I have a question. I am told by the Focal/Naim distributor in my country that you should turn on all equipment except the NAP 250DR, then after a minute or so, turn the amp on. To close, amp should be first, then the rest of the equipment after a few seconds.
I am using a switched power bar for all equipment (so on/off switches can stay on), except for the amp. Is it recommended to have a different switched power bar for the amp to avoid the wear and tear of the on/off switch of the amp as well?
I wouldnāt worry about that at all. Whilst I donāt have specific knowledge of the switches Naim install in their amps, Iād be extremely surprised if they arenāt robust enough for decades of daily operation, though of course statistically the odd one might fail after only 1 usesā¦
When we powered up spacecraft, the sequence was always front to back. The theory being to stabilise the lower power equipments before firing up the high power stuff. Similarly, on power down, high power stuff off first then low power.
The idea was always to avoid presenting an open-circuit input to the high power amps.
So I suppose, Iāve always done it this way for hifi.
I always observed the correct power up/power down sequence when I had a Naim Classic separates system (not so important with New Classic, apparently), but on the odd occasion when we had an unexpected power cut, the system never failed to function after the power came back on.
Re sequence, it is very simple: turn power amp on last (and off first,)ā order of other things is less critical, and can all be together. The reason is simple: you donāt want any switching transients from earlier kit to create a large pulse to the speakers with real potential to cause damage, easily avoided if the poweramp driving the speakers is left off untill everything else is on.
If you are using a switch power bar - you donāt say which country you live, which is always useful for such a question - then best to use the power switch on the NAP250.
So with NAP āoffā switch on power bar, then wait a short while, then switch on the NAP.
End of session, do the reverse.
I have a NAP250, which can, as others have mentioned, can trip the breaker when powered on.
As with most others on this thread, I follow the recommended power-up and power-down sequence. I get the need to stagger switching on the power supplies, but Iām not aware of a recommended interval.
There have been several power outages down the years where all the equipment has come back on at once, but no onboard fuse has ever tripped. Iām not inclined to push my luck, though, and I typically give it ten or twenty seconds between switching on each power supply.
I note that, after switching on my 552PS, one of the mute lights remains on for about thirty seconds, then switches itself off, which tells me that everything is stable and ready to go. It seems unnecessary to wait any longer than that.
Switch on surge is just that, a surge at switch-on. With torroidal transformers there is an almost instant extremely high demand that drops almost instantly (called th einrush current, it lasts only a fraction of a second), then you get whatever is the normal maximum unit (PS, amp etc) current as the capacitors start to charge, which reduces over a few seconds and levels out as the normal background current. It is that initial very high pulse, particularly if from multiple devices at the same time, is what trips circuit breakers in the consumer unit or blows fuses in any plugs supplying multiple units. Although it may take from a few seconds to a few tens of seconds to fully charge reservoir capacitors and current drop to working level, just a few seconds is likely to be plenty enough to avoid tripping breakers or blowing fuses.
On the subject of avoiding potentially damaging thumps to speakers, particularly when connecting/disconnecting components: After turning the power amp off as the first step, unless it is known that there are relays at the same time disconnecting the speakers it is prudent to wait a few minutes for capacitors to largely discharge before undertaking said work. (Iām not certain whether if not Naim power amps have such relays? I have in mind not, and certainly not all power amps have them, and can still give full output for a while after switch off.)
Thanks Cory, the same thing happens on my 282, after 30 seconds or so, the mute button comes off and that is when I switch the 250DR on. Thanks for you your comment.
Naim recommend that you use the switches on each device to turn them on and off, so I suggest thatās what you should do. Better still, ditch the switched power strip altogether. Unswitched power strips and wall sockets give better performance.
When I switch my n-SUB off the Naim logo stays illuminated for about a minute after hitting the off button. Iāve never known a unit to take so long to power down, so a minute sounds an about right to me. I think your dealer is correct with their advice.
Thanks for your answer, Chris, could you be so kind as to give me the reference for your claim? Is it written in the different instruction booklets provided with the Naim system and if so, which booklet and what page? The reason I ask is that I saw someone said the on/off switch on his 250 got stuck and the unit had to be serviced to remedy the situation. Years ago, I owned a Quad 33/303 and the volume of the 33 was the on/off switch and after a while, it needed some repair due to wear and tear. To avoid that, many Quad owners used a switched power bar to avoid the wear and tear. That is where my idea of using a switched power bar for my Naim equipment comes from, to avoid on/off switch wear and tear on these units over time. But your explanation makes sense, I just would like to see if you read that somewhere or your source. Thanks again, your answer and upcoming answer are greatly appreciated.
