NDX, nDAC and 555PS - Some Interesting Tests

Posted by: Asenna04 on 28 March 2011

I have been testing the new NDX over the last few days. My system is as follows:

 

SB Touch / USB Memory Sticks

nDAC

555PS

Hi-Line

252/Supercap

250

NAC A5 Speaker Cable

Ovator S400

 

The are 3 Powerlines on 555PS, Supercap and 250.

 

I let the NDX powed up and conencted to UPnP source and playing on mute for a few days.

 

Test 1 - NDX/555PS

I replaced the nDAC with the NDX powered by 555PS. The SQ was not on par with nDAC. It seemed the nDAC has more top end detail and tighter bass.

 

Test 2 - NDX

I then just decided to run the NDX on its own without the 555PS. The sound was much better. Better even then the nDAC/555PS. This got me confused. Sure that cannot be true. I scratched my head and wondered what be wrong. So I proceeded to Test 3.

 

Test 3 - nDAC

Based on what I found on Test 2, I decided to run the nDAC on its own without the 555PS playing from USB Memory. And again, I got much better sound then nDAC/555PS. So this pointed to setup or problem with 555PS. I checked the Bundy cable and it was very close (resting on) the power plugs where they connect to the wall sockets. The Hi-Line was also very close. So I moved them and the Bundy was well clear of all power cables and the Hi-Line was moved away as well.

 

This made a big difference to the sound. The nDAC/555PS sound much better then the nDAC on its own. Better timing, better top end, and bigger and tighter bass. This was a huge revelation. Everything was sounding great.

 

Test 4 - NDX Digital Out into nDAC/555PS

So I now connected the NDX playing from USB Memory with its digital out into the nDAC/555PS (via BNC to Phono Digital cable). I could not hear any difference between that and nDAC/555PS (Test 3)

 

Test 5 - NDX Digital Out into nDAC/555PS Vs NDX Analog Out

Now it gets interesting! With setup as Test 4 above I added a spare standard Naim lavender interconnect to connect the NDX Analog out to the Tuner signal input of the 252. The nDAC was still connected via the Hi-Line to the CD signal input of the 252. The NDX was therefore outputing both digital and analog signals. The digital to nDAC/555PS and Analog to 252. The digital signal went into nDAC/555PS and the analog output of that went into 252.

 

The results were shocking. I could not hear any difference when I switched the signal on the 252 via remote between the NDX and NDX/nDAC/555PS. I tried different tracks and the same the results was same. I could tell them apart.

 

I scratched my head again. If the NDX was sounding similar to nDAC, that would be fine. But how can the NDX sound the same as nDAC/555PS. Not even the Hi-Line was sounding different to the standard lavender interconnect! Shocking.

 

What does this mean? I could not come up with any possible explanation.

 

Test 6 - NDX/555PS Digital Out into nDAC Vs NDX/555PS Analog Out

 

After the shock of Test 5 above, I moved the 555PS to the NDX with the digital out still connected to the nDAC and analog out to 252. The nDAC was still connected via the Hi-Line to 252.

 

Results? I could not tell any difference on sound quality as in Test 5. But the big surprise again was that when I switched between the NDX/555PS signal on the 252 and the NDX/555PS/nDAC signal into the 252 I could tell them apart.

 

I could not believe it so I decided to do a blind listerning test. I asked my 8 year old daughter to help me. I asked her to decide which input on the remote was A and which was B and not reveal her decision to me. I then closed my eyes and asked her to switch to A or B. So now I did not even know which source signal was playing and switched between the two a number of times for different tracks. I could not really tell them apart, so picked what I thought was a better source and said A was number 1 on the remote (NDX/555PS/nDAC). I got it wrong, A was NDX/555PS.

 

What next?

So now I am confused, am I doing something wrong. Is this because the way I am running the test that is affecting the SQ of the results to be same? Surely not. The Analog signal is made in the individual boxes.

 

As for the Hi-Line, I thought maybe the Hi-Line was making up of the lack of 555PS on the nDAC. But this does not explain why the NDX would sound the same when the 555PS was on the nDAC.

 

This gives the conclution that the 555PS makes no difference to the SQ and the NDX is as good as the nDAC. But I have heard the nDAC get better when the 555PS is added to it. This makes me wonder if what I heard was real or percieved. Surely it is much better to hear any difference when you simply switch between different signals and play the first signal and then stop and play the second signal.

