Naim DAC with external PS

Christ mate let the product get out there first.

Haha, naim must love this forum.

quote:

Originally posted by AllenB:
Whether the product is out there or not, the 555PS makes a HUGE difference to the Naim DAC.

Nothing really to do with the DAC, it's the output stages when talking of power supplies.

Not true. The digital PS's do more. Runs the DAC portion + analog on the HDX and does a few sections on the DAC if I recall correctly.

Oh my! Follow the wires.

As you should but what does that have to do with what portion the external supply powers? I never mentioned sound in my post. If you're saying the PS makes significant difference, then we're actually in total agreement. I was just referring to it not being only an analog supply. I think this may be more of a communication break down than a disagreement.

Really, and is that why a CDX2 gets unplugged from the mains when a supply is added?

You mentioned the CDPs. Not me. The digital signal processing supply is being kept away from DAC and analog in the other 2. There are voltages being delivered and used here that have nothing to do with the analog section or we'd be talking about a SC and Hicap instead as with a CD5x that is supplimented in the analog only. As long as it works I guess. I really didn't intend to offend. Just some info.

No point. Just corrected function info. Like I said. No offense intended and I am in no way challenging your ears.

Allen, I completely agree that the supply is a waste on the HDX when used as a source for the DAC. This from the white paper shows that there's more to what the outboard supply does than the analog. You'll notice that it powers the clock, DAC chips, I2V converters, analogue filters and main output .

"The (inboard) transformer has three isolated windings, feeding three sets of rectifiers and reservoir capacitors: one for the DSP, one for the clock circuits and the last for the DAC chips, I2V converters and analogue filters.
When the PSU upgrade option is used with the Naim DAC, power supply separation is further increased by the use of a dedicated supply for the master clock circuits. It also provides a bigger toroidal transformer and bigger reservoir capacitors, and the DSP remains powered from the Naim DAC transformer to give even more separation from the analogue section."

When used on an HDX.
"This is done so that all the external supplies are best utilised for powering the various digital circuits. In this mode the pre-regulators for the DAC digital and the de-jittering circuits are fed by the external supply and therefore triple regulated."

There's a diagram that shows the external supply taking over 12 circuit blocks while the inboard retains 3. http://www.naim-audio.com/down...%20Disk%20Player.pdf This may now be unimportant as the DAC is now the preferred path but I wanted some clarity of purpose.

Again, I don't disagree with your assessment of the combo or recommendation in any way. I suspect that you got an over simplified overview from another and thought I may be embelishing. I'm not. Just trying to make clear what these outboard supplies actually do for those like the OP that asked. Please, do not take offense.

quote:

Originally posted by js:
Allen, I completely agree that the supply is a waste on the HDX when used as a source for the DAC.

...

When used on an HDX.
"This is done so that all the external supplies are best utilised for powering the various digital circuits. In this mode the pre-regulators for the DAC digital and the de-jittering circuits are fed by the external supply and therefore triple regulated."

There's a diagram that shows the external supply taking over 12 circuit blocks while the inboard retains 3. http://www.naim-audio.com/down...%20Disk%20Player.pdf This may now be unimportant as the DAC is now the preferred path but I wanted some clarity of purpose.

If I understood that diagram correctly the external PSU, when used on the HDX powers the DAC and clock circuits. Now, when feeding the external DAC, the internal is, of course, not used, but giving the clock a better regulated power source might be an improvement. Regardless of how powerful the de-jitter in the Naim DAC is, it should always work better if the incoming data stream is cleaner and with less jitter.

So, I wouldn't say "a complete waste". I would, for now, stick to "it might help, but probably not a lot".

quote:

Originally posted by nkrgovic:

Regardless of how powerful the de-jitter in the Naim DAC is, it should always work better if the incoming data stream is cleaner and with less jitter.

Why?

quote:

Originally posted by likesmusic:

quote:

Originally posted by nkrgovic:

Regardless of how powerful the de-jitter in the Naim DAC is, it should always work better if the incoming data stream is cleaner and with less jitter.

Why?

This topic has been the source (no pun intended) of much debate and argument on the forum for quite some time and has escalated as we get closer to the release of the DAC.

There are believers in the various components which have an end effect on the Audio quality and those who don't.''This article nicely goes through alot of the questions which are brought up here repeatedly and MAY help to clarify some issues.

It's worth the read.

http://www.positive-feedback.com/Issue43/jitter.htm

I have read that article, and my question still stands.

