Why is the nDAC so cheap?

quote:

Originally posted by Aleg:
Andy

Then would (nearly) all playback devices be not bit-perfect? This caused by data reading, file conversion into PCM and/or encoding into SPDIF.

Conversion into PCM/SPDIF isn't a bit perfect issue. What is an issue is reading the bits in the first place reliably and error free.

quote:

None of my sources (which aren't so many actualy) sound as good as WAV from USB-stick into nDAC.

I guess it could be a possible cause, all be it a sorry conclusion.

Would there be a possibility to see for a fact that what is being output by an SPDIF encoder is bit-perfect compared to WAV-stored on a USB-stick?

You'd have to capture and compare. Not sure if the M-audio transit USB might be able to do this.

Andy

Andy - just looking back through the thread you've compared your HTPC and a cheap DVD player as the source to the DAC ?

James

quote:

Originally posted by Andy S:

quote:

Originally posted by Aleg:
Andy

Then would (nearly) all playback devices be not bit-perfect? This caused by data reading, file conversion into PCM and/or encoding into SPDIF.

Conversion into PCM/SPDIF isn't a bit perfect issue. What is an issue is reading the bits in the first place reliably and error free.

Andy

Andy

But then it would become quite difficult to explain the difference between the replay of a WAV-file stored on a NAS-harddisk using a mediaplayer and the same WAV stored on a USB stick?
And I can still hear the difference between these two (and no placebo here, really not ) !

So I'm looking where the difference can occur when it can only be a difference in bits received?

Not in reading the file from hard disk, not in converting the file into PCM and also not encoding it into SPDIF, not in the transport through the cable, not in the Naim DAC SPDIF decoder, not in the reclocking by the Naim DAC, not in presenting the bits to the DAC-chip.

What have we left where a difference can occur?

It becomes difficult to apprehend where the difference comes from.

-
aleg

quote:

Originally posted by Aleg:
It becomes difficult to apprehend where the difference comes from.

-
aleg

What, exactly, is your replay chain for stuff that sounds inferior? Just because it is bit perfect on a NAS doesn't mean that either your playback software or the driver for the hardware that outputs it isn't doing some processing.

Unfortunately, the nDAC doesn't have the input sampling rate on it (other than over 48k with the HD LED) so you have no knowledge of what your output chain is doing to the bits before it gets to the DAC.

Andy, I got your point with full respect.

I ran out my words on the subject.
We both have brought some technical arguments and both agree to disagree with each other.

I can summarize your viewpoint as following:
1. nDAC rejects all the jitter on SPDIF
2. All people who hear a difference in transports/cables are cheated by placebo effect.

I summarize my viewpoint as:
1. nDAC rejects the jitter partially and may reject it completely if it goes below threshold in the income bitstream -- which is not the case for modern transports
2. many people hear the difference in transports in CLEAN blind test because modern transports still have high value of total jitter and different jitter spectrum which still penetrate partially through nDAC

To make it clear from my point of view the modern high quality transports already sound very close to each other at least if we compare it to the differences in amplification and speakers. I don't think it's practical to go into a big discussion on this point once we still have so many findings to share on much more audible elements of our systems.

I think it's a good point to stop over.

Let's enjoy music!!!

quote:

Originally posted by AMA:
I think it's a good point to stop over.

Let's enjoy music!!!

Yup. Happy to do that

Andy

The diagram below shows the digital output of one of my CD players. What does IC 74HCT08 do? Is it a buffer?

quote:

Originally posted by Andy S:

quote:

Originally posted by Aleg:
It becomes difficult to apprehend where the difference comes from.

-
aleg

What, exactly, is your replay chain for stuff that sounds inferior? Just because it is bit perfect on a NAS doesn't mean that either your playback software or the driver for the hardware that outputs it isn't doing some processing.

Unfortunately, the nDAC doesn't have the input sampling rate on it (other than over 48k with the HD LED) so you have no knowledge of what your output chain is doing to the bits before it gets to the DAC.

At the moment I mostly use mpd on a Popcorn Hour in combination with a NAS based on Ubuntu Server.
For the Popcorn I use a plugin that writes the data received from the CODEC used in the mpd player directly into the memory of the Sigma Designs SMP8635 chipset from the Popcorn (I have the source code for the plugin and can see there is no processing in the plugin) there is also no mixer, no volume control, no resampling or any other processing taking place within mpd, all these features have been turned off. The plugin has been specifically developed for use with this Syabas chipset and doesn't use any Linux drivers, so no ALSA or anything like that, just directly into the chipset.

MPD has been confirmed to be bit-perfect when used with ALSA drivers and since I don't use ALSA, the mpd player also has to be bit-perfect and I can see in the source code of the plugin that no procssing of the bits takes place, so that also still has to be bit perfect.

The Sigma Designs SMP8635 chipset outputs this data unchanged to the coax SPDIF output, others who can check the output sampling rate have confirmed this fact that the sampling rate remains unchanged.