 

I got the NDX to test against the nDAC and decide which to keep. I did these tests last weekend and I am still thinking what I should do. But I am very confused now.

 

Request

 

To validate my findings, I would like to request other forum members who have the NDX, 555PS and nDAC to try Test 5 and Test 6. All you need is an extra interconnect (ideal if you have another Hi-Line). I know from other forum posts that aysil has all 3 and and some members who already have nDAC/555PS are planning to get the NDX.

 

Regards,

 

ASenna04

Posted on: 02 July 2011 by Hook
Originally Posted by pcstockton:
Originally Posted by AllenB:

Not actually bothered about 24/192 at this time.

Agreed.  As one of the first on the hires train (via DVD-A rips, SACD transfers and needledrops) I have never felt an improvement going between 24-96 and 24-192. 

 

16 to 24 bit - HUGE difference

24/48 to 24/96 - Mild/Subtle difference.

96 to 192 - Cant hear it. 

 

Albeit, all tests were done bbefore Naim DAC.

 

I will not pay more for 192.  That is for sure.  And I wont encode to it, waste of time and space.

 

It really doesn't have a place in my world..... just like 3D TVs.

 

Hi Patrick -

 

Thanks for your comments.   I suspect you are right, and that when it comes to sound quality, there really are diminishing returns at higher bit rates. 

 

We did some blind tests of 24/192 versus 24/96 a couple of weeks back.  Mrs. Hook has very good hearing, and was able to reliably tell the difference in test after test.  But my setup has changed significantly since then, so am going to re-run those tests today (the Mrs. being willing of course).  Settling on 24/96 (for now anyway) would make life a bit easier...

 

Part of the reason I became focused on 24/192 is that it proved to me to be a practical upper limit for working with large digital files.   I used a new Macbook Pro to try and do the conversions and editing (from 5.6mHz DSD recordings to different flavors of WAV and FLAC).  My first attempt at using Korg Audiogate's maximum resolution (32/192) was pretty frustrating.   Took too long to run the conversions.  Took too long to open, edit and close the resulting PCM files.   By contrast, manipulating 24/96 was very snappy.   24/192 was in-between, but still on the slow side, so it became the upper limit I thought I could deal with. Anything beyond was just too much work.  I know computers are getting faster, and disk storage is getting bigger and cheaper, but even at 24/192, it takes a gigabyte to store just 12 minutes of music!

 

Am starting to think that 24/96 might just be more practical.  After all, the more work that recording stuff takes, the less I want to do it.   So some tiny sacrifice in fidelity might just be worth it.  Oh well, I'll see what Mrs. Golden Ears thinks today.

 

Hook

 

 

 

Posted on: 02 July 2011 by Aleg
Hook Is there a specific reason you choose to do DSD conversions to the 96 / 192 range and not to the 88.2 / 176.4 range, the latter being in the line of exact multiples to the DSD sample rates of 2.8224 MHz and 5.6448 MHz, contrary to the prior? - Aleg
Posted on: 02 July 2011 by Hook
Originally Posted by Aleg:
Hook Is there a specific reason you choose to do DSD conversions to the 96 / 192 range and not to the 88.2 / 176.4 range, the latter being in the line of exact multiples to the DSD sample rates of 2.8224 MHz and 5.6448 MHz, contrary to the prior? - Aleg

 

Hi Aleg -

 

Thanks for bringing this up.   The Audiogate software gives me a choice of either conversion rate, direct to 88.2/176.4, or through an interpolation filter to 96/192.

 

My choice of 192 was influenced by a discussion I read on gearslutz (or AVS or one of the other pro audio sites -- I'll try and find it).  This one engineer was claiming that most modern dac's have an much easier time processing 96/192, so he thought is was a better idea to do the extra processing up front, rather than during playback.  None of the other engineers on that thread corrected him, so I assumed he knew what he was talking about.

 

I think I may have also been influenced by the HDX's support for 192, but not 176.4.  It seemed to lend credence to this argument that 96/192 was easier to do.

 

But I guess none of that really matters.  I should have asked the specific question:  does the Naim DAC and/or NDX care, since I will likely be using one of those two going forward.  If they don't, then as you point out, interpolating really makes no sense.

