Get rid of speaker thump NAP

Hello everyone,
I bought some time ago an used NAP 200. I’m very pleased with the sound of this unit. But as You know for shure, it can make a pretty loud thump when turning on. Well it was very annoying for me, so I started to look for a solution. And I found one. I bought a small speaker control unit, that can turn off the speaker signal completly.

It’s a simple box, that comes without power supply. It’s small and lightweight. And it get rid of any thump coming from the NAP :slight_smile:

Adding a box such as this is really not a good idea when dealing with high quality hifi. Your lovely signal is going through a cheap and nasty box that really won’t help. The best solution is simply to leave the amplifier switched on, which is how it’s designed to be used.


…or just turn the volume all the way down before turning off and then back on again.

Agree with HH just leave it on…


Same here, leave it on, and either mute or turn volume down

Turning the volume down on the pre won’t help with the NAP thump, I don’t think. But yeah, leave it on :slight_smile:

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…if the volume is all the way down, you would need your ear up against the speakers to hear the thump.

Sorry, how does the volume pot affect the thump output of the NAP200? Is it when it feeds the NAC? My 300 surely thumps even with the volume down

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With the volume on my 82 turned right down, I turn on a 250, and the left hand sibble thumps. I then turn on the second 250, and the right hand sibble thumps.

It’s called inrush current. :slight_smile:

…you have lost me. The person is annoyed by the noise being emmited from the speaker. Turning down the volume stops the loud noise.

My 200 will also thump when turned on (or off) even with the volume down. In fact when turning it off (if we go away for a few days or in case of thunder coming) the thump is so pronounced that I prefer to disconnect the speaker cables at the speaker end first.

He is annoyed by the thump that the NAP200 makes when turning it on. The pre is upstream of that. I don’t understand why the volume pot of the pre affects a sound made by the NAP. The volume pot on my 252 certainly does not affect the thump made by the 300.

(If he was annoyed by thumps made by units upstream from the NAP, like a NAC, the easy solution would be to switch on the NAP after the NAC like the manual says)

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if your power amp(s) are off then when you turn them on there is a surge of current drawn from the mains as the big capacitors (mostly, but does include all the smaller ones as well) charge up from empty. So for a very short period of time (measured in tens of milliseconds) the current drawn from the mains is much greater than the “normal” operating current. it is that current spike that results in the thump.

In my working life, we used to perform many measurements of inrush currents (and indeed outrush on switch off) on our spaceflight hardware.

I understand that a noise is produced by the Power amp when turned on. I have always just turned down the volume and the thump sound from the speakers is reduced. I believe my dealer told me years ago to turn down volume when shutting down and starting up the system years ago.

I like the thump from my 300s as it sends a signal to the SL2s it’s time for business :grin:

My 300s are always on so maybe twice a year I hear the thump no big deal.

Volume low or high on the 282 makes no difference to how loud the thump is.

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If you start with the sources and NAC, and wait 30 secs or so until after pre comes online (or however long the 282 takes), and only then switch on the NAP, I’d expect any turn-on sounds to come from the NAP, unless the NAP somehow affects the NAC over a cable.

From the Amplifiers Manual:


… I guess I have adequately demonstrated what I ‘don’t know’ could not fill the ever expanding universe.

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A burden that we all carry :slight_smile:

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Recapping your amp, if this is due, might partially address your issue.

I’m not sure why this seems to be a problem. It won’t harm the speakers. Naim amps don’t have output relays so unlike others that mute the speaker outputs for a few seconds whilst the amp stabilises on powering up, you get a switch on ‘thump’.


Why not leave it on 24/24. We all do that. Only switching off when on holidays or when there are thunderstorms.