The article states that there are several types of re-clocker. The NAIM Dac is what the article calls a 'true re-clocker' which, " can deliver the lowest jitter of the three types because it is not influenced by any outside signals.

Not influenced by any outside signals.

The NAIM Dac buffers and re-clocks the incoming data stream, so it is not influenced by jitter in the incoming data stream providing the buffer doesn't over or underflow.

My question stands: How can the Naim DAC be influenced by the power supply of the HDX?

quote:

Originally posted by nkrgovic:

quote:

Originally posted by js:
Allen, I completely agree that the supply is a waste on the HDX when used as a source for the DAC.

...

When used on an HDX.
"This is done so that all the external supplies are best utilised for powering the various digital circuits. In this mode the pre-regulators for the DAC digital and the de-jittering circuits are fed by the external supply and therefore triple regulated."

There's a diagram that shows the external supply taking over 12 circuit blocks while the inboard retains 3. http://www.naim-audio.com/down...%20Disk%20Player.pdf This may now be unimportant as the DAC is now the preferred path but I wanted some clarity of purpose.

If I understood that diagram correctly the external PSU, when used on the HDX powers the DAC and clock circuits. Now, when feeding the external DAC, the internal is, of course, not used, but giving the clock a better regulated power source might be an improvement. Regardless of how powerful the de-jitter in the Naim DAC is, it should always work better if the incoming data stream is cleaner and with less jitter.

So, I wouldn't say "a complete waste". I would, for now, stick to "it might help, but probably not a lot".

I believe that the dig out of the HDX is seperate from the internal and not effected by the outboard PS. If you look at the sources used on an HDX it can be relatively low jitter if carefully designed even before jitter correction. I suspect the dig out is good jitter wise but not reclocked and with low noise so it's a great match for the DAC. The internal DAC has it's own jitter solutions when required as does the seperate Naim DAC. It should come as no surprise that these 2 bits of kit would match up well. I understand your Clock/PS comment and believe this portion does help on the outboard DAC also but I don't think it's in the mix at the HDX DIG out which is software based. Not an engineer and just trying to understand some of this myself without all the info but I can assure you that the dig out is functional with no PS or jumper plug attached. This could also add to somes confusion of the outboard PS's purpose in these pieces in general. Auditions like Allen and I have done show pretty clearly that a HDX outboard PS is of no benefit when used as a dig source with the Naim DAC. Of course no one already owns 2 and they're great when moved over to the DAC.

quote:

The NAIM Dac buffers and re-clocks the incoming data stream, so it is not influenced by jitter in the incoming data stream providing the buffer doesn't over or underflow.

likesmusic, Naim DAC can not guarantee to reject all the input jitter as well as no other DAC in the world can do this.
As a minimum Naim DAC guarantee that it will almost not ADD the jitter to the input bitstream.
Besides it will work hard to reject a significant part of the income jitter -- it concerns those bits which are not seriously delayed to arrive to the Naim DAC on time. But if income bitstream has some specific jitter which results in some bits periodically are delayed in time -- then these bits can be misinterpreted on the S/PDIF receiver in Naim DAC as arrived in time (which is a wrong time for this particular bit). Naim DAC will not be able to understand this and will put the received bit in the buffer as if it arrives in a good time which is a mistake.
This is how input jitter can penetrate to the output of ANY re-clocking circuitry. It's all happens on the S/PDIF receiver.
Of course if input jitter is small enough so that none of the bits arrive to Naim DAC ridiculously out of time -- then Naim DAC will carefully capture the bits, identify their timing and send them to buffer in the right order -- thus completely eliminating the input jitter.

This is just a theoretical note: regarding your very question on HDX I have no idea of how good is the output jitter on HDX S/PDIF and is it affected by external PSU. I can only speculate (as a true believer of Naim superior designs and blind believer in that 8 K$ source can not be high jitter ) that bare HDX output jitter is low enough to be properly captured by Naim DAC. So there possibly no need to hook up a crazy PSU on HDX in order to further improve on jitter -- though it may help in case you run HDX into a non-reclocking DAC (which most naimophiles will probably never do). Of course, a high quality PSU on DAC is supposed to be a MUST -- both for super-fine clocking and output gain stage.

I can only say that currently Klimax DS sounds much more open and detailed for me than HDX through it's built-in DAC.
We'll see if Naim DAC improve on this.

That interpretation seems right to me. I also don't expect the output jitter of an HDX to be of an ultimately low nature but low enough and of a type that is condusive to the DAC. I do expect it to be, both stream and electrically, almost noise free. It shouldn't surprise anyone that they would make a cohesive package.

