Switch amp off when changing cables?

When testing new speakers and unplugging cables from the speaker end is it a good idea to unplug the amp from the mains? Or can one leave the amp in standby mode?

How about when fiddling with interconnects?

I ask because now I’m the proud owner of a Nova, and trying to find a good a speaker match, I am unplugging from the mains each time and being rather more cautious than I used to be with my previous budget integrateds!

If the speaker plugs touch each other, either directly or via any metal surface they touch, it will end badly. Best turn off to be safe.


The OP is a bit ambiguous, the title says “switch off”, the post talks about unplugging the amp from the mains. And it’s about a Nova. Of course, switching off is an unambiguous thing with a classic amp, but is a Nova ever really off when you push the front button? I suppose it’s good enough and turns off the output stage, but for the benefit of the OP it would be good if anyone could say.

Personally, i would recommend unplugging the mains before before changing any cables. But then I am a Chartered Elec. Eng and supposed to know what I’m doing,

OTOH, I have often ignored my own recommendation because, hey, I’m a Chartered Elec. Eng. and I’m supposed to know what I’m doing…

…the last time I ignored myself, it cost me 1100 quid because I blew up the comms boards in two of my Meridian DSP5000 speakers…

But as ever, the choice is yours :smiley: . Just try and avoid sticking your fingers on the one marked Live - coz it hurts!


Yes, sorry it was a bit ambiguous. The question I wanted to ask was whether unplugging from the mains was good practice when making adjustments to speaker cables and interconnects on a Nova.

On the one hand I suppose it’s the safest thing to do for the reasons posted by others but in the back of my mind I am wondering whether the repeated unplugging from the mains (say 3 or 4 times in as many hours) is ok for the components?

If you put it in standby mode, that should be enough as it turns off the main transformer and just keeps the tiny SMPS running, which is only able to keep it discoverable in standby mode. Then again, if server mode is on, the main PSU is still live, and who knows what a software glitch or accidental button press might do. Deep sleep mode might be a safer bet, but if you really want to be sure, perhaps unplugging isn’t such a bad idea.


ALWAYS switch off when changing interconnects, SNAICs etc. However, so long as you’re using Naim SA8 speaker plugs then it’s OK to plug and unplug speaker cable from the amp when powered up.

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My first Naim amp was a 5i, to use with a pair of PMC 23s. The dealer had advised me that as I was using my old biwire spkr cables I should join each pair at each end to use 2 cables into each plug, rather than have spare unused. After carefully making off the ends and checking there were no crossovers I plugged it all in and switched on. Nothing, except a brief flash of the input selector lights. Repeat, same, and no sound. Then I triple checked the spkr cables and found that I had indeed joined +ve to -ve on one channel. I corrected it and it worked brilliantly till it went in as a p/x for a 250.

I suspect that Naim build in protection against such idiocy, but choose not to announce it.

Anyway. In answer to the original question I don’t bother switching things off and on again just to change cables, speaker or otherwise. Volume to zero and care with any loose ends is ok. It occasionally feels that people are too cautious, when the risk is almost zero.

The OP was asking about unplugging at the speaker end, but I guess following your advice and unplugging at the amp end first, then changing the speakers over, would be a safe alternative to pulling the mains plug.

With SA8s it’s probably fairly safe to unplug at the speaker end too although generally it’s not good practice because if the pins fell across say a piece of metal that then bridged them, then the amp would not like it at all! Unplugging them at the amp end, there’s no risk of such an eventuality.

Having witnessed my brother, many years ago, unplugging the cables from my Royd Apex only to drop them onto the metal speaker stands with nasty consequences for my NAP, I can only say that disconnecting something upstream has been my routine ever since.

Despite best intentions, it is very easy to get complacent. I have swapped speaker cables on my SU ‘live’ many times but I did once accidentally, momentarily touch + & - together with the amp on but nothing playing. I think I got away with it, as it still worked on both channels afterwards, but it isn’t worth the risk.

IMO, any minor inconvenience or perceived temporary loss in sound quality due to turning it off, is nothing compared to one channel silenced and faulty followed by a lengthy trip to the repair shop!


Absolutely this. No ifs, no buts.

I would also advise leaving an amp 10-15 mins before turning on again. A short repeated sequence of off/on is just asking for trouble. Patience is required :grinning:

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