Server power supplies

Start with a healthy bit of skepticism first.  Work back from the most sensitive device (NDS) and improve things as you move back toward your media server device(s).

But I'd offer the following caveat–why should one gut and replace the CE-rated switching power supply of an off-the-shelf server costing less than $1,000 (in the case of the HP MicroServer), merely to reduce its (perceived) influence upon a $10,000 streaming player?  And why are people seeking out aftermarket linear power supplies for products such as the UnitiServe, a product designed and assembled by a high-performance audio company well-known for its own (linear) power supplies?

More importantly–should the (optimized) performance of specialist-designed hi-fi equipment be left passively subject to the price-sensitive whims of commodity IT equipment suppliers, or should some reasonable degree of isolation and upstream-source agnosticism be designed into the products to insure a baseline of performance?

My thought?  Get a good-quality (need not be shielded, but may help) Ethernet cable to go between the (local) switch and your streaming source.  Keep all cable types the same between switch and streamer.  Evaluate the manufacturer-supplied power supply for your (local) switch to see if it negatively affects performance (using non-networked media, of course!) when plugged in–if so, replace with better supply.  Work back to front.

If, after all of this, you feel that there are additional benefits to be had by optimization of upstream devices, then your downstream setup will be transparent and revealing enough to reap the benefits.  On the other hand–if you feel that there is less return on time-and-investment spent upstream, then you'll be satisfied that you have achieved consistent, if not hair-shirt, system performance.

If you want to optimise your server setup, get yourself a unitiserve and use the Proliant for backup. 

There appears to me to be a good amount of common sense and reasoning in this reply.

It's like a breath of fresh air.

SJB

Lower noise floor. Improved listening ease and greater musical insight. The stock Naim (switching) PS works very well, until you hear the difference with a linear PS. It's not a subtle change.

 A linear power supply would be great if one could find out what make people recommend.

 Cue another hinted at name ? Please just post the name(s). 

The name will be modded if posted.  Just google "unitiserveps" and click on the first match.

Howard,

Per Hook's suggestion. Or consult my profile.

Thanks for the replies so far guys. I have no direct technical knowledge on this subject, so any views I may have are just developed from reading up on the forums and a bit of non-scientific experimentation at home. I don't want to spend money on this area for the sake of it, but if it offers marginal gains at reasonable cost, I think that is what this hobby is partly about.

Linear PS on Unitiserve: what do you think is the main driver for the enhanced SQ - is it that you no longer pollute the mains (assuming you have it on the same circuit or consumer unit as your main system), or does it help with the spdif output when feeding directly to a DAC. OR do you think it offers a benefit via Ethernet, even if the server is on a separate mains circuit?

Well, it certainly improves the sound over Ethernet. If a Supercap is better than a Hicap, why would a decent supply not be better than the three quid affair supplied with the UnitiServe?

My listening room (and the rest of the house) is festooned with SMPSs (phones, computer games, switches, routers. radios, NAS drives and chargers of all descriptions). I tend to think one more or less won't make a big difference unless it's plugged into the hi fi distribution block.

i guess I need to get a dedicated spur for the Hifi to sort it out. If I do, the Userve won't be on it. It will be in there with the routers, switch and NAS drives. Still the soft toy related PS is intriguing. I can see how it helps when the Userve is being used as a source (via SPDIF), but can it really improve a server? Those who have tried it say yes.

Keith 

Oh that name! I'm afraid clues had been too subtle.

Any others tried PSU specific to the Netgear switches? 

I specifically asked you not to reveal to the forum that I am working on a new line of power supplies to be named ChinchillaCap.  Sheesh.

... silly me, thinking Nigel was on about hirsute females.

Good thing your name is not Jimmy.

It is not clear to me whether this question has been answered:

Does naim recommend plugging the unitiserv and the nas in a different spur as the rest of the system?

I suspect if one has the unitiserv, nas and switch on the same spur, they're injecting noise into the mains - and a linear psu would help. you would at least two of these - one for the switch and one for the unitiserv - even if the nas is in a different room. 

If one does have the unitiserv on a different spur.,  I suspect the effects of using a linear psu will be minimal, my thoughts being that they matter mostly because they don't inject noise into the mains as a switching supply does.

