If you mean ON as in fully operational ... a bit of heat.
If you mean ON but in standby ... none.
OFF to me means OFF, drawing NO current from the plug.
And if an SMPS supply is so unstable as to be handled with feathers, its got no place in anything I own.
I've also stated in previous postings about the "old school reliability" of linear supplies, including standby supplies.
I just don't dig stuff that is so badly engineered, particularly most of the crap made these days.
Besides, longevity of things like capacitors is extended when totally powered down when not in use.
Okay, I get that you don't like Switching Power Supplies.
I'm just trying to answer this guy's question.
Thank you.
As I've been telling you half a dozen times already...
I use these things every day.
Leaving it on hurts nothing.
It is turning the ac on and off or unplugging from the supply all the time that shortens their lifetimes.
I wonder... what part of this is everyone having a problem with?
Almost nothing is actually off when "off" these days. This is very obvious when you ask how your preamp/amp/dac/tv/dvd/cd... can see it's remote control while "off". Of course there is still an active power supply in there.
As for lifetime, ask yourself... Do you turn off your router, modem, desk phone, clock, etc, when you go to bed at night or when you go out? These things are running on SMPS wall warts, under load, for years and years without a single incident. In fact the little power supplies most often outlive the devices they are powering... I have a drawer full of them.
So, why, suddenly, when the question is Audio does this become such a crucial topic of debate? Why is it unsafe to leave the external SMPS for a mini-amp on when we don't even give a second thought to all the other ones we use?
As I mentioned earlier, most computer techs are well aware of the problem of current inrushes destroying the primary rectifiers in PC power supplies. These inrush currents can get pretty close to 20 amps for a fraction of a second. The rectifier diodes can handle it only a limited number of times. Hence the general advice to leave the "baby sitter" switch on the back turned on all the time to limit the number of wild surges of current, prolonging the lifetime of the power supply.
Why is it the right thing to do with so many other devices... but suddenly so wrong with Audio equipment?
People talking about audiophoolery... there it is... "Oh it's fine for your modem and router but don't even think about it for your dac, preamp or amp"... really???
For our very confused friend...
Hook up your gear, put on some good music, sit back and enjoy. Turn it off from the button on the amp or remote when done... Next time, just push the button and enjoy your music all over again.
Almost nothing is actually off when "off" these days. This is very obvious when you ask how your preamp/amp/dac/tv/dvd/cd... can see it's remote control while "off". Of course there is still an active power supply in there.
As for lifetime, ask yourself... Do you turn off your router, modem, desk phone, clock, etc, when you go to bed at night or when you go out? These things are running on SMPS wall warts, under load, for years and years without a single incident. In fact the little power supplies most often outlive the devices they are powering... I have a drawer full of them.
So, why, suddenly, when the question is Audio does this become such a crucial topic of debate? Why is it unsafe to leave the external SMPS for a mini-amp on when we don't even give a second thought to all the other ones we use?
As I mentioned earlier, most computer techs are well aware of the problem of current inrushes destroying the primary rectifiers in PC power supplies. These inrush currents can get pretty close to 20 amps for a fraction of a second. The rectifier diodes can handle it only a limited number of times. Hence the general advice to leave the "baby sitter" switch on the back turned on all the time to limit the number of wild surges of current, prolonging the lifetime of the power supply.
Why is it the right thing to do with so many other devices... but suddenly so wrong with Audio equipment?
People talking about audiophoolery... there it is... "Oh it's fine for your modem and router but don't even think about it for your dac, preamp or amp"... really???
For our very confused friend...
Hook up your gear, put on some good music, sit back and enjoy. Turn it off from the button on the amp or remote when done... Next time, just push the button and enjoy your music all over again.
You've nailed it. We all yet have too much gear that we can't turn off, especially IT and telecommunications devices. But does this really legitimate to power on or leaving in stand-by other equipment that surely can be switched off when not in use? For instance I run switchable multiple outlet extensions for my HiFi and computer gear without feeling too uncomfortable. Helps me save a lot of money and, last but not least, carbon dioxide.
Best regards!
Best regards!
I can see Douglas's argument about turn-on surges, but that leaves me with only one conclusion....plain and simple.
Poor design, affecting reliability, something that obviously needs addressing.
One should NOT have to worry about such issues with any equipment, regardless of how it is powered, be it SMPS, or Linear supplies.
If a person feels that they want to shut something off..... completely, they should be able to, without some built-in design failure compromising reliablity.
Build it properly in the first place, and you won't be having issues later.
Yet, strangely enough, 100% reliable for years on end if used as intended.
Yes, most of the SMPS bricks have current limiting ... on their outputs. Nothing protects that diode bridge right across the line, dumping into the high voltage primary caps.
Ummm... I don't know what your electricity rates are like... but in Canada leaving both my PCs with their mini-amps hooked up and in standby for a year would cost me less than $12.00
Diodes, when used properly, in a properly designed circuit, all have surge capabilities.
This is common knowledge, and must be considered by the designer for "worst case" operation - including repeated power down/up situations.
Anything else is foolish to even consider doing, an electrical hazard, and surely not approved by agencies (underwriters labs/UL) governing specific electrical codes.
If you're suggesting that products have such "delicate" or fragile diodes or any power supply components, then these products are destined for the recall bullentins or the trash bin, whichever is easier.
Being a long time semi-retired decades-old service tech, I've seen my share of lousy products, some of which should never have been sold to the public.