NDX and Chord Hugo

The Lunar uses the same WBT RCAs as on the HiLine. An excellent cable which combines the transparency and fluidity of the HiLine with the verve of the Lavender (and is a lot more robust too). 

Thanks for the info Simon.  Now I can finally order my Hugo.

Going back to the SQ of the Naim DACs versus the Hugo I am wondering if there is any possibility of further tweaks by Naim to the firmware upgradable products such as NDS.

I revisited the NDS appreciation thread today and certain members report noticing a SQ change for the better following some of the FW updates.  I understand the DSP code is re-flashed as part of the update.  I am not suggesting they should tweak it to sound like the Hugo as I have not heard the Hugo yet but do the more digital savvy out there consider it’s a possibility.

Has anyone actually done an NDS/555PS @ £13,000 vs NDX/HUGO @ £5,000 comparison?

I'm finding it difficult to see how much better it can get than the latter it's sounding so damn good!

G

Also has anyone done a NDS/555PSDR versus NDS/555PSDR with Hugo as the output DAC instead of the NDS internal DAC.

@ Cloth Ears, I have experienced subtle sonic changes in the past with firmware changes with the NDX and noticed it once with a borrowed NDS.

I suspect the sound differences one hears between the current Naim products and the Hugo is more architectural related rather than tweaking changes in the execution timing or sequencing of the DSP code in the Naim digital filter.

I think Naim use an IIR convolution filter as opposed to an FIR which I believe is used in the Hugo, but that in itself is probably of little sonic impact, I suspect however with the current Naim architecture / hardware it's not possible for Naim to increase the accuracy of the filter without running out of processing capacity, or by causing too much power drain and all the associated problems and interference associated with that.

But I am sure Naim are not resting on their laurels and are / will be  looking at the innovations in this space and might be experimenting with new low power FPGA/ micro controllers that have only relatively recently become available and have the ability to perform more accurate reconstruction filtering with minimal artefacts using low power.

Simon

I haven't myself, but I have listened to a NDX and NDX/555PS feeding a Hugo.. There was a slight sonic difference between the two, but I couldn't say one was preferable to the other. In the end I have opted for a single NDX with Powerline to feed the Hugo...  and jolly good it is too... 

Thanks Simon for both replies.

Great review in Hifi Choice including "viva la revolution" opinion piece , as always the forum was one step ahead . 

There certainly have been changes to NDS performance after FW updates and since this process also reflashes the DSP it is not surprising, although I haven't always detected changes and sometimes those I have were not for the better - to my ears. I don't have a crystal ball but it strikes me as logical to suppose that what with all the other development work going on market wide, DSP tweaks, room matching and speaker optimisation will be part of FW development to some extent on current streamers and to an increasing extent on future DACs and streamers. This stuff is getting to be more incorporated into standard feature sets and Naim won't park themselves in a side street. Although they will not fiddle just for the sake of it and their output will be steady (AKA slow) conservative but effective.

In the opinion of the reviewer it's a V1 beater. I accept the highly subjective nature of this (covered already in some depth) but the comparison point is interesting. Was the V1 cited on performance or its price point.

I see they also have an NDS/555PS on evaluation. I wonder what  they'll make of that?

The review was nice enough but I thought the opinion column was not that well written and poorly argued.

Well remembered. A DAC or a DAC-Pre in smaller form factor. The V1 delivered the latter but not at the high-end. We said progress would do well if it delivered both better SQ and miniaturisation. The Sony Walkman being one example. If memory serves this was scoffed at by large box collectors.

As ever, there seems to be too much focus on DSP, DSD, FPGA and other frippery.

The major differentiating factor in SQ of a decently implemented DAC in this day and age is the analogue section. The Naim DAC uses a similar one to CDS3 and NDS I believe.

What does the Hugo offer in the analogue section?

What I retain from reading the designer's views is that the digital filtering accounts for a substantial part of the Hugo's naturalness. The analog section is quite simple, apparently. There are some explanations by Rob Watts on the Head Fi Hugo thread. If I find time, I'll locate them, or perhaps Hook has bookmarked them ?

Mark, see section 3 below, from Rob Watts (on the HeadFi forum) :

1. The interpolation filter is key to recreating the amplitude and timing of the original recording. We know the ear/brain can resolve 4uS of timing - that is 250 kHz sampling rate. To recreate the original timing and amplitude perfectly, you need infinite tap lengths FIR filters. That is a mathematical certainty. Hugo has the largest tap length by far of any other production DAC available at any price.

2. RF noise has a major influence in sound quality, and digital DAC's create a lot of noise. Hugo has the most efficient digital filtering of any other production DAC - it filters with a 3 stage filter at 2048 FS. The noise shapers run at 104 MHz, some 20 times faster than all other DAC's (excepting my previous designs). What does this mean? RF noise at 1 MHz is 1000 times lower than all other DAC's, so noise floor modulation effects are dramatically reduced, giving a much smoother and morenatural sound quality.

3. The lack of DAC RF OP noise means that the analogue section can be made radically simpler as the analogue filter requirements are smaller. Now in analogue terms, making it simpler, with everything else being constant, gives more transparency. You really can hear every solder joint, every passive component, and every active stage. Now Hugo has a single active stage - a very high performance op-amp with a discrete op-stage as a hybrid with a single global feedback path. This arrangement means that you have a single active stage, two resistors and two capacitors in the direct signal path -  and that is it. Note: there is no headphonedrive. Normal high performance DAC's have 3 op-amp stages, followed by a separate headphone amp. So to conclude - Hugo's analogue path is not a simple couple of op-amps chucked together, it is fundamentally simpler than all other headphone amp solutions.

This brings me on to my biggest annoyance - the claim that Hugo's amp is merely good. Firstly, no body can possibly know how good the headphone amp in Hugo is, because there is not a separate headphone stage as such - its integrated into the DAC function directly. You can't remove the sound of the headphone amp from the sound of the DAC, it's one and the same.

Watts from Post 3293...

In a conventional high performance DAC you have two I/V converters, a differential to SE converter, then a headphone OP stage. That means the signal has to pass through 4 active stages, plus a lot of passive components to do the filtering.

With Hugo there is only one active stage - an I/V converter, which just happens to have a high power discrete OP stage. Also, because Hugo does a huge amount of oversampling (2048 times) and filters the noise digitally, and because pulse array DAC also has innately low out of band noise, then the RF filtering can be simple. So passive components in the direct signal path is two caps and two resistors.

So the whole analogue chain direct signal path is only 4 passive components and a single active stage. That's it. And its one reason why Hugo is so transparent....And why there is only one OP feeding 4 connectors. 

...but who's counting?  

ATB.

Hook

And of course how big is its power supply?

Power supply is where its at.

Everything else is frippery.

Ok.

I don't get why some are over interested in what is inside Hugo or any other product for that matter. Two products can contain the same chip yet sound totally different, i presume due to its implementation.

Surely all that matters is the SQ it produces. Ive never bought or rejected an item because it did or didn't have a certain chip or whatever in it.

Facilities or functions, yes for sure

Graeme

After 14 pages talking about the Hugo's custom dac chip and how it is different from using the usual off the shelf dac packages , our Mr Wahlberg here still thinks that..

The major differentiating factor in SQ of a decently DAC in this day and age is in the analogue section.

I think this statement is kind of my point. How can you know if its the chip the output stage or any other single item that makes the Hugo sound as good as it does. You can't remove an individual section to be able to test it.

So therefore what does it matter. I'm sure Mr Watts knows, or maybe he just got lucky.

Graeme

In the case of the standard, "off-the-shelf" DAC chips used in the vast majority of DACs that's probably the case.