

However, upgrading to the Lumin U2 mini that has more sampling rates may not make sense in my use case since I am going to be limited by the DAC from my Kii Threes. It seems that the DAC from the Kii Three got really good reviews but on coax limited to 24/192 PCM when using coax like with my dCS NB.

Should I upgrade(?) to Lumin U2 mini, I would have the possibility to connect to the Kii Control by USB and therefore use more of the capability of the Kii internal DAC with higher sampling rates.

Would such a move make sense? from a technical perspective it looks like it at first glance, but what about SQ...?

Thank you for your thoughts in advance! 

NB: These are the specs from Kii Three:

Direct to Kii speakers: AES/EBU up to 24-bit/192kHz PCM

USB to Kii control input supports sample-rates up to 384 kHz PCM, as well as DSD 64 and 128 --> not possible in my case since dCS doesn't have USB capability

Based on my experience with the Kiis, you won't  hear  much difference if any at all if you make the switch.

Try the iFi Zen Stream, it does wonderful things SQwise, it maybe cheap but don't let that discourage you.

19 hours ago, pam1975 said:

However, upgrading to the Lumin U2 mini that has more sampling rates may not make sense in my use case since I am going to be limited by the DAC from my Kii Threes. It seems that the DAC from the Kii Three got really good reviews but on coax limited to 24/192 PCM when using coax like with my dCS NB.

Should I upgrade(?) to Lumin U2 mini, I would have the possibility to connect to the Kii Control by USB and therefore use more of the capability of the Kii internal DAC with higher sampling rates.

The higher sample rate support via USB matters only if you listen to a lot of 352kHz or DSD sources.  With USB, these only get resampled by Kii internally once.  With coax or AES, you'll have to resample the source to a proper sample rate first (using the streamer or Roon, or something else), then it gets resampled by Kii internally for a second time.

As for SQ, you'll need to search for other Kii users' feedback.

I have a pair of Kii Threes but never used it via a Dcs. In my experience most of the time any of the spdif inputs work better than direct USB when used with a variety of servers including directly from the Roon Nucleus…. its simply less harsh and 2 dimensional.…Put a USB noise filter device from either Intona or iFi and the sound improvement can match or better the spdif input ..but it does require some tweaking with power supplies and earthing to get there.

To be honest, i dont hear an improvement in sound beyond 192k within USB so i wouldnt move to USB just for the higher sample rates alone. Also, even with USB and a 384k sound source, the Kii Controller will display a  sample rate at 192k which probably means that its downsampled anyway.

If you must, I hear the new iFi NeoStream is worth a try and it has all the output formats incuding USB and AES/EBU for you to make the comparisons. See if you could get one on trial.

thanks everyone, great answers and really helpful! :)

On 10/19/2022 at 3:55 AM, wklie said:

 

The higher sample rate support via USB matters only if you listen to a lot of 352kHz or DSD sources.  With USB, these only get resampled by Kii internally once.  With coax or AES, you'll have to resample the source to a proper sample rate first (using the streamer or Roon, or something else), then it gets resampled by Kii internally for a second time.

thanks but why does it have to be resampled first when using coax or AES? i get the resampling done by Kii's internal DAC but I don't get why it's done before that by the streamer or Roon?

I think there is some confusion here.  USB can accept higher sample rates than SPDIF, AES, TOSLINK that are limited to 24 / 192. 

What the kii does internally is a bit more complex with USB.  I have not researched it as I sold my Kii's. As others have noted the USB input of the Kii control is finicky with some devices.

I would get a demo of the Lumin before you buy it....On your system.

rjf

7 hours ago, pam1975 said:

thanks but why does it have to be resampled first when using coax or AES? i get the resampling done by Kii's internal DAC but I don't get why it's done before that by the streamer or Roon?

Assume you use AES or coax.

When you play 352.8kHz file, it cannot be passed without resampling via AES / coax because the latter is limited to 192kHz.  You'll need to downsample the 352.8kHz to 176.4kHz first in order to feed it to Kii, which will then resample it internally a second time to 93.75kHz.

DSD is similar.  You'll need to convert it to PCM first before passing it via AES/coax because the latter only passes PCM.

2 hours ago, wklie said:

 

Assume you use AES or coax.

 

When you play 352.8kHz file, it cannot be passed without resampling via AES / coax because the latter is limited to 192kHz.  You'll need to downsample the 352.8kHz to 176.4kHz first in order to feed it to Kii, which will then resample it internally a second time to 93.75kHz.

 

DSD is similar.  You'll need to convert it to PCM first before passing it via AES/coax because the latter only passes PCM.

got it, thanks!

8 hours ago, bobfa said:

I think there is some confusion here.  USB can accept higher sample rates than SPDIF, AES, TOSLINK that are limited to 24 / 192. 

 

What the kii does internally is a bit more complex with USB.  I have not researched it as I sold my Kii's. As others have noted the USB input of the Kii control is finicky with some devices.

 

I would get a demo of the Lumin before you buy it....On your system.

 

rjf

 

thank you Bob...why the Lumin more specifically? and which model? U1?

Any other streamer.  Make sure you understand the software and the hardware.  Ensure you have a handle on the things like bit rates.  There seems to be some confusion in the thread.  

On 10/18/2022 at 8:27 AM, pam1975 said:

hi,

 

I am currently using a dCS network bridge (legacy product now) with Kii Three active speakers which I really like, via the Kii Control (coax input).

The dCS network bridge doesn't have a USB output so I can't use USB to the Kii Control.

 

I am thinking about changing the dCS Network Bridge to a newer streaming transport like the new Lumin U2 mini. The dCS is now 5 years old and it's not future proof since it's now a legacy product.

 

However, upgrading to the Lumin U2 mini that has more sampling rates may not make sense in my use case since I am going to be limited by the DAC from my Kii Threes. It seems that the DAC from the Kii Three got really good reviews but on coax limited to 24/192 PCM when using coax like with my dCS NB.

Should I upgrade(?) to Lumin U2 mini, I would have the possibility to connect to the Kii Control by USB and therefore use more of the capability of the Kii internal DAC with higher sampling rates.

 

Would such a move make sense? from a technical perspective it looks like it at first glance, but what about SQ...?

Thank you for your thoughts in advance! 

 

NB: These are the specs from Kii Three:

Direct to Kii speakers: AES/EBU up to 24-bit/192kHz PCM

USB to Kii control input supports sample-rates up to 384 kHz PCM, as well as DSD 64 and 128 --> not possible in my case since dCS doesn't have USB capability

 

 

In this price range I would keep the dCS Network Bridge and stay away from USB. If you really want to make a step forward, I recommend the Grimm MU1 especially because of it's excellent upsampling. But that is a completely different price category. And with the Grimm, it's ROON only.

thank you, it's a useful perspective. I discovered the Rose RS150B recently and I really like its specs, but I haven't listened to it yet, i'm looking for a distributor locally. Looks a bit more future-ready than the dCS NB although for sure, there is nothing inherently wrong with it...

If you did not change directions yet, I would recommend connecting the dCS directly to the master Kii with Aes. You might like what you hear. Make sure the cable you try is a good one though. 

Yes, curious what you went with @pam1975. Do keep us informed!

Any updates on the RS150B??