Danger when disconnecting speaker cables

I have two sets of speakers and also two sets of cables so when I am swapping I may disconnect at the amp side. However this is a bit of a hassle and the rear of my nap 300 is less accessible than the rear of the speakers. I would like to just move the speaker cable from speaker a to speaker b. (Without turning off)

So… I read here on the forum that if negative and positive speaker lead touches your amp might go «up in smoke» - is it really that dangerous? Is there no fuse or protection circuit?

And out of couriosity - what are the consequenses, a 1000 pound repair or having to buy a brand new?

(I do understand that the safest solution is simply to turn it off, and this is what I will do - but again - I am curious. And it seemes like something one would design to be idiot-proof).

There is protection circuitry but as long as you don’t touch the exposed pins together you won’t need it :wink:

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Fuse protection on the output is usually not favoured when you’re after best performance. However, there is protection against short circuit, but it’s not something you should be testing to destruction. Best avoid any situation where you might short the outputs.

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There is no such thing, ever. :grin:


Just switch the Power Amp off, before moving any speaker cables. Simples…

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And if you really can’t switch off, the Naim SA8 speaker connectors make it really easy to unplug and re-plug at the amp end without needing to switch on and off. I trust you are using these at the amp end…?

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I wonder if you would cause any damage when the volume is turned down to ‘0’


I do not use these plugs as the cables are terminated, I do pull negative and pos out at the same time.

And there is not problem turning it off, I do this as well. But if I do back-and-forth testing for a bit I would have thougt turning the 300 on and off several times might stress it more that simply moving the speaker-end of the cables from speaker a to b.

No, it should be fine. Switch off, and allow the caps to discharge fully before switching on again.


Best to be safe. Only today I did a disconnect of the SNAIC 2, to wipe clean the contacts, on my Supercap and forgot to power it off. :scream:
Luckily the NAP250 was already switched off 15 minutes previously. :slightly_smiling_face:

There’s only power and no signal on SNAIC 2 but nonetheless I cringed…

I have always thought any cable carrying power should be handeled more careful that signal. Power is where I would expect to short-circuit or disrupt any power-down prosess.

But maybe this is more on non-naim equipment. When connecting RCA-cables or optical I assume no harm can be done as long as volume is within normal operation.

But yes, better safe than sorry. Easy to make such mistakes, and therefore I thought it also was idiot-proof. Whenever I am at my dealers they seem to never turn anything of regardless of what they are switching around.

Dealers are experienced and do it all the time. RCAs disconnect signal ground first so are riskier than DIN.

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NOT a safe assumption - it may still be possible to create pulse sufficiently strong to damage a speaker. If low level inputs either select a different input, turn volume to zero, or turn power amp off before doing anything with cables (good practice is always to turn volume control to zero after use). If interconnects to power amp, always turn power amp off first.

Aside from being more likely to know what actually causes problems, a mishap requiring repair costs the dealer less than it does you - and the dealer weighs up the risk vs benefit of speed of demo as for her or him time is money.



It’s called hot-patching in pro Audio. It’s bad. Avoid any patches in your active signal chain. Mute, turn volume all the way down, switch inputs, or simply turn the system off (what I do).

My main speakers do double duty in both my audio and AV systems so I swap cables at the speaker end regularly. I’ve never turned the volume down (though, since it’s been mentioned, I might start doing so) and never had any kit go bye-bye.

I thought I heard a short a few years ago, so I made these wooden blocks for the AV speaker cable plugs to sit in when not in use so I could be sure they couldn’t touch:

YM, it should go without saying, MV.



Would have looked nice in aluminium :grinning:

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