Comparisons with HDX, UnitiServe, nDAC, 555PS and NDX in an audiophile environment
Posted by: aysil on 16 January 2011
I’ve been an audiophile enthusiast for more than 20 years, and during the last years, I was lucky to be able to enjoy an ultra-neutral and ultra-transparent system. Lately, I was again attracted to equipment of Naim, a brand I always admired very much, because they seemed to suggest a way of introducing new formats to our music system without being dependent on a turned on computer. I decided to purchase HDX, UnitiServe, nDAC, 555PS and NDX (has not arrived yet) to do some experimentation. I am new to this forum, but I spent days and many hours reading the many discussions, and I decided I could share my impressions:
I started by ripping some of my CDs to the on-board hard-drives of HDX and UnitiServe and gave all devices around 300 hours burn-in time before any auditioning. After the burn-in period, I ripped some more CDs.
HDX+nDAC
My first impression with HDX connected directly to the preamp was that it had a very decent and enjoyable sound comparable to good CD players of the same price range. I was curious how much the nDAC would improve the picture. Comparing HDX alone with HDX+nDAC, it was obvious that both devices were from the same house with almost the same tonal balance – nDAC slightly on the warmer side. But the improvement with nDAC was significant; there was just more of everything: more silence around the music, more detail, more tone colour, more air… And the highs came much more smoothly from nDAC; although the treble is more recessed in HDX, it has a harsh quality which can sometimes be very annoying.
HDX+nDAC vs. HDX+PS
I wanted to find our which one is a more meaningful upgrade for HDX. After a few trials, it was obvious: although PS did improve the sound of HDX, with nDAC the music was simply more vivid. nDAC (or another high quality dac) is a priority upgrade for HDX.
nDAC vs. my reference DAC
Believe me, I tried quite a number of very exotic dacs (some of them were very bad, btw). I can just confirm nDAC is one of the best dacs ever made and it can compete well beyond its price range, even more so if paired with the external PS. Is it the end of the road? Definitely not, there are a number of better DACs, but many of them at extremely higher prices! The DAC I had chosen some years ago through careful auditioning remains imo the best dac on earth. I wondered if nDAC could approach that sound. I made direct comparison feeding them from the S/PDIF output of HDX: my reference dac positioned all instruments so realistically in space; you can almost feel the air between each individual instrument even in the same group and all instruments have the right size and body. This almost palpable quality paired with a wonderful fluidity makes the presentation more realistic and musical. The nDAC remains somewhat edgy in comparison.
HDX vs. UnitiServe
For most of us the internal dac of HDX is futile, and we are attracted to UnitiServe as a less expensive alternative ripping device, assuming their digital outputs are identical. Well, I have bad news: their digital outputs are far from being identical; they are in fact two different worlds! Through my reference dac, the S/PDIF output of UnitiServe sound nervous, rough, and the micro-dynamics more flat (in comparison to HDX). The HDX has a more relaxed presentation, more resolved, better flow, and more precise rhythm. I tried to find out if the difference lies on the hard disk processing or on the S/PDIF output stage of the two devices. Having them both on the same network enables them to detect each other and play FROM each other’s hard disks. The sound of the files on UnitiServe hard disk was better through HDX output than directly from UnitiServe. Moreover, UnitiServe output sound better playing files on HDX than playing own files! I think this shows that BOTH hard disk processing and digital output stage are superior in HDX.
Well, we know for more than a decade now that bit is simply not bit – even “perfect bit” is not – and the digital music signal is an EXTREMELY FRAGILE signal. So, such differences should not surprise us. There are a lot of precision and timing issues associated with the digital music signal and jitter is only one of the problems. Can we blame Naim for this sonic difference? Look at the immense price difference. It is apparently not only for the internal dac.
I was not able to compare the UPnP output of the two devices with their S/PDIF outputs – I am waiting for the NDX! I also don’t know yet if the quality difference between their UPnP outputs will be as pronounced. I am pretty sure, though, there will be some difference.
THE MOST EXCITING PART (for me)
HDX vs. CD-transport
When I started this experimentation with Naim devices, I was REALLY hoping, for the sake of convenience, that the ripping solutions would sound better than my CD transport. This was of course an unfair competition for the HDX. This 66 lbs. heavy CD-transport is engineered to extract as much information as precisely from cd as possible. But I’ve heard so much word about the “sonic advantages” of ripping that I was tempted to make a direct comparison. No, HDX cannot come near. The CD-transport is in better control of all the micro-dynamics of the music giving a more realistic representation of all the different effort qualities and conveys the real intention of the musicians. It has better definition and gorgeously natural tone colours.
Does this mean ripping is inherently worse than cd spinning? Most probably not, but it means that the ultimate hard disk player has not been made, and that computers in general still need perfecting to be able to serve as ideal music sources, with more attention to isolation, vibration control, internal wiring, metal alloys in disks etc. HDX should only be compared with CD players in its own price range. There is no sonic miracle in ripping; it has convenience advantages for things like multi-room etc. I will go on SPINNING. (cd and vinyl!)
