It all went Pete Tong!

So I came back from the pub last night, fancied a dance so got Peter Tong in da mix on Radio 1 - playing at 12,00 o’clock on my new 282/ 250 dr ( as I’ve done so on plenty of occasions since I bought the amps in July) then suddenly the fuse blew…

I know there’s a spare but I’ve previously owned 200/202’s and the olive 90/92’s and in 25 years of running them high have never experienced a blown fuse, I expected much more from my latest purchase…

As I said I wasn’t running the amp that high, so can someone please confirm what went wrong, is this common with 250 dr’s, or is it just a faulty amp ?



I would say that running the amp at 12:00 o’clock is quite high but even so it shouldn’t have blown a fuse. Are your mains IEC cable ends fully plugged in?

It could just be that the regulated design of the 250 is more prone to the effects of being pushed hard than its lesser siblings. Instead of giving up it just keeps on going, potentially until it overheats. What you really need, of course, is a nice fan cooled 300!

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Are you sure the fuse blew? If a NAP250 shuts down then it’s usually the thermal trip cutting in - it’s a regulated amp so it has to work really hard as its work load increases as it won’t let things “slide” like an unregulated amp would. Switch off and leave it for a bit to cool down and then power up again. All should be fine.

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HI Richard

I’m assuming it was the fuse - the amp was really hot, I couldn’t keep by hand on it for more than 5 seconds, so I unplugged everything.

Do you still suggest I try turning everything back on ?

What do you think caused it ?



If the amp was really hot then it was probably just the thermal trip - the casework is the heatsink. Yup, try turning it back on now it has probably cooled down.


If it’s a blown fuse then nothing will happen when you turn it back on.

If it’s the thermal cut-out then it should work as normal once it has cooled down.

I have an olive 250 which has cut out once. Check there is enough ventilation above the amp (i.e. don’t directly stack). I have a small external fan available if I get tempted to turn up the wick for an extended period.

Page E7 of the Amps Manual informs (see link below).

In simple terms, it probably got too hot and shut down (as it is supposed to do) - unlikely to have blown the case fuse.

It may just have been the music combo played but playing at Noon on the dial in to a 250 from a (higher output) digital/tuner source usually means very loud – and you would be stressing the 250.

Power Amplifiers Reference English Issue 2B.pdf (

The OP says " the fuse blew".

First things first, how do you know.?No noise does not equal blown fuse. If however, you have removed the fuse and confirmed it’s blown, then it is blown.

If the thermal trip kicked in, it should be cool by now?

He unplugged it. If it’s not cool now it’s probably time to call the fire brigade :smiley:


We’ve not heard back from the OP in 3 hrs or so. Fuse or just thermal cut out?

Well it’s now switched back on and working - so thermal cut out, not fuse.

To my ears the 250 dr starts to distort ar around 1.00 - 2.00 o’clock and controls my ATC 40’s at 12.00 whilst everything is musical - doesn’t really explain why the amp got so hot after playing at 12.00 for a couple of hours- starting to regret not going for the active ATC’s …

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At those levels the amp is working very hard. If that’s what you do regularly it may not be the best choice for you. How’s your hearing?!


The 250 has quite a bit of muscle but no cooling fans, so it is more prone to this issue than other Naim power amps. A couple of hours at full tilt sounds about right to me, to get it hot and bothered that is.

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Having the dial at 12 should be loud AF! I haven’t heard of too many on here who crank it to that level.

What’s your digital source? I’m wondering if you have it set to a really low output voltage.

Ha ha , I rarely have a private disco , too much booze to include Red Bull…


What length are your speaker cables? Is it Naim cable?

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I’ve got 75db at around 9 o’clock. You must be running past 100dB…:scream:


NAC A5 - equals lengths circa 4 m long , all naim gear on good stand , so plenty of ventilation

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You say you’ve played the system with similar volume settings before - same kind of music or different?

I assume this was via your streamer with a fixed volume output, though the programme content might have been at a much higher level than previous listening sessions. It drives me round the bend when I crank the Nova up to a reasonable level when viewing YouTube music videos, then adverts arrive at a much higher level (same with TV) - I really wish this practice was banned and that broadcasters aimed for a levelled output volume though some might argue it could affect SQ.

Difficult to know I suppose especially after a bit of booze which is often a precursor to ‘accidents’ when it come to hi-fi if I’m anything to go by!