Powering on / off SN2 and HiCap, does order matter?


I’ve recently added a HiCap to power my SN2. Only had it a day or so, but so far it sounds fantastic, much better than I’d expected. Looking forward to the weekend when I can give it a real try out.

It does have a slight transformer hum, which I read here is sometimes the case for Naim PS. Not enough to be a big distraction, but is noticeable if the room is quiet and I sit in the wrong place. When time permits I will play around with its positioning, plug it into a different ring, etc, but for now I was wondering if I can safely switch it off but leave the SN2 on if it does start to bug me. The power switch is far easier to reach than that on the SN2! The manual says to switch it on before an amp, and off after an amp - what are the risks of not following this ?

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The manual is the correct point of reference, ordinarily you’d want to leave the amp and PSU powered on. If for any reason you do turn things off, the external PSU, in your case the HiCap is always first to be powered on and last to be powered off.
Bare in mind turning things on and off frequently will wear out the components quicker than leaving things on all the time.
I leave mine on unless I’m going away for more than a few days or the sky has electricity in it.
If the HiCap is humming first try moving it to a different position. If it’s audible even at a distance I’d suspect DC leaking on to your AC supply.
Others can chip in here with more granular insight, a dedicated mains spur won’t hurt either to keep the transformers isolated from in building noise sources like fridges or dishwashers for example.

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Thanks. I’ll leave it switched on, reckon I can accept the hum. I’m interested in why this is the recommended way of doing it though - is there a risk of damging either unit if done otherwise ?

This is to prevent the switching noise going through the power amp and speakers. If switching off the HiCap only, turn the volume down or mute the SN2 first.

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