MY CONCLUSION
One can argue that all my comparisons have been on cd format, and that higher resolution formats available for download sound better. I am aware of the potential there. I am also very excited especially about direct studio recordings or the direct transfer of the master tapes on high resolution formats. But, my comment is still valid. If an environment (the computer) is not getting the best out of the cd format, it must be far from doing justice to higher resolution formats. I appreciate all the people who give a tremendous amount of effort, through careful component selection and so forth, to transform their home computer to a valuable music source. They are the pioneers of the field. I personally prefer to wait until Naim (or another respected music equipment manufacturer) makes a dedicated music computer which bypasses the general purpose computer already from download phase, and which is engineered to audiophile criteria.
I started by ripping some of my CDs to the on-board hard-drives of HDX and UnitiServe and gave all devices around 300 hours burn-in time before any auditioning. After the burn-in period, I ripped some more CDs.
HDX+nDAC
My first impression with HDX connected directly to the preamp was that it had a very decent and enjoyable sound comparable to good CD players of the same price range. I was curious how much the nDAC would improve the picture. Comparing HDX alone with HDX+nDAC, it was obvious that both devices were from the same house with almost the same tonal balance – nDAC slightly on the warmer side. But the improvement with nDAC was significant; there was just more of everything: more silence around the music, more detail, more tone colour, more air… And the highs came much more smoothly from nDAC; although the treble is more recessed in HDX, it has a harsh quality which can sometimes be very annoying.
HDX+nDAC vs. HDX+PS
I wanted to find our which one is a more meaningful upgrade for HDX. After a few trials, it was obvious: although PS did improve the sound of HDX, with nDAC the music was simply more vivid. nDAC (or another high quality dac) is a priority upgrade for HDX.
nDAC vs. my reference DAC
Believe me, I tried quite a number of very exotic dacs (some of them were very bad, btw). I can just confirm nDAC is one of the best dacs ever made and it can compete well beyond its price range, even more so if paired with the external PS. Is it the end of the road? Definitely not, there are a number of better DACs, but many of them at extremely higher prices! The DAC I had chosen some years ago through careful auditioning remains imo the best dac on earth. I wondered if nDAC could approach that sound. I made direct comparison feeding them from the S/PDIF output of HDX: my reference dac positioned all instruments so realistically in space; you can almost feel the air between each individual instrument even in the same group and all instruments have the right size and body. This almost palpable quality paired with a wonderful fluidity makes the presentation more realistic and musical. The nDAC remains somewhat edgy in comparison.
HDX vs. UnitiServe
For most of us the internal dac of HDX is futile, and we are attracted to UnitiServe as a less expensive alternative ripping device, assuming their digital outputs are identical. Well, I have bad news: their digital outputs are far from being identical; they are in fact two different worlds! Through my reference dac, the S/PDIF output of UnitiServe sound nervous, rough, and the micro-dynamics more flat (in comparison to HDX). The HDX has a more relaxed presentation, more resolved, better flow, and more precise rhythm. I tried to find out if the difference lies on the hard disk processing or on the S/PDIF output stage of the two devices. Having them both on the same network enables them to detect each other and play FROM each other’s hard disks. The sound of the files on UnitiServe hard disk was better through HDX output than directly from UnitiServe. Moreover, UnitiServe output sound better playing files on HDX than playing own files! I think this shows that BOTH hard disk processing and digital output stage are superior in HDX.
Well, we know for more than a decade now that bit is simply not bit – even “perfect bit” is not – and the digital music signal is an EXTREMELY FRAGILE signal. So, such differences should not surprise us. There are a lot of precision and timing issues associated with the digital music signal and jitter is only one of the problems. Can we blame Naim for this sonic difference? Look at the immense price difference. It is apparently not only for the internal dac.
I was not able to compare the UPnP output of the two devices with their S/PDIF outputs – I am waiting for the NDX! I also don’t know yet if the quality difference between their UPnP outputs will be as pronounced. I am pretty sure, though, there will be some difference.
THE MOST EXCITING PART (for me)
HDX vs. CD-transport
When I started this experimentation with Naim devices, I was REALLY hoping, for the sake of convenience, that the ripping solutions would sound better than my CD transport. This was of course an unfair competition for the HDX. This 66 lbs. heavy CD-transport is engineered to extract as much information as precisely from cd as possible. But I’ve heard so much word about the “sonic advantages” of ripping that I was tempted to make a direct comparison. No, HDX cannot come near. The CD-transport is in better control of all the micro-dynamics of the music giving a more realistic representation of all the different effort qualities and conveys the real intention of the musicians. It has better definition and gorgeously natural tone colours.
Does this mean ripping is inherently worse than cd spinning? Most probably not, but it means that the ultimate hard disk player has not been made, and that computers in general still need perfecting to be able to serve as ideal music sources, with more attention to isolation, vibration control, internal wiring, metal alloys in disks etc. HDX should only be compared with CD players in its own price range. There is no sonic miracle in ripping; it has convenience advantages for things like multi-room etc. I will go on SPINNING. (cd and vinyl!)
