Significance of the digital source in the output SQ
Posted by: Paristhea on 13 June 2016
I was advised by a dealer friend, London based, when he suggested that the digital source is as important as the analogue source. Personally, i found that odd, as i am with the opinion that if you have a high definition digital recording, then why it is important if i use a Mac Mini as my source and storage of the zero's and ones, that make up the song? My point being, how can you add noise in a digital signal consisting of zeros and ones? I am assuming that the DAC is only counting the zeros and the ones, right?
It seems Naim had done a study on this, so i like to ask Naim as well as forum members opinion on the issue, with explanation please.
Huge posted:Hi Paristhea, I suggest searching the forum for "bits are bits": you'll get many threads that explain why this is a vast oversimplification.
Some of the salient points include:
RFI
Power Supply Noise
Jitter / Re-clocking / Buffering
Digital Processing / Oversampling / Noise Shaping / Digital Filters
DAC quality
Effect of ultrasonic spuriae on analogue amplifiers.
Quality of analogue filters
Quality of analogue output stagesPlenty for you to research.
Indeed !!!! I will qualify for a PhD by the time i finish researching all those things. Perhaps i should not have entered this topic/minefield at all, 
Eloise posted:
At the end of the day ... why take anyone's opinion. You are best of trying things for yourself.
Quite.
dayjay posted:The gubbins I was referring to would include different USB cables, devices like the USB Regen and Audioquest Jitterbug, both of which I use, converters to allow USB to connect to an Ndac etc etc. Almost all that II have tried has an impact on the final sound, some more than others. When I got my Hugo for a while I connected just about every device in my house with a digital out including various PCs and Macs, phones, Virgin Box, TV etc and they all sounded very different. After a lot of experiementing to decide on my transport I ended up with a Naim streamer, a Mac Book Pro and a Mac Mini (both on Audirvana) and choose the Mac Book Pro with some gubbins attached as my best option - sadly the gibbons where not available at the time.
I use the N272 DAC/Streamer/Preamp for all above. And a Mac mini, but no USB cables, as ethernet does the job.
In your case what is the Macbook Pro doing in the chain of things or the Mac mini? I mean why do you need both? Audirvana i assume is like J River (uPnP software)? And finally, at present, you do not use all those USB cables, Regen and other devices any more?
Eloise posted:I'm going to put forward a different reply.
Many people are saying that UPnP servers and the server hardware and ethernet cabling matters. I say it doesn't. My experience is that (unless you have errors) that MinimServer running on a Linux install on a Dell Optiplex sounds identical into my NAC-N 272 as LMS (as a UPnP server) running on the same hardware or Asset running on my MacBook.
Of course I accept I may be deaf!
What can sound different is any computer directly attached - that is via USB or even via a USB to SPDIF converter; as noise and other undesirable interference can cause the DAC to react differently; there are even devices out there which claim to offer improved isolation between the computer and the DAC; though there is only anecdotal evidence (listening testing) to support this claim.
At the end of the day ... why take anyone's opinion. You are best of trying things for yourself. There is a phrase that comes to mind ... "Keep your mind open ... but don't let your brains fall out!"
I like the above theory, and i must say i share the same opinion.
I will further add, that if therefore the signal is sent via wifi across to the NAIM N272 directly, (no cables or anything else in between), then there is no noise transmission to the DAC, right? Can RFI and other noise be transmitted wirelessly?
Wireless is even worse - you're intentionally directing a modulated radio signal into a box containing sensitive analogue electronics. At least with wired Ethernet the RFI is creeping in through a gap in the back door rather then being welcomed in with open arms!
And then there's the alternative method of "listening". This is a process whereby one forgets all the gibbons, gubbins and cribbing and what dealers or forumites tell you and make an assessment as to the quality of the music you are hearing. If this sounds good to you, go in peace brother and don't sin again.
SJB
Ah!, but then you never quite know...
Was it real? Was I just imagining it? So instead of going in peace, you go to pieces! 
Mac Mini with Audirvana has been widely cited as an excellent source, favourably compared to a number of Naim front ends. Audirvana is not a uPnP server, but a renderer: the part that converts the digital file into a stream that feeds the DAC. (uPnP servers make the files available to a networked renderer - Naim streamers consist of renderer+DAC - If the files are stored on the MM no uPnP is necessary for Audirvana.) The MM USB output (best quality with Audi because it bypasses the inbuilt souncard completely) is not eletrically 'clean', so unless the DAC has galvanic and rf isolation an isolator is needed - I use a Gustard U12 USB/SPDIF isolator/converter.
My personal experience has been MM/Audi/GUS into Hugo is better than ND5XS into Hugo, which is better than ND5XS+XP5XS. Others have found similarly with other Naim streamers.