 

Fortunately, I have only recorded 22 albums so far (I picked ones that needed no pop/click editing in PCM, and all of head/tail editing was done in DSD), so running a new set of conversions at 24/88.2 would be easy to do.

 

Thanks again for making me think about this, and I would appreciate any further thoughts you have on the subject.

 

Hook

Posted on: 03 July 2011 by Aleg
Originally Posted by Hook:
Originally Posted by Aleg:
Hook Is there a specific reason you choose to do DSD conversions to the 96 / 192 range and not to the 88.2 / 176.4 range, the latter being in the line of exact multiples to the DSD sample rates of 2.8224 MHz and 5.6448 MHz, contrary to the prior? - Aleg

 

Hi Aleg -

 

Thanks for bringing this up.   The Audiogate software gives me a choice of either conversion rate, direct to 88.2/176.4, or through an interpolation filter to 96/192.

 

My choice of 192 was influenced by a discussion I read on gearslutz (or AVS or one of the other pro audio sites -- I'll try and find it).  This one engineer was claiming that most modern dac's have an much easier time processing 96/192, so he thought is was a better idea to do the extra processing up front, rather than during playback.  None of the other engineers on that thread corrected him, so I assumed he knew what he was talking about.

 

I think I may have also been influenced by the HDX's support for 192, but not 176.4.  It seemed to lend credence to this argument that 96/192 was easier to do.

 

But I guess none of that really matters.  I should have asked the specific question:  does the Naim DAC and/or NDX care, since I will likely be using one of those two going forward.  If they don't, then as you point out, interpolating really makes no sense.

 

Fortunately, I have only recorded 22 albums so far (I picked ones that needed no pop/click editing in PCM, and all of head/tail editing was done in DSD), so running a new set of conversions at 24/88.2 would be easy to do.

 

Thanks again for making me think about this, and I would appreciate any further thoughts you have on the subject.

 

Hook

Hi Hook

 

The NDac supports the 88.2 / 176.4 and even the next one up 352.8 (this higher only from USB-stick).

 

The NDX states it supports up to 24/192 SPDIF and 24/96 UPnP, but it doesn't actually list the intermediate frequencies, so one cannot be absolutely sure of which frequencies are actually supported, unless one of Naim support chimes in or you try some yourself .

 

I would be interested in reading the reason the engineer stated why 96/192 would be easier to process by a DAC than 88.2/176.4.

 

Personally, as a matter of principle, I would prefer to stay with the range of exact multiples and avoid any unneeded interpolations.


-

aleg

Posted on: 03 July 2011 by Simon-in-Suffolk

I would be interested in reading the reason the engineer stated why 96/192 would be easier to process by a DAC than 88.2/176.4.

 

+1

It depends on a lot variables, the DAC chip design ,  the sample frequency of the source etc - ie whther it was an integer mutliple or not etc etc

I think one needs to treat such glib comments carefully. Being an engineer myself and working with and knowing many engineers I can assure you that doesn't stop any of us talking twoddle at times no matter how expierienced and accredited we are.

 

Simon

 

Posted on: 03 July 2011 by Simon-in-Suffolk

BTW - back to the OP topic. I have put a RF choke around the DC1 just as it enters the nDAC from the NDX.

nDAC is on a 555PS with Powerline, the NDX is on Belden 83803. A sublte but delightful improvement is heard in extreme treble clarity.

 

This sweeter high end prompted me to experiment and put back a regular Naim Fraim shelf for the nDAC as opposed the prevoios Lite Fraim which I was using pre choke.

 

The nDAC now truly sings on the full fat Fraim (where as before it was a bit sharp) and significantly the soundstage expands and the depth becomes more apparent (on some recordings).

 

For those tweakers out there - worth a try. Again as always if nothing heard take it off.

I wonder if this affect is similar to using an off board powersupply to power the NDX as a digital front end for the nDAC.

Simon

 

Posted on: 03 July 2011 by AMA
Originally Posted by Simon-in-Suffolk:

BTW - back to the OP topic. I have put a RF choke around the DC1 just as it enters the nDAC from the NDX.

...

 

For those tweakers out there - worth a try. 

Sure -- worth a try.  What particular RF choke did you use?

Posted on: 03 July 2011 by Simon-in-Suffolk

AMA, it was a choke I had in my kit bits and pieces box optimised for for HF (3MHz to 30MHz)  and designed to fit RG213 Coax which is approx 10mm diameter. Look on Google for cable chokes or inductance chokes and you see a broad range- typically from one pound.