MY CONCLUSION
One can argue that all my comparisons have been on cd format, and that higher resolution formats available for download sound better. I am aware of the potential there. I am also very excited especially about direct studio recordings or the direct transfer of the master tapes on high resolution formats. But, my comment is still valid. If an environment (the computer) is not getting the best out of the cd format, it must be far from doing justice to higher resolution formats. I appreciate all the people who give a tremendous amount of effort, through careful component selection and so forth, to transform their home computer to a valuable music source. They are the pioneers of the field. I personally prefer to wait until Naim (or another respected music equipment manufacturer) makes a dedicated music computer which bypasses the general purpose computer already from download phase, and which is engineered to audiophile criteria.
I don't think there is any problem in you stating which CD transport you are using. After all Richard Dane (one of our moderators) instigated a long-running thread on various transports with the nDAC. 
Thanks for the input. I'm actually more curious to the rest of the system used for comparison and if any extras like line conditioners video bits etc. were anywhere to be found. I suspect not but an overview would help perspective.
Depending on associated bits, it's sometimes helpful to remove another dig or vid item from the mains before a listen to another as some already contain parallel conditioning or create noise at their power input that can affect other items hooked to the mains. It can sway an evaluation but I suspect you have already been down this path. Did you play with the ground switches? Has the DAC been used for a few weeks?I also hear differences in the various streamers and like a good transport but not as much as some of our HiDef sources. We use our old CDS-1s for spinning a dig out.
Depending on associated bits, it's sometimes helpful to remove another dig or vid item from the mains before a listen to another as some already contain parallel conditioning or create noise at their power input that can affect other items hooked to the mains. It can sway an evaluation but I suspect you have already been down this path.
Did you play with the ground switches? Has the DAC been used for a few weeks?I also hear differences in the various streamers and like a good transport but not as much as some of our HiDef sources. We use our old CDS-1s for spinning a dig out.js,
thank you for reminding about possible mains interactions. I use Audio Magic power conditioner; all compared devices were connected to the digital section and powered at all times (except when changing connections). Digital, low level, and amplifier sections are isolated from each other, but to my knowledge no isolation among the outlets of the same group. Therefore, I cannot exclude the possibility of mains interaction. I will check, although I don't really reckon it played a significant role in the outcome. My priority was to have all equipment equally warmed up at all times. I experienced this is very important in comparisons.
About your question on video bits on the rest of the system: I don't even have a TV in my home!
You're right! Many factors play a role in evaluations. I see that you are selling Naim and other British equipment in the States. I guess for you GBP/USD exchange rate plays an important role
thank you for reminding about possible mains interactions. I use Audio Magic power conditioner; all compared devices were connected to the digital section and powered at all times (except when changing connections). Digital, low level, and amplifier sections are isolated from each other, but to my knowledge no isolation among the outlets of the same group. Therefore, I cannot exclude the possibility of mains interaction. I will check, although I don't really reckon it played a significant role in the outcome. My priority was to have all equipment equally warmed up at all times. I experienced this is very important in comparisons.
About your question on video bits on the rest of the system: I don't even have a TV in my home!
You're right! Many factors play a role in evaluations. I see that you are selling Naim and other British equipment in the States. I guess for you GBP/USD exchange rate plays an important role
"I was not able to compare the UPnP output of the two devices with their S/PDIF outputs – I am waiting for the NDX! I also don’t know yet if the quality difference between their UPnP outputs will be as pronounced. I am pretty sure, though, there will be some difference."
Not sure what is meant here. UPnP is a streamed network file is it not? It certainly would be interesting to hear the differences between an nServe and HDX or for that matter a UPnP player such as Asset on a remote NAS or computer into an NDX. I would asume that streaming UPnP into a renderer should level the playing field a bit?
Now I'm beginning to see the reasons some are clammoring for a reference streamer that would have digital out to whatever dac was supplied. Getting away from having the HD directly attached to the Dac
makes sense in a number of ways not withstanding the convience factor of simply not having the boxes in the listening room.
Now all we need to do is to get Apple to have some sort of streaming protocol for higher resolution networked streaming. Unless that's already coming?
Not sure what is meant here. UPnP is a streamed network file is it not? It certainly would be interesting to hear the differences between an nServe and HDX or for that matter a UPnP player such as Asset on a remote NAS or computer into an NDX. I would asume that streaming UPnP into a renderer should level the playing field a bit?
Now I'm beginning to see the reasons some are clammoring for a reference streamer that would have digital out to whatever dac was supplied. Getting away from having the HD directly attached to the Dac
makes sense in a number of ways not withstanding the convience factor of simply not having the boxes in the listening room.
Now all we need to do is to get Apple to have some sort of streaming protocol for higher resolution networked streaming. Unless that's already coming?