300DR powering down by itself

Couldn’t find it mentioned, but does it still happen if the speaker cables are completely disconnected ?

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I had the same issue but I use Superlumina speaker cable, so imo this problem is not related to cable.I experienced this “power down “ at low volume only twice this summer in a very hot weather so I think that there was an improper activation of the thermal switch. Now without further action everything’s is working fine even at very low volume.

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As Richard Dane suggests do check that the power switch is ‘latching’ and that the Powerline is engaged fully. As I have had both these problems over the years with the same effect.

Richard

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Sorry to hear it! It’s definitely a bug, not a feature – I leave my system including a 300DR on 24/7, and it sometimes goes several days idle with no input and no issues.

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The fact that the same fault with a new 300 has been reported by two people within a short period of time does tend to suggest there might be a problem…

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Hi,

I tried that today. I unplugged the speaker cables and left it running on a low volume preamp setting for 4 hours and it remained running.

I’m now going to run the system with the speakers cable plugged in at listening volumes and then later turn it down again and see what happens.

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Swapping in another set of speaker cables sounds like the logical next step

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Well, after playing for a couple of hours at listening volumes, it powered down again by itself.

Then after 5 minutes there was a click, then it would power up again.

Then after 5 minutes or so of music again, it would power down again. Then they cycle repeats, 5 minutes - a click and then it powers back up.

I’d give your dealer a call tomorrow and seek advice. If the amp box isn’t warm and the fan isn’t running when it powers down then i suspect the speaker cables aren’t the issue here and it’s related to something false triggering the thermal cut off switch in the power supply box.

The click sounds like something is triggering the protection. Does it do this if no speaker cable or speakers are connected?

My bet is that it’s a faulty unit. Since the loudspeaker cables worked ok with your 250DR, it’s very unlikely indeed to be them, so a waste of effort to try borrowing NAC-A5 cables imho.

Naim should probably pay more attention to production quality control.

Best

David

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He said above that it works fine with no speakers or speaker cables connected. The logical test is to try some naca5. If the problem goes away it’s the cables causing the problem. If it remains, it’s highly likely that the amplifier is faulty in some way.

OK, I’ve had a closer look at the Black Rhodium website and I note that it talks about twisted pair construction. This is possibly not good news because depending on how much it’s twisted this can give a very low inductance, which will potentially upset a traditional Naim amplifier. Unfortunately there doesn’t seem to be any spec for the inductance.

It could be that your NAP250DR was just on the right side of tolerance for this low inductance, but your NAP300DR is just on the wrong side.

I would reiterate the advice to try it with some recommended lengths of NACA5. If it’s fine, you’ve found the problem. If not…

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Any news, NAP300DR working fine now ?

I dropped the 300DR amp and psu back at my dealers on Monday. I was told on Friday morning that they have put in for an Advance Replacement with Naim.

So ampless and waiting.

In the meantime I have bought 2 x 5M of Naim Naca5 professionally terminated with gold plated plugs on the speaker end and NAIM amp connectors on the other.

Slightly surprised your dealer hasn’t loaned you a stand-in amp whilst yours is being replaced?

Hi, they offered me my traded-in 250DR back temporarily. But its a faff to connect to my new 252 and well… just not the same as the 300DR that I can’t now unhear :slight_smile: So I just have to develop patience.

When I heard “twisted speaker cable”, I was a bit concerned as well- and what works with 250DR is not a guarantee for the 300DR.
Has your dealer assisted you in the troubleshooting?
As we haven’t heard of a diagnosed problem, I hope it doesn’t repeat with a fresh 300DR. Good luck

A) I will be using NACA5 so moot
B) Don’t all DR amps have a Zobel network anyway nowadays… so moot as well.

As regards troubleshooting… yes the dealer did a soak test to replicate what I was seeing (also with no cables on). The consensus is that the amp is faulty from Naim.

The DR upgrade has nothing to do with the output stage.