With vinyl in to a Naim amp (like the SN3) via a standard line-level input, I’ve found to get things loud I would need to go to >11am on the dial, as vinyl outputs are often still ‘lower level’ even if via a phono amp. So a question - what input on the SN3 are you using?
It seems to me that the phono signal input is perhaps too high, in that it’s OK to let the SN3 do the amplification rather than the phono amp.
If you input a high level signal and play loud, the SN3 will be ‘working hard’ (in its performance envelope), hence the heat, as it will only produce a certain level of output in to the 'speakers. Add some unfiltered stuff (as Richard describes) and this makes the SN3 work even harder still.
Too low a gain on the MC will only make it quiet too high and might sound rough but power amps only get trip out hot if met with high resistance at the outward path.
Yes, there is a balance to be struck with matching the inputs optimally for the amp. Is it not the case though that low resistance is the enemy of power amps vis the sharp fall-aways in impedance? And in many 'speakers, this arises when the woofers are asked to work overtime?
Over heating power amps are usually caused by excessive driving loads or resistance on the output.
But a low input will not generate enough signal power to allow the driving side to have enough power to heat unless encountering resistance.
If the input signal is too low it’s not really much different to your system sitting not playing with the volume still up.
I asked a while ago if you could take picture of the solder joins in the banana plugs.
That would help determine connectivity looking at the colour of the joint.
In mechanical terms, there are 3 or 4 hex head machine screws on the bottom that clamp the metal inner chassis (to which the ceramic heat-pads are attached…and the output devices are bolted to these ceramic insulators) to the outer case. These bottom screws thermally couple the outer aluminum case cover (which is substantial at like 5mm-7mm thick of solid aluminum), to the inner metal chassis, through mechanical compression.
If any of these screws are even slightly loose, that would be very bad and could easily cause issues like the OP describes.
NOTE: Absolutely none of these things I have described are user-serviceable. The best course in this case, with available info, is to have this amp serviced by a Naim-authorized dealer or service center.
Just spoke to my dealer, he told me that the obvious reason for the overheating was that the sn3 couldn’t provide the demanding power in certain frequency range (low frequencies in my case) to the Ovators.
So to protect itself from overheating due to it’s inability to drive the speakers in such frequencies it shut down.
Also i checked the woofers if they rumble & not such thing exists even when i cranked the volume up to 11 o’clock.
So the combination of the hungry for power Ovators & the demanding low frequency of the d&b records probably caused the overheating.
I’m not sure whether your Goldnote Phono stage is IEC or RIAA, but it looks quite configurable, in which case try setting it to IEC as this should include the subsonic frequency cut over RIAA and usually cures the subsonic issues I mention in my earlier post above.
Note that you don’t really hear subsonics, but they sap huge amounts of power from the amp and with prolonged play can trigger a shutdown like you experienced.
Something has changed OP says he’s had this setup for four years and this is the first time it’s happened.
Everything works fine until it doesn’t.
I’ve said all along amps don’t get hot until they meet resistance either a bad load or a poor connection.
Good Luck.
That may well be the source of the issue. If you play some vinyl with some subsonic issues - warps, even slight ones are notorious here, but I have a handful that are dead flat but can demonstrate subsonic noise very well - then it can make the amp work very hard, to the point of getting hot and even shutting down. IEC EQ phono stages are much better here than RIAA as IEC includes a subsonic filter. However, note that compliance issues between the cartridge and the tonearm can exacerbate subsonic problems…
@Vaggoz
Hi
Thanks for taking the trouble to post the pictures.
They don’t look good at all it looks like the inner stranding is rather oxidised and the idea of trying to solder screw fit plugs isn’t good.
I don’t like that type of Banana as they don’t seem to retain a tight fit in the socket.
I’m sorry to be so negative but I couldn’t have that at all.
I prefer the proper Naim and Deltron pins they keep their tension much longer and I find they have a more robust surface area contact.
Below is a picture of what properly soldered Naim pins look like for either heatshrinking or for Naim sockets use SA8 plugs.
I use Naim and Deltron the pin arrangement is the same mine below that.
Perhaps this might not cure a problem without closer inspection and hands on but it could only be better.
I totally agree with you, i didn’t like how it looked from day one, but since it performed great with no issues for about 8 months now even at higher volumes i strongly believe this is not the cause of the problem.
Would you believe me if i tell that my dealer has ordered the naim plugs fot the Ovators on August 2023 & the official dealer doesn’t bother to get them even after numerous calls my dealer made to him.
Market in Greece is sh☆t ( excuse my language).