Posted on: 03 July 2011 by Hook
Originally Posted by Simon-in-Suffolk:

I would be interested in reading the reason the engineer stated why 96/192 would be easier to process by a DAC than 88.2/176.4.

 

+1

It depends on a lot variables, the DAC chip design ,  the sample frequency of the source etc - ie whther it was an integer mutliple or not etc etc

I think one needs to treat such glib comments carefully. Being an engineer myself and working with and knowing many engineers I can assure you that doesn't stop any of us talking twoddle at times no matter how expierienced and accredited we are.

 

Simon

 

 

Guys -

 

I am trying, but there is a ton of stuff out there on this topic (just google "88.2 versus 96"), and it is easy to get sidetracked.   I recall seeing the Bob Catz article this guy mentions, but now I cannot find it.   I thought this comment was interesting though...

 

http://www.macosxaudio.com/for...viewtopic.php?t=2083

 

"...Now...
About recording at 96khz or 88.2khz... It was believed before that when you went from 48khz to 44.1khz you lost some quality in the sample rate conversion. A lot of people then that weren't sending stuff to any mastering house, and knew that they would have to "master" the project just worked at 44.1. Why record at 48 if you're going to loose it all when you convert it right? So, a lot of people later said that going from 96khz to 44.1 would be the same thing. They said it was better to record at 88.2 because since it's matematically double than 44.1 then there would be a much simpler sample rate conversion... that had a lot less quality loss....

But then... I later read a column somewhere by Mastering Engineer Bob Catz... one of the Digital Audio wizzes in the world which said that sample rate converters had come a very long way. At the end of the article, the main idea was that you gained more from recording at 96khz, than what you lost from sample rate converters. Mr. Catz said that sample rate converters had grown a lot... and not only that; but that a/d converters had gone a long way. So he also said to have it clear that 96khz converters also sound better at 48khz that older 48khz converters... and a 192khz converter sounds even a lot better at 44.1khz than older 48k or even 96k converters..."

 

Yeah, I know this is a different topic -- what rate to record at when the target is CD.   But I think the concept is similar:  the converter math has gotten so good, that grabbing more resolution up front is more important than worrying about interpolation or dithering later.   Catz's article discussed the difference between the chose recording rate and the target (CD).   But wouldn't the argument apply equally well at the next stage (from WAV file to the DAC)?

 

Also, just found this off-hand comment by Kevin Brown (whoever he is) at:

 

http://archive2.avsforum.com/a...ex.php/t-574927.html

 

"...Why 88kHz? I'd go for the full 96 kHz. SACD is 1 bit. Doesn't matter what it's converted to. To 96 kHz and most DACs would have an easier time of it. (No sampling rate conversion....)..."

 

But this is also not the article I saw before, so I'll continue to try and find it later. I am pretty sure it was on gearslutz (nice name), but have just gotten side-tracked on multiple other threads there.

 

Besides, I have now made up my mind to change target resolution to 24/88.1.  The more I read, the more it seems like anything higher in sample rate is pretty questionable.   My golden ear spouse was able to pick 24/192 over 24/96 most of the time, but she did also say that the differences were much more subtle than, say, between the original DSD and 24/192.  The other benefit here is that I don't have to worry anymore about NDX UPnP support for 24/192, and can simply move on....besides, I have a pair of Ovator 400's waiting to be auditioned!

 

Thanks again for the solid advice.   Much appreciated!

 

Hook

 

 

Posted on: 21 July 2011 by Asenna04

Hook,

 

I am eagerly awaiting to hear about your tests between NDX -> nDAC/555PS and NDX/555PS. Did you get around to them yet?

 

As for the Ovators, I am sure you have read again and again, give them plenty of time to run in. Mine sounded awful for first 100 hours and then went up and down for the next 100. Then the magic happened.

 

Enjoy.

 

ASenna04

Posted on: 21 July 2011 by Hook
Originally Posted by Asenna04:

Hook,

 

I am eagerly awaiting to hear about your tests between NDX -> nDAC/555PS and NDX/555PS. Did you get around to them yet?

 

As for the Ovators, I am sure you have read again and again, give them plenty of time to run in. Mine sounded awful for first 100 hours and then went up and down for the next 100. Then the magic happened.

