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 ?
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!
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.
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.
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 …
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.
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!