Fan noise on Nap500 DR

Had my Nap 500 now for 5 months and only in last 2 weeks I have heard the fan kick in when played at moderate volumes. Even at 9 or 10 o’clock positions on the pre amp, the noise of the fan is pretty loud.
Has anyone else had this issue. Sent a video to my dealer and he says it may need to back. I haven’t noticed any change in sound quality

My 500DR is always silent, even after long sessions. Your Sopra 2 shouldn’t be that demanding. I would hear the fan on my 300DR when played long and loud but it was only for a short time.

Sounds like it has an issue that is not effecting sound but I would take it straight to your dealer for investigation.

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Never heard the fan of my 500 switch on in over 10 years of enjoyment

Could it be dusty inside? Do you have animals possibly?

I notice the fan of my 500 DR after listening at higher volumes (10 o‘clock and more) - but only after stopping the music, when it is quiet in the room.

I think that there could also be a problem with the mechanics of your fan. So it is a good idea to contact your dealer.

The fan’s never kicked in on mine either, even in moments of tremendous sustained exaggeration.

Under normal use conditions even at modest volumes my 500 fan never comes on except perhaps when we are experiencing a heatwave… rare in the UK!

However I had an issue with my 500 fan running a while back. It went back to Salisbury and no fault was found so it had had to be something in my house causing it. After much trial and error switching appliances on and off methodically I identified the cause to be the power supply to my PC monitor that had gone noisy even though the system is on its on spur and not the house ring main. I bought a new power supply and the problem instantly went away. So it might be worth checking if something in your house is causing the issue.

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I haven’t yet got it back to the delear but…

Solution !

I think I have fixed my problem. I have a REL sub connected to the NAP 500 with the usual 3 wires ( high level connection), red, black and yellow, I also have the my Marantz surround amp (AV out) connected to the 552 by way of one phono connection for the front 2 speakers and also a low level connection of the Marantz to the sub)

A few weeks ago I did think this all started when I accidentally dislodged the red cable from the Rel sub going into the positive Right channel speaker terminal of the Nap 500. I thought I had checked this and tried even switching the sub off, but the fan noise persisted

Watching a movie last night and the NAP 500 was blowing away, loudly (despite the front speakers not working very hard)
At the end of the movie I decided to remove one of the phono inputs from the AV output of the Marantz going into my 552…
Hey presto the fan immediately stopped… and started again if I plugged it back in. With it out, I did notice that the sub was humming. Put the phono back in and the humming stopped
Long and short I decided to disconnect amp 552 and 555 and 500 and put it all back together
So far so good and all working ok, no fan, no hum from sub.
I think the problem may have been my connections of the REL sub to the amp and interacting the the phono input to the 552 from the AV output of the Marantz amp

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I am happy that you have found the cause of the problem. Another case of an external factor causing the fan to come on rather than any internal fault.

This is useful information for any future problems encountered by forum members regarding fans running.

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You may want to check this is correct with Naim / REL. The NAP500 is a bridged amp so the black wire to the Sub shouldn’t be connected.

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There is an inherent issue when connecting many types of sub via the high level input when using a NAP500 (and this definitely applies in the case of RELs).

The 500 is a bridge mode amplifier, and hence there is no 0V / ground plane at the speaker terminals. There also isn’t a specific 0V ground plane terminal provided to help with this type of connection either.
This doesn’t make it impossible, but it does make problems more likely when using the high level connection.

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Correction its LFE not low level from Marantz to Sub

Thanks for replies. I had the red wire connected to L positive terminal and the yellow to the right. The black was on L neg. Rel say that the Red should be on the R, Yellow on Left and black on either neg

So I just changed it, as mine were wrong way round and the fan noise started again on power up. once again, remove av phono input ab it went. Only seemed to be a problem when sub was connected and on. Now I have powered all down , diconnected sub av from both ends, reconnected and seems fine again. A grounding issue ?

Do I need to disconnect black cable ?

James is correct, connecting a sub to a bridged amp like the 500 is different to the standard Rel high level connection. I suspect this would be stressing your 500, and possibly causing it to run hot.

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You will also be further stressing the 500 by connecting the sub cable to its output sockets if I have understood your description. Better to connect at the speaker end as per Naim’s recommendation, for the same reason that choosing a compatible loudspeaker cable is important with their power amp output design.

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It had worked for months with no problems with all three cables connected. I’ll ask dealer next week

All seems fine again. Amp never gets hot but somehow the sub (high level) or av/ sub (phono connection and LFE) must be causing the issue

Just need to clarify how to correctly connect sub

Ok, so connect only to one speaker ? that mean both red and yellow to pos terminal and black to neg terminal

You normally use a split cable so that you connect to both speakers.

In your profile you say you added the sub for “fun”, looks like you’re having some.

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Ha . I’ll see how it goes today not that the fan has stopped