 

Enjoy.

 

ASenna04

 

Hi ASenna04 -

 

The NDX and 400's are both staying.  I decided to keep the NDX as the digital source for my DAC/555PS, but I understand fully now why many prefer the NDX's analog outputs.   And you are right, the 400's did take a lot of time to break-in!   I put a couple of hundred hours on them using Isotek's burn-in disc, and I think that helped a lot.  

 

Anyway, I posted my thoughts (warning -- at length!) in another thread:

 

https://forums.naimaudio.com/di...ent/5650001846489487

 

Thanks!

 

Hook

 

Posted on: 23 July 2011 by Asenna04

Great!

 

Glad to read you liked it. I will read you other post and reply back if I have anything to contribute.

 

ASenna04

Posted on: 03 December 2011 by kingsfan
Does anybody know how a HDX/ Ndac stands in the competition.
I have long gone plans to add a dac to my server/ streamer.

Cheers / Hans
Posted on: 29 May 2012 by ok8888

i wonder if you didnot have got ndac before,you will must buy the nadc as ndx's upgrade?

Posted on: 29 May 2012 by murkku

Not at all.

Some of us decided to sell nDAC after buying NDX.

Posted on: 29 May 2012 by Zinger
In a comparison of: 1. NDX + DAC 2. Bare NDX 3. NDX/XPS.2 + nDAC 4. NDX/XPS.2 5. NDX + nDAC/XPS.2 I liked 5 the most. In fact, that was in my Order of reference (5 being most favorite). So the DAC wasn't entirely an upgrade till a PSU was introduced. However, once the PSU was added to the DAC, the harshness was gone and the better resolution from the DAC was a benefit. But then keep in mind, that setup (#5) has a lot of redundant stuff lying around. That was the "optimal" setup before NDS was introduced. The DAC isn't used on the NDX, and one needs three Powerlines (if one chooses that) and gotta get a proper digital interconnect. The cost of DAC + NDX + extra Powerlines(?) + DC1 would bring the cost very close to that of an NDS. And also to add ... Signals need to run through SPDIF in NDX + dac + psu setup. I would rather go for an NDS for the lower box count, better looks (since DAC is merely slimline case), and 2 fewer power cords to hog up my power strip.
Posted on: 10 March 2013 by LSNYC

Wow...great thread! As a newbie to the Naim family, this was very informative.

 

Currently 2 weeks in to owning a NDX and UnitiServer (in the process of slowly ripping my CD collection) and already thinking about the upgrade options, much learnt from the past 2 hours of reading!

 

On the file format, the UnitiServer is ripping directly to my NAS but is the best definition or should I consider other options when buy new music going forward? If not, will continue to buy CDs and ripping them until the music industry catches up with high def digital music files.

Posted on: 11 March 2013 by GerryMcg

I have bought 24 HiRes albums, just 2 of these being of albums I did not have on CD. In both cases I did not like the album much so a bit of a waste of money. I now buy CD's only to rip and if I like the album, I will buy the HiRes version and sell the CD. In most cases they are clearly superior to the 16/44 version.

 

Gerry

Posted on: 11 March 2013 by Simon-in-Suffolk

Other tfew with a few exception I have found the content on hires downloads just too narrow.

However as I buy CDs to rip and then store, I mostly buy used CDs now where available, and via amazon for example there are thousands of great options from 1p plus (from memory) £1.25 P&P, which is a great way of obtaining quality music.. and of all the 100s of used CDs I have purchased, there has been only one that wouldn't rip, and that was exchanged with no fuss.

Simon

 

Posted on: 11 March 2013 by LSNYC

Thanks Gerry and Simon. Will stick to cheap second hand CD purchases and rip them. Once have stereo system upgraded (looking into per-amp and amp addition) will try hires.

Posted on: 11 March 2013 by mikapoh

Yes I concur that Hi Res download is not as widely available as CDs just yet and the quality of some maybe mediocre depending on its original mastering.

 

Having said this, I have made a direct comparison between CD5XS as transport & Mac Mini playing ripped CD both feeding the same nDAC, the result is not so discernible to my ears.

 

 

Posted on: 13 March 2013 by rca/sun

most high res downloads are far too expppppensive, I bet customers  who buy these downloads they will have cds or vinyl of the same title.