The MM/Av/Gus/Hugo is a very cost-effective approach (which strangely seems to put some people off!) However, returning to the original question, I note you have a 272, so initially why not try Audirvana on your MM (a free trial is available)? Plug into the digital input of the 272? Unfortunately the 272 doesn't have a USB input , so you'd have to use a convertor for best quality -I'd recommend the Gustard, though as it is only available from overseas (e.g. via a well known online auction site or bookseller named after a South American river), you would have to prepared to take a 'punt' on it. Alternatively the MM's optical out, but that is knowinly not as good qhality.
Huge posted:Wireless is even worse - you're intentionally directing a modulated radio signal into a box containing sensitive analogue electronics. At least with wired Ethernet the RFI is creeping in through a gap in the back door rather then being welcomed in with open arms!
Huge, it would be a digital signal sent wirelessly, nothing analogue to it, yet, unless i misunderstood what you mean.
In any case, i only use ethernet cables because wirelessly you lose some resolution i believe on Naim. Plus my N272 is in a wooden "slot", meaning there is no space for the antenna.
Paristhea posted:Huge posted:Wireless is even worse - you're intentionally directing a modulated radio signal into a box containing sensitive analogue electronics. At least with wired Ethernet the RFI is creeping in through a gap in the back door rather then being welcomed in with open arms!
Huge, it would be a digital signal sent wirelessly, nothing analogue to it, yet, unless i misunderstood what you mean.
In any case, i only use ethernet cables because wirelessly you lose some resolution i believe on Naim. Plus my N272 is in a wooden "slot", meaning there is no space for the antenna.
Yes, you misunderstood. An Ethernet cable acts as an inefficient antenna that picks up radio waves (as interference - i.e. RFI) and (unintentionally) conducts part of that energy (i.e. interference) into the case of the streamer. A WiFi antenna acts as a fairly efficient antenna and (intentionally) shoves most of that RF energy inside the case of the streamer. Once inside the case that RF energy bounces around and affects thing like the DAC and other analogue electronics.
The input signal may be digital, but digital signals interact (harmfully) with analogue electronics.
Keep using the wired Ethernet, it is better.
Huge posted:Paristhea posted:Huge posted:Wireless is even worse - you're intentionally directing a modulated radio signal into a box containing sensitive analogue electronics. At least with wired Ethernet the RFI is creeping in through a gap in the back door rather then being welcomed in with open arms!
Huge, it would be a digital signal sent wirelessly, nothing analogue to it, yet, unless i misunderstood what you mean.
In any case, i only use ethernet cables because wirelessly you lose some resolution i believe on Naim. Plus my N272 is in a wooden "slot", meaning there is no space for the antenna.
Yes, you misunderstood. An Ethernet cable acts as an inefficient antenna that picks up radio waves (as interference - i.e. RFI) and (unintentionally) conducts part of that energy (i.e. interference) into the case of the streamer. A WiFi antenna acts as a fairly efficient antenna and (intentionally) shoves most of that RF energy inside the case of the streamer. Once inside the case that RF energy bounces around and affects thing like the DAC and other analogue electronics.
The input signal may be digital, but digital signals interact (harmfully) with analogue electronics.
Keep using the wired Ethernet, it is better.
Fair enough. I realise the process it is much more complicated than i had ever thought it would be. Thanks Huge.
Paristhea posted:dayjay posted:The gubbins I was referring to would include different USB cables, devices like the USB Regen and Audioquest Jitterbug, both of which I use, converters to allow USB to connect to an Ndac etc etc. Almost all that II have tried has an impact on the final sound, some more than others. When I got my Hugo for a while I connected just about every device in my house with a digital out including various PCs and Macs, phones, Virgin Box, TV etc and they all sounded very different. After a lot of experiementing to decide on my transport I ended up with a Naim streamer, a Mac Book Pro and a Mac Mini (both on Audirvana) and choose the Mac Book Pro with some gubbins attached as my best option - sadly the gibbons where not available at the time.
I use the N272 DAC/Streamer/Preamp for all above. And a Mac mini, but no USB cables, as ethernet does the job.
In your case what is the Macbook Pro doing in the chain of things or the Mac mini? I mean why do you need both? Audirvana i assume is like J River (uPnP software)? And finally, at present, you do not use all those USB cables, Regen and other devices any more?
My digital set up is Mac Mini running Audirvana 2, Audirvana remote control on a IPad, Jitterbug plugged into the USB port of my Mac Mini, decent USB cable running to a USB Regen which is plugged into my Chord Hugo. To my ears the sound is fantastic and on par with my vinyl set up. As I have added the different elements to the Mac Mini and Hugo, and as Audirvana has been revised, I have easily been able to hear the differences at each stage.