Hi All, I have been using a raspberry pi with Allo Hat and an Audio Note 1.1x non oversampling dac. I am now replacing this set up with a Naim NDX2 streamer. I remember I made some adjustments to roon to take account of the non oversampling dac and now I have the Naim streamer I want to adjust these back. Unfortunately, I cant find my original post concerning that change. Please could someone let me know which adjustments I need to make so I can optimise performance for the Naim? Many thanks, Chris
The NDX2 is Roon Ready, so it automatically tells Roon the settings it wants.
It’s also not correct, by the way, that the DAC is non oversampling. The SHARC processor directly in front of the DAC oversamples the signal before feeding it into the DAC. This is from the ND555 whitepaper, but it’s the same for the NDX-2:
In the ND 555, oversampling and bespoke digital filtering is performed in an Analogue Devices SHARC ADSP21489 digital signal processing (DSP) chip located on the digital card. This DSP chip has the advantage of low power requirement. Digital signals at multiples of 44.1kHz sampling rate (44.1kHz, 88.2kHz, etc) are oversampled to (16 Ă— 44.1 =) 705.6kHz, and those at multiples of 48kHz sampling rate (48kHz, 96kHz, etc) to (16 Ă— 48 =) 768kHz.
Anyway, my NDX2 settings (default, except I might have enabled the MQA core decoder setting):
Of course, if you think that Roon makes a better conversion, you can go to MUSE and convert everything to the maximum of 384 kHz that the NDX2 accepts as input. I tried this in the past but if there is any audible difference at all, I preferred letting the NDX2 do its thing. YMMV.
As you can see here in the specifications, the maximum input is 384:
And I can’t find your old post on the forum either.
1 Like
Thank you very much Suedkiez. I will check my settings against yours. I am a relative beginner in understanding the inner workings of roon really.
If you want to play with it, the upsampling in Roon is done in MUSE > Sample Rate Conversion > Max PCM Rate. (I usually have it off because I let the NDX2 do its thing and my source material never goes to 384. Otherwise you may want to choose „For compatibility only“).
Though even then, it will still oversample to the 705.6/768 internally, you can’t change that.
And note that I have set it to “fixed volume” because I feed it into a NAC 252, and therefore using Naim’s system automation to control the volume by Naim’s remote in the preamp, as Naim recommends.
You could theoretically switch it to variable volume, and then you could control the volume via Roon. However, the digital volume control in the NDX2 is implemented only in 32-bit and without a lot of effort, as Naim didn’t really intend it to be used. It’s only there because digital volume was needed to achieve some certification, AirPlay I believe. On the other hand, people on the Naim forum tried it and didn’t report any really audible poor effects (and this says something on the Naim forum, where they usually invent all kinds of effects out of thin air). So YMMV, again 
I’ve never seen this before - do you recall where you found it?
It’s common knowledge on the Naim forum and by all accounts the info was freely shared there by Naim staff (although it’s not in the official - very sparse - documentation, but Naim people hang out on the forum all the time and there’s lots to learn from them that is never mentioned anywhere else).
I can’t find the original source anymore and it may well have been on the defunct old forum, but here’s a thread with many regulars like Simon who is always reliable:
The fact that they provide system automation in the first place, so that the NDX2 remote can control the NAC volume by turning the NAC volume motor, is another hint. They could have saved on that if they thought otherwise. (And I think they continue to do so in the New Classic and the NSS 333 - instead of implementing improved digital volume in the streamer, they put the fancy digitally controlled ladder volume control into the new preamp instead).
Finally, mostly to the OP, @Christian_Bolton:
32-bit digital volume is generally known to be problematic because reducing volume means that the least significant bits are cut off, and with only 32 bits to play with it might reach into audible bits at least if reduced to low levels. (That’s why Roon’s DSP volume is implemented in 64 bit and data gets increased to 64 bits before volume changes are calculated, then downsampled again).
You can try it yourself, of course. With variable volume on the NDX2 it might become more audible the lower you turn the volume in the NDX2, compared to the same audible volume with the NDX2 as fixed and the volume controlled by the amp. Though the quality of the amp and its volume control will play a role, too. Though if you set it to fixed, make absolutely sure that your amp volume is turned down before raising it slowly.
Maybe you are lucky and it sounds the same to you
Been there, read that… 
However I’ve never - that I can recall anyway - seen any claim that variable is calculated at 32 bits. That’s what was interesting.
I’m sure that this was said many times but can’t be arsed to find it
Ah well, never mind. I was just hopeful you’d found something definitive where I’d failed. 
I am very disappointed in myself that I didn’t As I purchased my Naim in the fall of 2020, there’s one possibility that I discussed volume options with my dealer back then and they told me. But, although I had a decades long relationship with this dealer, they were one of the oldest Naim dealers in Germany, and were one of the few I really trusted, I feel too sure about the 32-bit thing for not having had a separate corroboration. I guess you can always email Naim support, poke Simon or ask one of the Naim guys on the forum:
(Side note: Sorry I had forgotten that you were on the Naim forum just as much )
I can’t tell you how many bits are involved, but maybe this explains what you need to know about volume control options:
1 Like
You’re not expecting me to remember what I posted five years ago are you? 
1 Like