Thud or click sound at first activate or de-activate Naim NAC62/NAP140


I am using the Naim NAC-62 and NAP-140. : noise momentarily turns on the naim but after that it disappears and has no effect on music playback, when music is heard, there is no noise or hum at all. clean and normal sound. Is this normal? my friend once said this because in this vintage Naim there is no relay so there is a little click or thud sound, but according to my friend this is natural. Is it true ?

Thank you

Are you turning the power amp on last, and off first? If not that is the correct order. Or am I misunderstanding and allis powered up all the time, in which case what triggers the thump? (If changing or powering up a source, with pre and power amp on, good practice is to drop volume control to zero beforehand.)

Normal, it should last quite short. 10 or 20 sec or so.

Oh and keep them switched on :slight_smile:

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I would say much less than 10 or 20 secs. If it lasts a quarter of a second, then it’s normal.



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It should be short, but can take longer when things need servicing.


yes I turn on and turn off my Naim audio system according to the correct rules where when I turn on, I start turning on the CD Player and finally my NAP-140 power amplifier and vice versa if I turn off my system, I will start turning off my power amplifier and finally the source or CD player

the sound of “duk” lasted for less than 5 seconds, maybe about 3 seconds when I turned on my Naim system as well as when I turned off my Naim system.

wow, if you keep turning it on, do you not love the parts inside Naim, in a sense, their lifespan could be shorter

Could you please describe in more detail what triggers the thump? I.e. what exactly you are doing when it happens?

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I don’t know what triggers it when I turn the Naim NAP-140 on and off, I use the NAC-62 / NAP-140. This happened early when I turned it on and when I turned it off, it only sounded about 2-3 seconds maximum, it looked like the capacitor was charging when turned on and the capacitor was discharging when the NAP-140 was turned off, on some forums and friends’ information. here, this is said to be normal. I don’t know how to solve it, I’m just worried about my speakers

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Ok, so now I think I’m clear: it happens only when you turn the NAP on, not at any other time?

If is perfectly normal with many amps to have a switch-on thump, unless they have a relay that delays connecting the output. From the answers from people presumably directly familiar with the 140 it would seem the 140 doesn’t have such a relay.

according to some Naim users here, by not installing the relay, it will be able to improve the sound quality of this Naim unit itself, especially the NAP-140, what is done so that when it is turned on the 'Duk “sound can not be heard on the speaker, is the selector position in the position” muting "?

Buy a Hicap. Switch on the Hicap and preamp first. Then the power amp. Problem solved.


thanks for the advice

If I buy Hicap:

  • I turned on Hicap first, did I turn on Hicap as soon as I turned on the Pre-Amp NAC-62 too?
  • then I just turned on the NAP-140

both the Hicap and the NAP-140 all need to be plugged in?

Hi Richard, is this sound also happened on Classic Naim like : NAC-122X + NAP-150X ? or do they use protection circuit or relay on NAP-150X ?

thank you

Where you have a power amp powering both itself and a connected pre-amp you will often get a click or thump at switch on. This is because the power amp switches on first fractionally before the pre-amp. The way to avoid this is to switch on the pre-amp first, but you can only do this when the pre-amp has its won dedicated power supply.

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So in other words, even though I use Naim classic like NAC-122X and NAP-150X as long as I don’t use HiCap, then the click / thumb sound when I first start the system or turn off the system will definitely happen?

Essentially, yes (if nit-picking I’d say that a Flatcap would probably be more appropriate partnering a NAC122x and NAP150x). It’s only momentary though and shouldn’t do any harm to anything. And as Naim Naim kit is designed to be left powered up, you won’t have to switch on very often.

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