hi, i have cb amps and power supplies that have all been serviced in the last five years that i leave on all the time, usually in four or five month stints and switch them off when i go away for more than a week. When i switch back on it takes about three days to sound good again which is fine but the thing is it sounds a fair bit better than before the switch off, i know im the big variable in this scenario but it raises a few questions for me
is there a reason why powering off seems to refresh the sound?
is there a length of time best to power off for so things fully discharge?
are there any recommendations for how often to turn off?
i might power down every two months, what do you think?
would like to hear what others do, thanks,paul
I agree. I think I’ve found the same. Don’t need to switch off for long - 10 or 20 minutes is enough, but it does seem to freshen up the sound a bit for me when done once a week or so. It takes maybe 30 minutes to get back to best sound after switch off? I wouldn’t say it’s a dramatic difference though.
Bear in mind that human ears are not constant - hearing varies, sometimes better than others sometimes worse. also of possible significance is that memory of sound is not precise. And of course when you have not been enjoying your system for a while, it seems only natural to revel in it when you return to it.
I’ve been doing the power cycle thing with my Naim setup for as long as I can remember. The procedure is to turn everything off, starting at the power amp(s) and ending at the source end, and leave them off for no more than a few minutes. Then turn them back on in the same sequence, taking care to leave 30 seconds or so between power supplies, as they draw a lot of juice at switch-on, and there’s a risk you might blow one of their fuses if multiple boxes are drawing that initial current at the same time.
I arrived at my current routine through trial and error. I’ve found that an interval of four to six weeks is optimal i.e. often enough that there’s a noticeable freshening of the sound, but not so often that you’re power cycling needlessly often and possibly putting needless stress on the internals.
Specifics aside, I’ve found that a periodic cycle, considering that it’s free, takes no effort and only a few minutes, is one of the best tweaks out there.
Also remember that mood affects the enjoyment perceived very much. This mixed with poor audio memory really makes me question my ability to be a good instrument of finding these differences over time.
PA User manual says “Better and more consistent performance will be achieved if the system is left switched on for long periods.”.
Older manuals used to say something about some people preferring to leave the preamp power supply on permanently as it can take several hours for things to properly warm up. Can’t find the original text.
I’ve always Interpreted this as do what works best for you. It’s not difficult to work out a regime with our own kit by trial and error but it’s a pain where the power switch is on the back. Personally I’m a bit lazy and leave everything on.
However! He says in exclamation. I’ve got myself embroiled in a debate about service intervals and capacitors being rated for number of hours at a certain temperature rather than on/off cycles. The claim is that if you leave stuff on 24/7 that it will need servicing a lot sooner than recommended. Now a power amp at rest will be relatively low temperature compared to normal listening volume temperatures but the argument is quite compelling. Not to derail the thread but would be interested in any thoughts or pointer to threads discussing this. I cant find any on this specific subject.
The transformers naim use are sensitive to DC on the grid and can get saturated not providing their best performance. Turning the system off/on will reset this offset.
Lot to read on this.
“Adding DC current to any winding will add flux in one direction approaching saturation and when AC magnetizing current tries to induct more flux the core becomes saturated, the magnetizing current will make a resistive drop on primary winding to compensate, the hum will rise, the secondary AC will be distorted (clipped) and the power dissipated in heat may burn the primary.”
“What happens: When the primary winding has excessive applied voltage, flux in the core may reach the saturation levels during peak moments of the AC sine wave cycle. And hence, voltage induced in the secondary will not remain sinusoidal anymore, creating harmonics in the secondary winding output. The presence of harmonics causes overheating, power loss, reduced efficiency and shortened lifespan of the devices.”
I rang Naim to ask about system being on all the time and they basically said that it’s fine to turn off and leave off when not in use. The guy on the phone said basically that some of the transformers take upto 3 hours to warm up. So as long as you turn it on a few hours before listening you should be good to go at optimal sound. He did say however that the capacitors would last longer if left on, but if turning on / off still way longer than the gap between recommended services.
That has always been my understanding re capacitors generally, the design life being at the specified maximum temperature rating printed on the casing, at least for electrolytics (typically 85C, though I’ve also seen 105C or 125C) and the cooler they run the longer their life. Interestingly I used to have a Musical Fidelity P270 power amp, which being heavily biased into class A ran hot when on regardless of whether playing music (external case temperature about 60C, so hotter inside). When it was about 25 years old I sent it to MF for a service, thinking it could probably do with a recap - yet they didn’t replace the main reservoir capacitors (rated at only 85C) as they tested within spec, though they replaced a few others.
Perhaps this is a natural extension of the “Windows Phenomenon” Graham🤷🏻♂️
If you don’t regularly power cycle a Windows machine, it looses the ability to manage resources and its caches get all full up of leftover “stuff”.
Perhaps people are carrying this philosophy forward to technology in general.
Isn’t it the first question any Customer Service agent asks if technology is involved…”have you turned it off and on again?”
Just had to power cycle my ND555 twice to get it to play. There was an error message on its screen this morning, it was working fine last night for TV sound. Putting it in standby and back cleared the message but no sound when I tried to stream. Checked output mode hadn’t mysteriously changed, it hadn’t, so power cycled but the app couldn’t find it even after force closing and restarting the app. A second power cycle sorted it.
When I had an ND5XS I took to rebooting it every month or two, because I found that otherwise similar happened. But then, the rendering end of a streamer, even the most expensive ones like ND555, is simply a computer, albeit dedicated, optimised and kitted with specialist interfaces etc.
Amps on the other hand aren’t computers and don’t have the memories that fill up, so no parallel there.
Ah, but Windows stuff doesn’t affect me, as I’m an Apple user through and through, and have been ever since the first iPhones came out. At the time, I lived next to a married couple who worked as industrial designers, and they would not give house room to anything Windows-related. That resonated with me, as Steve Jobs was clearly immeasurably more cool than Bill Gates!
I used to have to use Windows at work, until I took early retirement over 20 years ago, and that was extraordinarily clunky stuff compared to Apple.
Actually, before Windows, we used to have a system called Wang (I kid you not, folks!), operated by specially trained ladies in a huge room. I remember being asked for the first time, as a very junior trainee solicitor, to ‘take something to the Wang Room’, and thinking that I must have done something very wrong (or at least unprofessional).