Naim sound quality before and after a service

[peterm]

I’m curious as to what this ‘design flaw’ might be? Does it apply to all the regulated amps, 250/300/500?

What Mark describes as a design fault is perhaps a case of Naim never paying more than they needed to for components and consequently rather under specifying some components (i.e. a NAP180 I bought a year or so ago had a power supply voltage of 39.3 volts and the the reservoir capacitors were 40 volt rated, a bit close for comfort, especially if you have a high mains voltage).

The specific "flaw" on the 250/135 regulator boards is the marginal rating of the power supply regulator boards' 10 microfarad capacitors which could be uprated to higher voltage/higher temperature versions to advantage.
These capacitors are the ones that regularly fail on 10 years or so old 250/135s and is where the legend of Naim amps needing regular servicing comes from.

If you can do it yourself they're cheap as chips and the rest of the range probably don't need servicing for MUCH longer periods.

 

[davidsrsb]

Why does Naim equipment need servicing so regularly to make it sound good?

Leaving switched on permanently is Naim culture and is 10,000 hours per year. Ten years of that will kill most electrolytics

 

[Woodface]

I don't think it is just naim culture

 

[MJS]

The 180 and Supercap transformers rectify to just shy of 40v DC and in many cases slightly over. The SC transformer was used in the XPS v1 and they regularly cook their capacitors completely.

 

[Rockmeister]

18 or so for a normal amp, yes. But the 250 has an inherent design flaw and those caps need replacing sooner. Trust me, it'll sound much better after the service even if you think it's fine now.

claim against the maker then...selling a product that is known to be defective at sale...isn't that an offence, or anyway against the trades descriptions or whatnot? Caps don't (shouldn't) wear out in 10 years. 30 or more, maybe?

 

[Woodface]

I can guess the direction this thread is going...

 

[Minio]

claim against the maker then...selling a product that is known to be defective at sale...isn't that an offence, or anyway against the trades descriptions or whatnot? Caps don't (shouldn't) wear out in 10 years. 30 or more, maybe?

Like they used to sell cars with mechanical ignition, knowing full well you would have to change the points in 6 months!

 

[Mike Reed]

I'd say that if you have a 250 which sounds a bit like a valved amp then treasure it ! I went from 250 to 2 x 135s to E.A.R. valved mono's which are considered the s/s equivalent of valved amps. Quite a difference. To be fair, the 10 year 'rule' is set on the safe side, understandably, and my amps well exceeded that timescale, despite or possibly because of 24/7 power-up.

Don't think the jury ever came out on whether powering up/down every time caused more problems for the cap's that ticking over at the same temperature on 24/7, but that controversy was hotly debated at least a decade ago. One would have thought that the longevity of those cap's under different conditions would have been verified many moons ago.

 

[Dee-Kay]

My 180 was around 14 years old when I decided to have it serviced and was told I caught it just in time. Some of the larger caps were visibly burned. I was quite surprised at how much had been changed out including transformer bolts given back in a plastic bag when I collected it.

I can’t honestly remember if I thought the sound had deteriorated, I was so used it I expect it had but I wasn’t sure so thought it best practice from what I’d heard. I recall it took at least a month of the sound, particularly the bass being all over the place, which I was warned to expect. Once it settled in the benefit was clear, there was no down side.

 

[tiggers]

Trust me, it'll sound much better after the service even if you think it's fine now.

I have 4 135s and last year had them serviced at 12 years since their last service. I didn't think there was much wrong with them, but as one was beginning to develop a loud pop through the speakers at power on I decided it would be prudent to get them serviced. Having got them back and run in for a few weeks or so I can honestly say they are better in every way than before the service. My partner even commented how much more open yet in control the systems sounds particularly on high treble and she's not one for commenting often. I know there's always an element of wanting to hear a difference having shelled out £1K, but this is not that, they definitely sound much better and I know they are good for another 10 years.

 

[Woodface]

I have 4 135s and last year had them serviced at 12 years since their last service. I didn't think there was much wrong with them, but as one was beginning to develop a loud pop through the speakers at power on I decided it would be prudent to get them serviced. Having got them back and run in for a few weeks or so I can honestly say they are better in every way than before the service. My partner even commented how much more open yet in control the systems sounds particularly on high treble and she's not one for commenting often. I know there's always an element of wanting to hear a difference having shelled out £1K, but this is not that, they definitely sound much better and I know they are good for another 10 years.

A grand is not a lot of money to keep 4 amps on the road

 

[Rack Kit]

A few months ago I sold my unserviced 2005 build 300 (bought used in 2010 - installed 2012) that sounded fine. The buyer was coming from a virtually new 250DR and was bowled over by the upgrade in sound quality.

I keep my gear on 24/7 (bar electric storms & the odd strip down etc) and think that amp is good for another 7-10 years use before needing a service. TBH, I didn't notice a huge difference between it and the DR, so know that the standard 300 was very healthy condition.

Couldn't find a buyer on here for it though!

 

[SteveH]

I had an olive 250 that I got serviced after 10 years because that was the received wisdom.
It sounded a bit better afterwards but I wouldn’t have bothered had I known how little sonic difference it would make. Never left mine on all the time tho’.