Variation in sound quality

Posted by: roosevelt51 on 27 October 2016

Hello all - I'd be grateful for any thoughts on the following.

About 18 months ago I converted to streaming and ripped 3000 plus CDs, plus downloaded a number of hi res files. I had to give up work three years ago because of ill health.  It was a bit of a blow having to give up work, but the positive side of it was that I now get to listen to a minimum of six hours music a day. I also have to go into hospital every 12 weeks for treatment which really knocks me out, but again the positive spin is the opportunity to listen to music when I'm recovering at home. Sources for listening include rips, downloads, internet radio, satellite via a Sky box. My equipment is as follows:

NDS + 555PS
NAC552 plus Power Supply (of course)
NAP500 plus Power Supply (of course) non-DR
Unitiserve – which is only used to rip CDs and then sends them to a ReadyNAS
Ovator S-400 speakers
Three Power Line mains cables

All the above were bought new within the last 18 months or so, with the exception of the NAP 500 which is more than 10 years old, but was serviced by Naim last year. The system is never switched off (apart from thunderstorms, etc).

My musical tastes are pretty wide ranging – rock, pop, classical, jazz, acoustic.  I've owned Naim-only equipment for more than 17 years now, including 135s, NAC52, DBLs, CDS3, so I'm pretty familiar with the Naim sound.

My issue is that the sound from my current system varies. At times it seems “on the money”, with real presence and definition and engagement and at other times is appears recessed, unfocussed and uninvolving. I was going to use the word “muffled”. That doesn't quite describe it, but there’s a definite lack of definition and a blurring – “veiled” and “flat” are words that spring to mind.

There appears to be no rhyme, reason or pattern to when this kicks in. It can happen after 30 minutes, or three hours. It can happening after I’ve used the mute button or not happen after I’ve used the mute button. It can be present straight away when I start playing something, or not be present straight away. It can happen at any time of the day or night. It’s the same from all sources – NDS, TV, Blu Ray. I live in a rural community – there is no heavy industry, but there are a couple of farms.

I have a battery back-up attached to the NAS in case of sudden power loss. This incorporates a voltage readout, so I know pretty much what voltage is powering the equipment at any time. The effect I’m describing doesn’t appear to be affected by any fluctuation in voltage, high or low.

Cable dressing, separate sockets, speaker positioning etc., have all been addressed and there was a definite change in sound – but the problem still keeps manifesting itself.

I’ve tried to be as specific as possible, and would be grateful for any advice and observations forum members could offer. Sorry for such a long post, and many thanks in advance for your help.

Posted on: 27 October 2016 by nigelb

Can I ask if you have noticed SQ fluctuations on the same albums/tracks? Just to be clear can an album sound great one day and the same album sound not so great the next day? Or do some albums simply sound better than others?

Posted on: 27 October 2016 by james n

Sorry about your ill health - discounting just not being in the mood for listening, do you have anything else (such as the sky box) on the rack with the Hi-Fi ?

James

Posted on: 27 October 2016 by roosevelt51

Hi,

Yes, the sound fluctuates on every album - sometimes the sound will change during the playing of an album.

 

Posted on: 27 October 2016 by hungryhalibut

It sounds as though something else on the mains, or some sort of RFI interference is involved here. Do you have dedicated mains with a separate consumer unit? Are you using proper wired Ethernet, not wifi or Ethernet over mains? 

Posted on: 27 October 2016 by roosevelt51

The Naim equipment is on a Quadraspire rack and plugged into a Musicworks block. Sky box, Blu Ray, are not on the same rack and a few feet away.

I should have mentioned in my original post that my dealer substituted the Naim boxes one by one.  I had each piece of kit for a few days and each time the sound issue occurred several times.  Naim even came out and did some fine tuning (cable dressing, speaker positioning, etc.). It did make a difference, but the next day the sound issue came back again.  The trouble is - of course - that the effect I'm talking about doesn't happen when my dealer is here.  

One theory that's been put forward is that it's environmental.

 

 

Posted on: 27 October 2016 by james n
roosevelt51 posted:

The Naim equipment is on a Quadraspire rack and plugged into a Musicworks block. Sky box, Blu Ray, are not on the same rack and a few feet away.

I should have mentioned in my original post that my dealer substituted the Naim boxes one by one.  I had each piece of kit for a few days and each time the sound issue occurred several times.  Naim even came out and did some fine tuning (cable dressing, speaker positioning, etc.). It did make a difference, but the next day the sound issue came back again.  The trouble is - of course - that the effect I'm talking about doesn't happen when my dealer is here.  

One theory that's been put forward is that it's environmental.

 

 

Ok - that rules out one thing. Sounds like your Dealer and Naim have been very helpful and something external is at play.  Apart from your voltage monitoring on the UPS, Have you had your mains checked out particularly with respect to earth impedance. Have any of the farms got any industrial equipment or large solar installations ?

Posted on: 27 October 2016 by hungryhalibut

Which is why I asked the questions I asked.... and the answer is?.....

Posted on: 27 October 2016 by roosevelt51

No, we don't have dedicated mains or spur. We live in a rented property so that's not possible, unfortunately.  It is Internet over mains, but the NDS is connected to the ReadyNAS directly (via a switch).  I thought there might be going on with the Internet over mains and something else polluting the mains, so disconnected the Internet from the NDS, unplugged other electrical equipment - sorry to say still had the issue with the sound quality.

Posted on: 27 October 2016 by roosevelt51

They're small farms (it's a small village), no heavy industrial plant or solar installations.

Posted on: 27 October 2016 by Mike-B

You have a lot of worthwhile tips to follow up on.  If you haven't done it already I would also completely pull the EoP plugs as just being on the mains can cause issues.     Also if I can add one more:  your property should have two or more power circuits,  can you rig a temporary extension lead from another circuit to see if it changes the problem.

Posted on: 27 October 2016 by Pcd

I would ask if you could have your mains supply monitored sounds like it could be an external problemy. 

Posted on: 27 October 2016 by Harry

I would suspect mains. Mine appears to vary considerably and as far as can be told, sounds better when the street is mostly out or asleep. A tricky thing to test though. It's not so much about voltage variations (mine swings plenty) as quality.

Posted on: 27 October 2016 by dayjay

Sound quality does seem to vary at different times of the day or night and I have also always suspected it was mains related and down to local demand on the system.  I get it less when listening to digital, perhaps because my dac is battery powered, but there is still variation.  Used to get it a lot and at a more noticeable level when I was using a streamer straight into my amp.

Posted on: 27 October 2016 by Bert Schurink

Like others I would suggest you concentrate on your mains. It's not uncommon to have variations because of that reason.

Posted on: 27 October 2016 by Simon-in-Suffolk

Poweline Ethernet adapters I would eliminate and see if things improve. They are quite shocking for creating polluted mains and RFI. Quite honestly until they are removed a quality system such as yours will struggle.. it may not be the sole issue .. but almost certainly holding back your system performance.

Ethernet needs its own wired connection, it can't  be carried over the mains without conversion to its own proprietary non Ethernet link protocol, and the way the mains is modulated to carry this new data format produces a relatively large amount of RF energy that will flow to connected devices on the mains and create quite a relatively strong RF field sstrength within your house. Neither of these things is good for sensitive audio componentry. Remove that source of noise and then focus into other things that might be upsetting the system

Simon