The B&W CM10 according to a quick check are rated at 8 ohms and 3.1 minimum, recommended 30-200 watts. Given their market segment, I don’t expect them to be very demanding (though haven’t looked in detail). My money is on speaker cables.
The Nova has an awful lot of electronics packed into the box, and digital stuff often runs quite hot, which won’t be helping the amp when it’s working hard.
The case is designed to act as a heatsink, so improving the airflow over it will certainly help. The higher end Naim power amps (135, 300, 500) are fan cooled, although the fans tend only to kick in when they are working hard, so the noise is likely to be drowned out by the music.
If you can improve things passively by increasing air space around the box it might help. Otherwise I think a fan would be a good idea.
Another option you could consider is a separate power amp if you have room for it, but of course that’s going to cost you.
Stereophile did note that the Nova shutoff due to overtemperature when they were testing. Not sure how realistic the test was but it may shed some light.
Good find and somewhat surprising, the test does not seem to be ridiculously stressful. Though he does not seem to say which cables he used at this point. At the end of the test he mentions:
Speaker: AudioQuest Castle Rock, Auditorium 23, Tellurium Q Black.
The AQ does not seem very appropriate (it is a bi-wiring cable within a single strand), even if the Unitis are less critical; if it was a Classic, I would say don’t use it. I don’t know the second one, the Tellurium should be OK by all accounts.
As should the WH of the OP, and I really think it should be possible to do what he is doing without it shutting off. (Assuming normal environment)
I use my Nova as a streamer preamp into a separate power amp and mostly it runs cool. But sometimes the left side of the case gets really hot (about 43 deg C) even when no music is playing. The only way to cool it down is to turn it off for a while and then it may be another week or two before it gets that hot again. I don’t have server mode turned on. My best guess so far is that it gets hot if I have a upnp play queue stopped, presumably because the streamer and DAC sections are primed to restart playing the music.
My Nova just overheated, start of the 3rd album. I was driving it loud, like 70-90 with the setting at factory 85%…I just bought Audioquest type 5 cables…10’…
I just switched. I’ll let it cool and see how that works. But, mine is sitting on a heavy wood shelf and I have saws and drills! So it’s going to be ventilated…unless I decide to swap it with…lol
Many AQ speaker cables are constructed in ways making them problematic for Naim units, such as being internally bi-wired, although Unitis are less picky. The AQ Type 5 has “Balanced Star-Quad Geometry” according to the AQ website. According to https://en.wikipedia.org/wiki/Star_quad_cable, this results in high capacitance. As AQ does not publish electrical specs, it is difficult to tell if it is suitable cable. I would try with a non-fancy one and see if the overheating goes away
Oh wow this is weird, I have absolutely thrashed Novas during demos at a dealers and not once noticed case temperature issues. Perhaps you have elevated ambient temperatures compared to the UK?
Btw my SuperUniti seems to get warm if left at idle, I.e. no music playing compared to when giving it some, but never what I would describe as ‘Hot to touch’.
Naim NACA5, it’s the safest bet but I have a classic amp which is more critical re. speaker cables. The Unitis are more tolerant but there are still cables that are a poor fit.