Another sources that I have used and which sounds less good than a USB-stick is the Naim CD5-XS connected to the Naim DAC. Maybe the CD-mechanism is less then optimal?

Does this give you any information to further comment on regarding NAS-playback?

-
aleg

quote:

Originally posted by Andy S:
Who is splitting up What I do is rip the whole to a single FLAC file. EAC generates a .cue sheet with it (see below) which my htpc software reads and presents me with the track listing. Clicking on the track the software jumps to that point in the file and begins playing from there.

Sorry, I assumed you were splitting into individual tracks, a la a vinyl transfer.

To each their own. I create cue sheets only for the purposes of burning. I dont play from cue sheets.

I assume that you cannot listen to individual tracks this way????

In any case, I would seriously set-up EAC again per the guide I linked to above.

But I am going to guess that you assume you know best so forget I offered help.

-patrick

PS - EAC has perfect gap detection (as well as pregap tracks), not sure what you meant there. I guess It would make sense if you used a media player that did not support gapless playback.

isnt it known that jitter is not the sole reason for different SQ between transports, CDPs, PCs, and cables etc...???

Or am i wrong here?

If jitter is everything then why would the 555 CDP have higer jitter measurements than many other inferior sounding players?

-patrick

quote:

Originally posted by fatcat:
Andy

The diagram below shows the digital output of one of my CD players. What does IC 74HCT08 do? Is it a buffer?

Looks like it's acting as a buffer (3 in parallel) plus a gate. The signal at the top of the diagram (can't read it - is it A105-1?) will allow the signal through if it is high - will be nothing if that input is low (perhaps a digital output switch??). If it isn't, nothing out of the A107(??)-1 pin nearly at the bottom.

quote:

Originally posted by pcstockton:
isnt it known that jitter is not the sole reason for different SQ between transports, CDPs, PCs, and cables etc...???

Or am i wrong here?

Oh no... Jitter is but one component. What jitter says is that given the SAME DAC setup, the higher the jitter, the worse the sound is. You can have good DAC setups and bad ones...

quote:

If jitter is everything then why would the 555 CDP have higer jitter measurements than many other inferior sounding players?

-patrick

DAC configuration.... It's not all about jitter...

quote:

Originally posted by Aleg:
aleg

Man.. you've investigated your replay chain more than I have... !! All I can say is I tried 44.1/16 and 24/96 off a USB stick today as well as directly off my streamer. What surprises me is I can't hear any difference between the sources, yet I CAN hear differences between the cables I'm using... And not in a "good" way. I've been playing the nDAC through a very cheap cable that goes into my 52... To me, that sounds more "alive" than the SNAIC supplied with the nDAC. I've only tried it the first time today and I'm still unsure, but it sounds to me like the SNAIC is slow but rounded verses the cheapo interconnect which sounds clearer and more direct. Perhaps this will be smoothed by a power supply upgrade... What's more the difference is immediately apparent to me.

Why do I mention this? Merely to say my expectation when I used the SNAIC would be that it sounded better. Having used it, I'm not sure. It will take a few days to find out. Why am I saying this: well, because I was expecting transports to make no difference, yet I was expecting cables to. My findings: transports are no different to me, cables are, but in the opposite way to my expectations. Make of that what you will

quote:

Looks like it's acting as a buffer (3 in parallel) plus a gate

and using the 3 gates in parallel is a cheap way of increasing the output current to drive the pulse transformer used on the coaxial SPDIF output.

quote:

Originally posted by james n:

quote:

Looks like it's acting as a buffer (3 in parallel) plus a gate

and using the 3 gates in parallel is a cheap way of increasing the output current to drive the pulse transformer used on the coaxial SPDIF output.

James

Would the quality/accuracy of the data leaving the IC be dependent on the quality of the power supply feeding pin 14, given the use of a decoupling and bypass cap.

This circuit was used in a mid priced CD player. Presumably a high end player would use an expensive/better method of providing current. Perhaps this would have an effect on sound quality

quote:

Originally posted by james n:

quote:

Looks like it's acting as a buffer (3 in parallel) plus a gate

and using the 3 gates in parallel is a cheap way of increasing the output current to drive the pulse transformer used on the coaxial SPDIF output.

Yup.. could be...

quote:

Originally posted by fatcat:
James

Would the quality/accuracy of the data leaving the IC be dependent on the quality of the power supply feeding pin 14, given the use of a decoupling and bypass cap.

This circuit was used in a mid priced CD player. Presumably a high end player would use an expensive/better method of providing current. Perhaps this would have an effect on sound quality

Not James but...

I can't see the circuit in detail, let alone in context with what's around it. What's the question you are asking?

quote:

Originally posted by Joe Bibb:

quote:

Originally posted by ROTF:
That's because many evangelised DACs really weren't very good - that has all changed with some great sounding DACs from Naim and Chord.

Can't agree. There are several fine DACs around and a PC or Mac properly set up for audio is better than any transport I've heard so far, including the ones referred to by Richard, good as those old Meridians are (I have two). You may wish it to be otherwise or disagree and that's fine, but please don't state opinion as fact.