According to me, the following might give the best results:

Nas + unitiserv + switch in a different room, on a different spur.

Streamer fed by a cinnamon. Cinnamon hooked to a switch fed by a linear psu. Switch hooked up to the switch in the other room with a standard cable.

Alternatively, use airport express near the streamer (fed by a linear psu) - and wirelessly stream to it from  an airport extreme in the other room.

Thoughts?

Core audio in the USA has something called a pixie - linear psu to use with switches and to replace smaller wall warts.

Oh yes! My Mac speed has increased dramatically since it put a linear power supply. It also makes less errors reading and writing bits on the hard disk. The colors on the screen are deeper too .

Michel

Precisely.

I remember the days when I used to play on PC. I had relatively good PS and everything worked flawlessly, but upgraded to Corsair dual ray 750W PS and left speechless after I find it bring additional 7-8 FPSs to 3D games. You can make fun of me if you wish, but this is what happened.

I love the fact that there is so much 'belief' in tinkering with streamers, routers, switches, Naim servers, Naim power supplies, third party power supplies, DR vs non-DR, and turn tables.  Yet, when some one mentions about upgrading the power supply of a computer, if gets treated as a joke .

That's not the same constraint–many ATX power supplies provide very poor regulation on the 12VDC rails as the load approaches capacity.  I've seen the exact same effect with multiple 4-port ethernet cards in an industrial server chassis.

Question is–has anyone compared the HDX-SSD to a UnitiServe-SSD running a linear power supply?  The HDX uses an internal SMPS that provides a single DC rail for the computer side of things, as opposed to the outboard line-wart SMPS (also single-rail) used on the UnitiServe–is the allusion being made here that the HDX power supply is not up to snuff, simply because it is a switching supply?  (Seriously?)

I thing we have to consider 2 different usage of the UnitiServe:

As a player to the SPDIF port, it should be connected to the same spur as the rest of the system and there, a linear PSU may improve things.

As a server to the Ethernet port, it should not be connected to the same spur as the HiFi, but to the same as the network infrastructure devices (router, switch, NAS..). Here I still have to have a convincing demo of the effect of a linear power supply. My experience is better PSUs bring better reliability\QoS to the network, not much better sound quality.

I use mine over Ethernet, but due to room logistics, it's far easier to plug it into the same spur as the SuperUniti. This is why I got a linear power supply. But I must say, the improvement to sound quality was very significant, even with my relatively basic system.

My Unitiserve-SSD is feeding SPDIF into DAC/XPS, with the NAS/Switch/Router in a separate room. Plan to move to an NDS sometime but its quite a jump.... 

• On dealers advice US PSU is on the systems mains feed (keep common ground-plane), but carefully positioned so PSU & cable runs are far away from all other eqpt (as was best practice with NAPSC).
• Netgear switch and DSL router are on a low-noise Dual12 linear PSU along with CAT6. Both made a dramatic contribution to lowering the noise floor and assisting a purer musical flow, especially noticeable when the rest of house power is quietened..
• Experiments turning off ALL smps around the house (DECT phones, all chargers, printer) make a real difference - with HD files  the closest to best analog I can remember.  If it was like this all the time I'd be very happy.  So I've come to conclusion the US PSU by itself isn't necessarily the major offender.  I'm working on the other root-causes, have a linear/filtered 9v/5v PSU winging in to trial as wall-wart eliminator.

I appreciate others have experienced gains from the common after-market US PSU, on both SPDIF and Ethernet configs.  Mixed feedback is it does some things VERY well, BUT also has its own sonic characteristic which doesn't 100% convince everyone.  BTW it is NOT linear - it uses a medical-grade SMPS to deliver current capability followed by linear regulator.  So should offer low earth leakage current and EMI - but couldn't get any clarity re noise level introduced back into mains where US PSU has the in-cord filter.

So I'm waiting to see what Salisbury produce - they have a benchmark to better - and in meantime cleaning up rest of my electrical environment which helps all the components perform to their best.  Noise in an overall system can come through several vectors, and have multiple mitigations.  I'm choosing to focus on the 'externalities' first  However, I'm also tempted to buy one of the American Mac-oriented 12V linear PSUs as a trial, with the plan to move it onto the NAS over time.