AMA, are you saying that the HDX can transmit incorrect bits to the DAC? Or that the DAC will pick them up incorrectly? How do you know this? It would be a major disaster if either were the case.

quote:

Besides it will work hard to reject a significant part of the income jitter -- it concerns those bits which are not seriously delayed to arrive to the Naim DAC on time. But if income bitstream has some specific jitter which results in some bits periodically are delayed in time -- then these bits can be misinterpreted on the S/PDIF receiver in Naim DAC as arrived in time (which is a wrong time for this particular bit). Naim DAC will not be able to understand this and will put the received bit in the buffer as if it arrives in a good time which is a mistake.
This is how input jitter can penetrate to the output of ANY re-clocking circuitry. It's all happens on the S/PDIF receiver.
Of course if input jitter is small enough so that none of the bits arrive to Naim DAC ridiculously out of time -- then Naim DAC will carefully capture the bits, identify their timing and send them to buffer in the right order -- thus completely eliminating the input jitter.

Lost in translation, methinks–interface jitter is less about bits not arriving in queue out of order, but not in exact time.

quote:

Originally posted by likesmusic:
AMA, are you saying that the HDX can transmit incorrect bits to the DAC?

Yes, likesmusic, all S/DIF out devices send spoiled, contaminated jitter abound bitstream.
Poor devices have high intrinsic jitter inside the box before even reaching the S/DIF out generator.
Good devices have low intrinsic jitter but when reach S/PDIF out they are modulated with S/PDIF jitter.
The bits are not affected as data: I mean one's are not mistalken with zero's.
But the timing of bits can be very wrong. If you donlt pushh me hard to analyze a bitstream on-line then I can carefully capture all bits and in case a check-sum is not OK I can suspend reception and re-read a part of the bitstream and verify all bits are captured properly. This how PC reads a CD-ROM and alwys secure it retrieved the data from CD-ROM bit-perfectly. The price to pay -- one never knows how LONG it will take to repeat the iterations and complete the transmission. In audio streaming we have no time for such iterations.
We have to analyze the bitstream in real-time. We are given a fixed time-limit and we have to identify the bits in the next data portion and save them to a buffer. This is a challenge.

A perfect digital bitstream is a sequence of bits which travel in a due order, each bit occupies exactly the same time. There will be no problem to decode such a bitstream. In real life the source bitstream is not perfectly timed which results in various time delay/overrun of bits -- which is called JITTER. It's not just an even shift in time -- it's spontaneous and have a complicated structure called JITTER SPECTRUM. The actual jitter spectrum is defined by a source design including clock quality and S/PDIF output contamination.

quote:

Or that the DAC will pick them up incorrectly?

I'll try to put it in a simple way (although a real picture is a bit more complicated).
HDX pushes out a jittered bitstream where some bits can delay/overrun in time. There is no mistakes in bits themselves -- zero's are not interpreted as one's in a bitstream itself. The problem is that if your source has a high jitter then DAC expects for the next bit to come at 11:00 but due to the spontaneous delay of this particular bit it will come at 11:02. But DAC clock does not understand this and carefully wait for this bit to arrive at 11:00 or (being a smart S/PDIF receiver) it can wait until 11:01, but noway until 11:02 because 11:02 is scheduled for the next data portion. If jitter is high so that slow bit was seriously delayed the 11:00 -- 11:01 will be marked by DAC as zero and sent to buffer which can be OK but can be mistake -- with 50% probability. Imagine that happens thousands times per second and you can imagine the possible accumulation of these mistakes resulting in serious sound deterioration.

quote:

How do you know this?

If you mean how do I know that HDX has a jitter -- I can tell you that HDX sound is not that refined to my ears as Klimax DS which mostly relates to a higher jitter.
If you mean how do I know that Naim DAC picks some bits incorrectly -- I can tell you that this has nothing to do with Naim DAC as such -- if source jitter is high and bits are seriously out-of-time then none of the DAC in the world will be able to decode them.

quote:

It would be a major disaster if either were the case.

Yes, likesmusic, jitter IS a disaster and CD players which can go really down in jitter are usually having a very high price tag > 10 K$. I believe that recent boom in streamers will resolve this problem and low jitter streamers will be soon available at regular cost. For example, Logitech Transporter has very low output jitter and when feed to re-clocking DAC like Lavry result in almost jitter-free playback. The brand name CD player with similar jitter will possibly cost > 10 K$.

