Where, in Naim’s servicing cost would the N50 be?
A service is to help prevent future failure. Caps represent a large part of that failure risk, but also, other items are inspected and changed if required.
Your initial post was regarding MF products that are 25 years old. What are their service history? If none, then most would suggest a service. Caps degrade with time, it’s a chemical thing, accelerated with increased temperatures. And yes MF were well known for buying the cheapest components. However, many of their caps I have tested for ESR and capacitance have tested well, but the item always sounded better once they were replaced. Saying all that, MF did have a good reputation for reliability. As one well-known repairer says, if he was making a living from MF repairs he’d not have much of a business.
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Interesting, when my 200 came in for repair some years ago it was fully serviced without discussion.
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With mechanical things yes, but not really with electronic, at least not regular servicing at less than 25+ years. Of course there can be individual exceptions where, fir example, a capacitor fails explosively 10 years, to the best of my awarenessthe chances of that happening are not much different from the chances of it happening after 10 months or 10 days, so the routine servicing after 10 years is unlikely to be of any significance in the prospect .
Routine servicing of amps etc is primarily to keep then up to spec so they perform close to how they did when they were new, and how much they actually change in 10 years for two years or whatever is likely to depend on the amp design and the choice of components.
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Yes, absolute failure and degredation. But measuring that degredation often means removal, so an exchange may as well be undertaken.
What gets described often as a service is more correctly an overhaul. Similar for watch services. Strickly these are more often overhaul.
Actually no. An ESR reading is taken of caps in circuit.
If you had a mystery cap and wanted to know what it’s capacitance was so you could find a replacement, then you would need to remove it for an accurate capacitance reading.
So providing you know the cap’s spec, you leave it in place for the ESR measurement.
Not sure that is correct… it depends on the application. As I said earlier if you have cascaded reservoir electrolytics smoothing valve HT lines of say greater than 1kV it is recommended to replace those capacitors every 10 to 15 years.. as age related ESR could lead to the electrolytic exploding (due to heating )… straight forward to do… but ensure caps are discharged first before you work on it.
Sure low voltage applications are less critical.
The need for removal was to check capacitance. Certainly for MF it was never a guess as it was marked on the cap. However, their caps often measured as expected. But in my experience the item sounded better once replaced.
Capacitance often (in fact usually in my experience) measures within spec long after a cap has perished, hence preference for ESR as a better guage of degredation.
The last few power supplies I recapped both failed to power up more than a split second, yet their caps read bang on spec. Replacing them resolved the issue. Their ESR was way off though.
As such I tend to use an LCR for grading and selection but an ESR for troubleshooting.
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Reading the responses here make me worry. I think it’s time I install the Naim amps and listen for few days (or weeks) before I leave them unpowered for months. The amps have not been used for more than 2 years.
Another integrated amp which I have (Sonneteer Orton) has not been used for 5 years if not more, and I guess it’s also about time..
Slightly off topic but I think amusing to some readers here are the scenes in science fiction movies and television where someone in the future finds a contemporary computer or device that is, to them, hundreds of years old. They turn it on and it works!
As if 
In the minds of fiction writers, anything solid state works forever. The caps never degrade. Tubes never leak in air, connections never rust to dust, screens never fade.
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Ah yes, in that post I was forgetting valve amps with their higher tress on high voltage capacitors in valve gear, though I had mentioned their higher risk earlier.
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They do degrade.
My interesting experience: I bought my 32.5 from an old dude who goes so far to take great cares of his gears. All the daughter boards were rarely used, wrapped well and vacuum treated, placed into a cabinet with 24/7 temperature control, so as the 32.5. But later it’s confirmed the Roe caps are out – not as bad as those on auction sites but performance isn’t there, sound takes long time to settle and occasional peaky response.
That’s probably because some repairs, for example where a regular service item such as a capacitor has failed, just require a service to fix. However, if say you had somehow blown the output devices on your NAP200 then that would likely necessitate a repair as well as a service.
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Not sure what “treated” means here? If vacuum packed, that is not necessarily a good idea if the board has electrolytic capacitors as it could cause their seals to fail resulting in leakage. Best storage is in dry cool air: hermetically seal in a bag with a desiccant like silica gel and store somewheres cool. (Which prompts the seaoarate observation that unsealed storage of electronics in a loft may be the worst place!)
Vacuum tubes from the 1920’s for audio use are still easily available in the 1920 they could probably have been regarded as mature but evolving technology as vacuum tubes had been in use for something like ten to fifteen years already by the 1920’s I believe.
It continues to amaze me that something that’s essentially pretty fragile can be 100 years old and still work let alone actually sound amazing.
It’s always a nice moment to roll in a vintage tube and be able enjoy the experience of listening to something from those times.
it was evolving but definitely not mature - I think by the time we got to the mid 60s as they were being phased out development mostly stopped I suspect they had reached peak technological maturity, certainly in the West.
The first thermionic valve was invented in 1906 - it was a basic prototype triode in the lab. Move forward to the 1916 the first practical valve was designed to be used in an amplifier. The technology matured over the following decades and I suggest the 1930s and 1940s saw the fastest technology development and maturement as many use cases and variants appeared from digital switching to cathode ray tubes, magnetrons, planar valves, high speed switching and lower power and smaller devices as well as valves being able to support very high frequencies and huge power, spurred on by the looming and subsequent Second World War and the early telephone digital switching systems in the US.
The Cold War helped develop newer valve technology with low power and miniaturization to control nuclear ballistic missile guidance systems and be resistant to EMP, but at this point semiconductors were increasingly used where they could - albeit early semiconductors were relatively unreliable and fragile - just like some of the early valves were from the ‘20s.
Some of these Cold War ballistic missile valve types are quite popular in some valve headphone amps these days!!!
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Thanks I have a few Bendix 6080WB tubes that I roll from time to time in my otl amp. I have read more than a few times on forums over the years they were used in both early jets and missiles in the power system and whilst I’ve tried to search for info to see if I could confirm this have only really confirmed they were used by the military for power regulation.
They do however sound rather superb and are of serious construction, widely regarded as amongst the best sonically of that variety available.
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well the military valves tend to be ruggedised so designed to last longer and take more abuse 
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With valves being replaced with transistors you’d have thought by now that a suitable replacement for a life-limited capacitor would have come along. I’d have thought 2 conducting plates and a dielectric inbetween would be possible that doesn’t rely on chemical components that degrade over time.