Using NDX as transport, digital out

So setting the NDX to enable digital out it has native mode or 24bit/96KHz - I assume the 24/96K relates to the maximum performance the coax digital interface can support.

I can see the advantage of selecting fixed 24/96 output because I don’t have to worry about the odd album I have which is a 192K download BUT how good a job does the NDX do of this auto-scaling? Would I be better going ‘native’ output and work around the odd 192K albums (either converting the albums or perhaps I can get assett to do something on the fly)?

It’s no problem to play 24/192 via the SPDIF out. The 24/96 setting is there so that you can use a DAC that will not support a higher sample rate. I’ve never tried it, but I assume the NDX just downsamples to 96 if you use this setting.

So it’s only as a down scaling thing? I mean it doesn’t rescale all streams to 24/96? So unless the stream is greater than 96K then it won’t touch the stream… tbh I’m being lazy because can test this just by looking at the indicators on the dac. :wink:

Update… it rescales ALL traffic to 24/96. My feeling is if the NDX is playing with the stream then it partially negates having an external DAC. I think I’ll leave it native and widger the odd 192K album I’ve got.

You don’t need to widger anything! Just leave it native and play the 24/192 stuff.

Wilco… :slight_smile: Thanks for the advice.

Sorry, I was under the WRONG impression that the digital out was maximum 96K… my mistake.

in spdif, only 24/96

Internet radio (Windows Media-formatted content, MP3 streams, MMS)
Playlists (M3U, PLS)
MP3, AAC (up to 320kbit/s, CBR/VBR)
Apple Lossless (from iPod)
Windows Media-formatted content-9 (up to 320kbit/s) WAV and FLAC (up to 24bit/192kHz via UPnP or USB only) AIFF, LPCM 16/24, Ogg Vorbis
vTuner 5* full service

This is spdif out… working fine with 24/192K :slight_smile:

digital out is spdif, like naim dc1 cable connection. So it goes not higher than 24/96 in digital out. But works fine however, must downsample to 24/96 probably.
Digital out in usb can go to 24/192. It’s what i pasted from naim ndx specs on naim site.

hmmm… not sure about that. I’m using the coaxial digital out and the DAC is showing 192K which is correct for the file.

not sure also. It’s just written for the ndx. However the ndac can read 24/192 and even dsd. So i don’t know how it works.
Perhaps @Simon-in-Suffolk knows? he had ndx and ndac before.

The NDX outputs up to 24/192 through its SP/DIF - I know, I see that. The early models didn’t do that.

thanks for claryfing. So an error on the site.

There is no error, but perhaps the wording is a little confusing. What Naim mean is that you have the option to downsample to 24/96 if that is all that your DAC can support (which would be a rarity these days.) Perhaps also there is confusion with optical SPDIF, which officially only supports 24/96, but this does not apply to electrical SPDIF.

Just wondering why you need NDX as transport? Alternatively and better, cheaper (I think) is a combo of MM+Audirvana+Gustard U16, and you can go up to PCM 32bit/768KHz , DSD512, DoP and Native DSD if you want. Of course you need USB if you want to go higher than 24bit/192KHz.

I use the NDX as a network bridge, inputting CD/DVD, UpNP, TV and outputting to an M Scaler/DAVE. I stated steaming as an experiment with a second hand NDX as a cheap but one box solution and it all escalated from there…

I have no need or desire to go higher than 24/192 or DSD64 native. The NDX>M Scaler>DAVE combination brings excellent results.

No, SPDIF can operate at 192/24/2 and my early NDX was quite happy doing this… therefore that is its maximum frequency.
The older version of AES is limited to 96/24/2, so I believe setting in the digital out of the NDX is some sort of legacy compatibility mode for older DACs… from memory that function has disappeared with the newer streamers as most DACs support at least up to 192/24/2 now

Okay… so I guess you’ve realised I’m doing some playing around with an external DAC :wink:

Slight problem which might be a number of things… at the start of a new album there are a couple of stutters when the sample rate LED on the dac cuts in and out along with associated audio drop. It’s like it’s taking a few seconds for the digital feed from the NDX to settle down. Seems to happen with all frequencies or at least the 44, 96, 192 albums that I have to test with. Once the first 5 seconds or so are over it’s sorted itself out and the rest of the album is fine.

The only thing I can think of is jitter on the digital input to the DAC. At the moment, whilst waiting for a proper 75Ohm cable through the post, I’m using an old 50cm audio phono-phono. Could it be the cable causing this?

The NDX changes its SPDIF link stream data rate almost immediately.
Unless there is a fault with your NDX, it sounds like your connected DAC is taking time to re synchronise to the new SPDIF link protocol data rate change when the encapsulated media sample rate changes.

Also does your NDX say ‘locked’ on your digital input. That confirms your NDX is locked to your input SPDIF link protocol data rate. And does it lock quickly when changing sample rate?

This is using digital OUT on the NDX using an incoming network stream so not sure where I’d see the ‘locked’ message. I’ve got the NDX status showing buffer level and it’s immediately at full level so I don’t think it’s an issue with the network stream coming in to the NDX; plus you don’t see this issue using the NDX for transport and DAC function so audio out from the NDX.

Could it be the data stream taking time to settle on the SPDIF link due to jitter? It’s just I’ve read of issues with jitter on coaxial SPDIF if the cable is wrong or faulty. In fact this is the reason cited in the DAC manual.

You see it on one of the NDX display screens and on the Naim apo