There's more to the sound of these things than just jitter differences. I wouldn't assume an HDX has more or less jitter than a DS regardless of which sound is preferred by a given individual. May or may not be the case but DAC types, filter circuits and analog stages also have a significant overall effect on the sonics. Some of what's heard before a PS is added may be jitter but once a XPS is added to an HDX's internal clock circuit, I doubt jitter is any longer an issue when used less DAC. One maker may trade some boogie for refinement or vice/versa leading to individual preferences beyond jitter. Certain types of jitter can actually be euphonic to some interpretations. If you've ever played with a DAC that had selecable filter types you'd see how much things can change with the same jitter content and audible band frequency response. Not comparing the sound of these 2 as I haven't directly done so but I wouldn't attribute any particular characteristic directly to jitter.

js, I did a lot of experiments with both digital and analogue filters.

Analogue filters don't affect sound resolution and only change sound presentation. This is a domain where speed is usually compromised with ultimate linearity. This is the place where Naim and Linn CDPs are forming the biggest sound differentiation.

The digital filters can theoretically affect resolution but I doubt that someone applies detrimental filters on the incoming bitstream. The simplest filter you can think of today is upsampling.
It handles a jitter partially resulting in better resolution but has it's own downsides such as adding some artificial elements to the sound.

The input filter mathematics is mostly focused on achieving a time-smoothness WITHOUT giving up a resolution. With different success at different brand names.

The sound of Klimax DS is more open, spacious, more microdetails, better imaging than bare HDX-- it looks like much better jitter handling. It's difficult to explain by that Linn has elaborated super-mathematics or HDX is using detrimental digital filters.

The average peak-to-peak may be a very poor guide of jitter contamination. If jitter is above 350 ps the sound will definitely be BAD with no chance for re-clocking DAC to handle it completely. If jitter is low at say around 200 ps -- but since jitter spectrum is different two gears can sound very differently.

CD5X peak-to-peak jitter measures even better than CD555

js, you're playing around with Naim DAC.
I see you are mostly focused on drivers settings and various software players.

Why don't you test it against the other gears sonically -- or make up an audio session for your customers?

quote:

The bits are not affected as data: I mean one's are not mistalken with zero's.

In which case what difference can a better power-supply for the HDX make?

I can't see how jitter is relevant - as long as it is reasonably low the buffering should render it irrelevant - isn't that the whole point of the design?

Because I only had it for a day+. I don't focus on players and tried because it was asked and discussed here, mostly after the DAC was gone. Less than 1 hour was used listening to players through the DAC. The rest was putting it through it's paces with familiar material vs the best DAC we've heard before this and source comparisons. I have both a 555 and HDX on display along with Nagra bits so I have fine comparitors. Others here have preferred the HDX with PS to the DS so it's all somewhat relative. I haven't compared directly so have no opinion but I do know very early HDXs weren't as good until updated and that the refinement factor increases significantly with outboard supply. Some of this may be jitter related and some not. I would expect the raw performance of somethong 2.5 times the price to have something on a HDX but I wouldn't think it jitter once the Clock is reinforced with an outboard PS. I'm also not disputing what you heard, especially if we're talking raw HDX but I would think adding a PS would be more fair. Source rips etc. can also play a role. There's lots of variables that can work for or against any dem. You obviously prefer the DS to HDX, may do so with or without supply, and that's great but attributing that preference to mostly jitter seems strong to me. I do however, appreciate your perspective in general. Your Kung Foo is strong.

I prefer the Nagras but I already use a TC for computer audio which is in effect the same input as Weiss use so my perspective may be somewhat skewed. The VI is clearly better than the LB but the LB is still very good. Has that open, very slightly softer and sweet character that many love. The VI is tighter, solid and more insightful with correct space. I do like the Weiss overall but as a firewire computer DAC. It's a nice all in one solution for that segment though as a SPdif DAC it's good but not special. Much easier to use as a DAC than the Nagras are as they're more than that but then again, the Nagras are an exceptional tool for tranfering analog to digital. They can also play attached storage directly though the interface wouldn't please many. Much depends on use and and need. Looking forward to the Weiss INT202 for a straight forward consumer freindly interface. Haven't heard Amarra but I like the concept and trust those that like it as they were mostly of an opinion that players and path don't matter before trying it.

So did hearing the Naim DAC make the waiting easier or more difficult?

quote:

Because I only had it for a day+.

Ooops. Now it's clear. OK -- let's keep waiting.