UnitiServe HDD & Reclocker

It might help if you said what your DAC was. The US is a pretty decent digital source so i'd not get too hung up on the reclocker - more useful when you've got a more 'downmarket' source such as a Sonos connect rather than one designed to deliver a high quality S/PDIF output (like the US)

Oh and welcome 

James,

I use an NAD Master Series M2 integrated amp.  This Class D amp contains its own DAC.  The amp takes either a digital signal or it takes an analog signal and converts it immediately to a digital signal.  It sounds best when fed a digital signal.   I know some, Esoteric comes to mind, that promote external clocks used in concert with their CD transports.  I use the UnitiServe to play files of the CDs that I have ripped to its hard drive.  I don't use its streaming capabilities.  I realize there are poorer sources as far as timing errors go than my UnitiServe but I'm wondering if jitter is still an issue with its output.  Would a better clock be worth the relatively small cost of $400 inserted between the UnitiServe and the MS M2? 

Not so many here seem to use the UnitiServe directly connected to a DAC via SPDIF. I do not know why this is the case. But I guess you will have to run a test yourself to decide whether it is worth reclocking the UnitiServe output in your particular setup. If you do so, please, report your findings!

What I can say for sure is that the quality of a USB to SPDIF converter (connected to a dedicated, headless computer running a music server on a minimal Linux distribution) does have an impact on the sound quality of a Naim DAC.

But I do not know the MS M2 and I would hope that the SPDIF output of the UnitiServe cannot be significantly improved by an external clock. But who knows ... maybe it can!

Best, nbpf

Hi Griffheel, and welcome to the forum.

I use my UnitiServe directly into the Naim DAC or the Resonessence Mirus DAC. The UnitiServe responds very well to a properly designed linear power supply. I've never felt that jitter was an issue and would be very hesitant to add a reclocking device, especially one that runs off a switching power supply, due to its potential for introducing noise into the digital signal. 

Jan

Jan, thanks so much for your advice.  It sounds like I may cause more problems than I solve.  I'll stick with the present setup, sans external clock.

Tom

The US can deliver a VERY high quality SPDIF output, but this significantly hindered by its standard power supply.  Keeping data in WAV including hi-res makes a significant audible improvement, as the CPU then only has the minimal effort of feeding data blocks from disk to PCI SPDIF interfaces - FLAC is noticeably inferior.

Some popular third-party replacement supplies are also a very mixed bag, being an un optimised SMPS followed by a regulator, still generating significant noise on both the SPDIF and upstream mains supply which hobbles overall system performance. 'True linear' low noise supplies tend to be fairly expensive, but IMO are critical to top performance.

 In a recent home trial my 'pimped' US was in a completely different league than an ND5XS for SPDIF into a DAC/XPSDR.

I've mused on the potential of SPDIF isolators/re generators, but these seem to mostly target the USB-SPDIF market and nothing has stood out to me as a clear option.  Better IMO to fix the root-cause problems....

In mentioning 3rd party power supplies would you be suggesting our Israeli friends being amongst those delivering a mixed bag?  Maybe I made another mistake?

Yes, the Israeli one is the SMPS followed by a regulator, but does not provide sufficient current to boot up the UnitiServe, or to rip discs (in my case). Best avoided. Discussion of that company's products is off limits on this forum, but PM if you need details (email in profile).

Jan

Jan,

Can you suggest a "properly designed linear power supply" by name or is that a violation of the forum rules?

Tom

Yes it is a violation of forum rules. Drop me an email.

Also well worth trying Audioquest Jitterbugs in one or two of the USB inputs on the U/S. Only £39 each in the UK.  I'm currently running a £250 Pioneer streamer as an interim measure while I make my mind up between 272 and an NDX. The Jitterbug has made a very big improvement to it and I could live happily with it during extended deliberations (or procrastination!).

Olly

Hi Tom

I took a look at the Remedy and noticed that it seems to re-clock/re-sample to a fixed 96k rate.  While this may be ok for generic sources (like iPods, TVs etc) I wouldn't recommend it with your US And 44.1k CD rips - it would be a retrograde step.

Martin Colloms in HiFi Critic rated the "augmented US HDD" (augmented by a high quality linear supply) at 250 points which is very high on his scale and not far behind an NDS' output.  So this is the one 'big hit' to transform its performance.

In the interim I would recommend ferrites on your SPDIF cable,  on the Ethernet connection into the US, and on the US power cable itself as possibly reducing noise effects into your amp.  All of these brought more openness, ease and detail for me.

 Also, ensure you use the supplied Naim power cord with the filter.  It would be worth experimenting on power outlets it is plugged into - the same as your amp for common grounding, or a separate outlet/spur to reduce transmitted power line noise.  You need to ascertain the best in your actual configuration.

Try some physical separation from your DAC/amp, if not already we'll clear - and keeping the SPDIF and power cables clear of all other cables.  It can all add up to make a significant difference.

best regards

40 below,

Thanks so much for the advice.  Jan-Erik has suggested a source for a good linear power supply.  I'll work towards saving my pennies to acquire one from his suggested source.  

Tom

40 below,

One question:  Where would I find ferrites for my cables?  I have to admit my ignorance.  I don't know what these are.

Tom

Hi Tom

sorry .. we don't all come from similar technical backgrounds!

You will have seen ferrites, though not recognised them.  The small cylindrical/drum like bumps on most laptop power cables or computer monitor cables are ferrites.  They are a metallic compound that has a strong effect on electrical conduction at certain frequency ranges.  They can be used in transformers to couple energy, or in 'chokes' to impede it's flow. It's the latter use we want - to impede high- frequency noise currents while letting the main signal flow.  Cables pick up or conduct extraneous noise from SMPS power supplies, wifi/radio signals in the air, etc as well as the main signal they're intended to carry. Ferrites help reduce this unwanted noise pollution.

While digital signals of a volt or so can tolerate/ignore background noise, when this noise couples into delicate audio gear it can increase jitter, introduce unpleasant harmonic distortions, or mask the fine detail down in the millivolt/microvolt levels which gives good music it's magic.

look at www.fair-rite.com (a world-leading manufacturer) under products -> standard products -> suppression components -> cables -> round cable Snap-It's for their product selection.  You can probably buy these from Radio Shack or an online outlet for a few dollars each. They come in different diameters for different cables, 6.3mm seems to fit many mains and Ethernet cables, and something closer to 10mm for SPDIF coax cables. The '31' compound is fairly general purpose for high- frequency noise, but for lower-frequency SMPS power wires the HY2 iron powder compound is particularly effective.

Clip  split cylinders around each end of cables - you'll hear if the music seems to clear and open up.  I avoid my main audio system power and signal cables, but target the various digital devices/power supplies and connections around them.  

Toroidal (donut) rings can also have a few turns of cable wrapped around them for a stronger effect but be careful to not over-bend an Ethernet cable, I think the minimum recommended radius is something like 10x or 20x the cable diameter.

there's virtually no cost and nothing to lose in a little experimentation..... You could spend $100s in cables to achieve the same basic effects.