Fork in the Road: 500 Service

My 500 amp, bought used 10 years ago, is acting up and I am considering my options. Specifically, the Power button is stuck On, and powering up by plugging in trips the dedicated 20-amp (US) panel-breaker twice, before amplifier becomes usable on the third try. I imagine there is some power-up sequence managed by the PS500 that is no longer working. Though, before the Power button seized, it was the same story — powering up tripped the breaker, usually twice, before success. At 15 years old, it is time for a service anyway.

Now that service-upgrades to DR are no longer offered, I must choose between servicing at the current non-DR level, or trading to a new or refurbished 500DR or 300DR — alternatives I have not yet priced.

I have been and remain completely satisfied with the 500 in my system; I am sure that it is making the most of my very-modest but reliably-pleasing KEF Q-50 speakers. Certainly, I plan to upgrade the speakers one day, though in trials to date the KEFs have stubbornly won the right to stay.

Grateful for opinions from the community. And, what about the breaker-trips? Amp fault, wiring deficiency, or working as designed?


In relation to the tripping, in the UK, the standard consumer fuse breaker is called a type B. However for Naim gear, it is advised to get a Type C breaker which has a slower fuse time, and this allows the Naim gear to get that rush of current it needs at startup. Is there an equivalent in the US?

Can’t advise on anything else, but I suppose it also depends on what a service costs, and what the trade offers our. If your 500 is faulty, it may make sense to get it serviced before selling.

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Thank you, @GadgetMan.

Good to know that using a “slow breaker” is not unheard of in some jurisdictions.

Plugging that into my decision.

AV Options is frequently ready with fast-turnaround alternatives/exchanges vs. waiting for repair of the submitted unit.

The trick is knowing what you want!


I had the same problem with my (nearly) 20 year old 500. The tech at Gig Harbor Audio replaced the power button on my 500 power supply. Give them a call… It was not terribly expensive.

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Thank you, @Chris.

Gig Harbor Audio are on my radar.

At this point, I think a full service is probably opening ante. I will see what they say.



AV Options would be your best bet for recap service. Chris West does the finest work.


Thanks, @Chris.

I seem to recall you made the 500 to 500-DR upgrade without regrets.

Is the trade-up a no brainer, if cost is not a factor? Or are there trade-offs, in your experience? I know a select few prefer the 300 and/or 300DR at any price, making choices harder without self-sponsored demos.



For many Naim products there is a list of informal rudimentary Naim sanctioned repairs that dealers can actually do. The stance that only Naim or authorized service centres can do any work has some surprising exceptions so you never know unless you ask the dealer.

Back to the original problem, in generic terms, any item that is in need of repair or service will affect the resale value by more than the cost of the service. So it really depends on fast you want to turn something around into cash.

If the case work is in good condition, plenty of buyers actually look for those bargain discounted bits because they also want to get the Naim service to happen on their ownership clock if you get what I mean.

Getting it fixed and enjoying it non DR is certainly a valid option too. When I DRed my 250, it effectively became a different amp. One which I had not demoed with my speakers… and the result was that the DR version didn’t integrate as well as the non DR version and I ended up changing speakers too. DR will be better. But it will be a different amp too. It might sound a lot better. Or it might not. No one else’s opinion or experience is really going to provide any guarantees here.



  1. Took advice to suspect the 20 amp panel-circuit-breaker — had it replaced and PS500 no longer trips it. My dealer advised there is no power-up staging in the PS500 — if there is no fault in the circuit, the breaker may be (is/was) out spec.
  2. Even though my PS500/NAP500 is c. 2007, fixing the stuck power button is a job my local dealer can do. Since sound is still spectacular to my ears, maybe I can get by for a few more years before service, after all.



For me I would get it serviced and DR’d. Using the man math principal, the outlay amortised over say 15 years will be minimal per year, plus with inflation you might even be able to sell it for what you have invested in it at the end, if you decided to go that route.

The pleasure my 500 kit gives me is worth every penny and compared to other hobbies is not that bad at all for what it brings.

As mentioned above, the stuck push button is a rather common issue. I experienced this myself and it was not costly to fix. The distributor actually suggested that I dont necessarily need to repair the switch if I just continue switching it off by unplugging. I was impressed by this straight forward problem solving.

The 500 is a fine beast by itself and the other exchange options are way more involved and/or expensive. Maybe the power supply could benefit from a re-cap once it is in repair?

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Naim no longer offer DR upgrades, hence the dilemma for the OP.


Ah thank you. I thought that was temporary though with supply chain issues, not permanent. thanks for confirming

Like a lot of things its back to cost and how much you can or want to spend. Either way a pre DR or serviced AND DRd is a desirable product.
One option is to get the amp fixed and either live with it or p/e for a (used if you are lucky) new 500 DR. The DR makes it into a really better and different animal from the off for me.
Its often worth biting the bullet now. The way things are prices for everything seem to be on the up.


I sometime start to that that people believe that anything ‘pre-DR’ is now in someway rubbish… :astonished:

If I were the OP, I would get my 500 serviced and its switch fixed - then enjoy it for a while. If the DR bug has got its teeth in, then perhaps then start looking for a 500DR, pre-loved or ex-dem. If one appears… so be it. If not… keep playing the music… :grinning:


I just had my two 135s and two Hicaps serviced and re-capped after the last service almost 15 years ago. I also replaced the SNAICS and DIN leads. I am sure I am not the first to say that this is such a good thing to do. I am sure they will replace the power switch on your 500 if there is a problem with it. Then enjoy the new lease of life in your familiar gear and if money starts to burn a hole in your pocket then you will at least be able to sell/exchange your serviced equipment much easier than ones with a problem. Good luck whatever you decide to do.


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