Joe

It is opinion, of course, but one highly evangelised DAC sounded so poor to me that I couldn't believe people could ever tolerate it; others who auditioned it at the same time as me did not think it lived up to the hype either, so I was not completely alone. Yet some seem to state as fact that this was a ground breaking product. So I apologise if it seemed I was asserting my findings were definitive when it was my opinion. We disagree no more than that - I don't really wish one product to be better than another, I just hear what I hear.

Still that is old news. The latest generation of DACs from Naim and Chord sound very much better to me and really play music as well as any CD player. I think often when people make a technology switch then they like to evangelise rather than say whoops I made a mistake - makes them feel better (happens a lot with Computers). However, I think we agree the Naim nDAC is a huge step forward from what we had a year or so ago. What I hadn't found was the right transport for me: I knew it was not a general purpose computer, as the sound just seemed to shrill for me - though Chord seems to have solved this. However, it is a Naim nDAC that I wish to use in my system rather than mix and match, so I needed to find the right transport.

It is interesting that many agree than a USB stick gives far better results than a Mac used as a transport. It certainly did in the audition I heard. My guess is it is the quality of the S/PDIF interface and the OS clutter that holds the Mac back - of course, this can be improved as Chord's clever BT interface does. Still for me, it is great news as a superb USB transport will cost me less than the price of a CD.

So I have the answer - the transport of choice for me is a humble USB stick.

To re-iterate this is only a point of view - everybody should choose what suits them.

Richard's thread is very interesting - be interested to hear Richard compare a USB stick to an expensive transport.

ATB Rotf

quote:

...So I have the answer - the transport of choice for me is a humble USB stick.

any particular make you fond that worked well with nDAC?

enjoy
ken

ok,ok,ok..... just a second. To address the OP's Thread title..... $3500 is "cheap"?

Get some perspective. I am guessing .001% of the world can afford that and far fewer would spend it on a DAC.

quote:

Originally posted by ROTF:
be interested to hear Richard compare a USB stick to an expensive transport.

ATB Rotf

Yes, as well as the M-audio Transit (mentioned in the DAC White Paper), and some of the the Naim sources with digital output.

-patrick

quote:

Originally posted by ken c:

quote:

...So I have the answer - the transport of choice for me is a humble USB stick.

any particular make you fond that worked well with nDAC?

enjoy
ken

The SanDisk Cruzer works very well.

quote:

Originally posted by pcstockton:
ok,ok,ok..... just a second. To address the OP's Thread title..... $3500 is "cheap"?

Get some perspective. I am guessing .001% of the world can afford that and far fewer would spend it on a DAC.

Yes, it's cheap compared to other Naim products. Firstly it's £2000 here in the UK and I have a friend who is selling his CDS3 front end as he thinks the difference is so minimal to be worth both the convenience factor and the extra money he'll get back from selling the CDS3 second hand (can't remember how old it is but he bought it second hand 18 months ago so probably 3+ years old).

Additionally, you can feed up to 8 digital inputs into it so you benefit that way. I'm still stereo here - no want or need or ability to afford!! surround when you have DBLs It definitely improves the TV and htpc and I'm looking at a hi-def terrestrial box to wire into it too - in fact, if it had power amps out and a volume control, I'd probably sell the 52.... so for me, even though I haven't spent serious money on my Naim system for 10 years, I consider it very cheap

PS. Downloaded some 44.1/16 and 96/24 stuff yesterday. Have a difficulty telling the two apart, but could tell the difference - just.

Tried the two samples USB vs optical through the HTPC and couldn't tell any difference. I'm coming to the conclusion the DAC is pretty much source independant for me. Now some possible thoughts come to mind:

- Placebo effect (I'm expecting the sources to sound the same so they do)
- There is no difference between sources (my current thought)
- My system has so little resolving power to make all differences negligible
- My hearing is so bad to not notice any.

I'm kinda discounting the last two options as changing the cables (from a £4 RCA->DIN cheap job to Naim SNAIC) did make a difference - but not in the way I expected it to (which leads me to discount the Placebo effect too). The difference was immediate and noticeable within the first few seconds of the song.

quote:

Originally posted by Andy S:
I'm still stereo here - no want or need or ability to afford!! surround when you have DBLs It definitely improves the TV and htpc and I'm looking at a hi-def terrestrial box to wire into it too

Well, I have said the same for many years, playing my TV sound through a good stereo system, but I'm afraid that the arrival of HD and Blu-Ray has changed things for me. Having tried it, I now believe that a centre channel is neccessary as a minimum. In fact, I have just gone for a complete 5.1 package, not for dramatic sound effects, but because it makes general viewing far less fatiguing than listening to the sound converted to stereo and played through speakers either side of the screen.
I have moved my music system to the other end of the room, although I'm sure the presence of the surround speakers will be polluting the music with their passive movements when the hifi is on. Didn't Linn used to claim that a telephone in the room could destroy the tunes?