Why No Power Button on Some Phono Stages?

I am upgrading my phono stage, and several of the ones I have shortlisted do not have a power switch/on-off button.

Why is this? Is the user supposed to keep it powered up all the time, or manually unplug the power each time?

I know certain electronics are supposed to have better sound once they have reached thermal equilibrium, but that doesn't mean I want to keep it powered up 24/7.

Switching the phono stage power off from the power strip is a PIA, as it would switch all of my other components off, and I'd lose by tuner settings.

I want to choose the phono stage by sound quality, but an on/off switch is a major convenience factor for me. Why do some manufacturers leave it off?
IMO, most electronics sound better after warm up and they will last longer without the turn on surge (if heat build up is not an issue like in a preamp).

In the case of SS phono preamps the current draw is tiny so there is little reason to turn it off.
Look at it this way...
The doorbell on your front door always stays lit up, and its transformer always has current going to it. Should you be concerned?
SS is best when it is left on 24/7, the designer knows this, hence the lack of a power switch.
I keep everything that doesn't have a tube on all the time, including the power supply for my turntable. I notice that when I turn things off for vacation, it takes a day or two for thing to go back to sounding their best.
A Solid State phono preamp sounds far better when left on all the time. On our Liberty B2B-1 I decided to put a power switch on the back of the unit should one decide to turn it off between listening sessions, it draws only about 25W when powered up. I recommend leaving it on 24/7 for best sound quality.

On our BIG Olympia Preamplifiers and Phono Stages there is no power switch they are designed to be left on 24/7.

In my own system I leave the front end's on 24/7 while turning of the power amps when not in use.

My favorite story on this subject was a gentleman from the San Francisco area whom bought a set of our Whitney amplifiers sometime in the late 90's. In 2008/9 he was visiting someone down here in San Diego and asked if he could bring them by for a check up. He brought them by on a Saturday and I gave them a check over and they measured / performed like the day they left our shop. The guy had never turned off these amps in 12 + years other than the occasional power outage.

Good Listening

The power supply for my turntable is the only thing in my system I leave on 24/7. My phonostage is a tube one, which I manually unplug every time. This is not at all unusual.
It takes substantially less play time than stand-by to worm-up. My area is vulnerable to devastating surges so my equipment is always OFF when not played. It takes one full album to play (near 40m) and wormup of Musical Fidelity XPS and pretty much the rest of system is complete. Do home errands while worm-up tunes are playing. They still sound great. I shut down my system or turn on with single button of Furman conditioner and care less about power switch on my phonostage.
At last we discovered some advantage of the tube amps:
one can turn them off.
So, you want to choose a phono stage for sound quality, but you don't want to leave it on to get the best sound.
Thanks for all of your responses. Yes, I do seek sound quality, but I don't want to leave uneccessary devices on when I am out of the house for several days, often weeks at a time.

While I do agree that it's optimal to listen to components when they are at operating temperature, I would like the option of turning off a device easily when I choose to...
If you want to turn it off, buy one with a power switch.
Most do not have a power switch for the reasons already mentioned.
I have a friend who unplugs everything when she leaves the house. Crazy IMO, but hey, it is her house.
My tube preamps are on permanently. No issues. Every now and then I turn them off for a day or 2 to discharge the power supply caps and ensure there is no behavioural memory imprinted into the power supply caps.
Power supply caps with behavioural memory...
I turn my doorbell off when I leave the house. It doesn't seem to have any effect on the sound.
"While I do agree that it's optimal to listen to components when they are at operating temperature, I would like the option of turning off a device easily when I choose to..."

Plan on several days for optimal sound with solid state devices.
Several days? That's just silly...turn off everything when you're not around, or at least never admit that you leave things on, as these days that's simply lame. Really.
A point that I don't think has been mentioned yet is that depending on the specific design leaving it on all the time might result in greater long-term reliability than turning it on and off, especially if that is done frequently, as a result of reduced thermal cycling.

I use the phono section of a vintage Mark Levinson ML-1 preamplifier as my phono stage. The ML-1 has no power switch. Although I am not its original owner I know that it has been powered up for essentially all of the past 35 years, and its phono section works as new. (Its line stage, which I do not use, did develop a problem a few years ago after being powered up for 30+ years).

However if you do want to turn off a phono stage having no power switch, without turning off power to your tuner or other components, just get a power strip (one that is just a power strip with a switch but includes no filtering or conditioning) and plug its power cord into one of the outlets on your existing strip or conditioner. This Hammond model would be a good choice, if its physical size is acceptable to you.

Some folks might assert that doing that would adversely affect sonics, but IMO any such claims would be speculative, technically unsupportable, and unlikely to be based on experience doing the same thing with the same or similar equipment.

-- Al
What Al said.
I nearly never turn off the solid state components in my audio system. The OP did not say whether the phono stages he is considering are solid state or tube type (or maybe it came out in subsequent discussion which I have not read). The AV receiver in my home theater system has never been shut down since new (about 6 years).

However, most of my gear is tube type, and I do shut down all that stuff between listening sessions, even though I know that turn-on places certain stresses on tubes and the components that feed them.
Dear Czarivey, I don't want to frighten you, but if you are really concerned about destructive power surges due to lightning, you should not only turn off but unplug as well. (You do not say what is the source of the "devastating surges".) A lightning bolt does not respect a power switch.

Dover, I share Czarivey's dismay. What do you mean by "behavioural memory" of a power supply capacitor, or was that just an attempt at humor? If the latter, it worked.
Because most know they sound better when on all the time, too small to cause a fire and the extra 1$ a year it costs ain't gonna break anyone or hurt the North Pole.
IMHO though, anyone who goes away and leaves tube gear on is a fool.
Definitely, Lewm, I forgot to mention that it's being unplugged from the wall.The sources are various: unstable main transformer, winds and devastating lightning bolts.
Lewm -
Memory distortion in audio components, ie resistors and capacitors, is recognised by many now. A common example that some people may be aware of is batteries. If you keep recharging a battery before it is discharged fully, it can form a "memory" whereupon it wont work any more when it reaches that point that you kept recharging it, whereas if you completely run the battery down before recharging, then it will work at all levels.
I run tube preamps where the operating voltages are quite conservative and therefore can be left on all the time.
What I am saying is that if I dont discharge the power supply completely from time to time then those power supply electrolytics will form a memory ( similar to the battery example ) as they have never been fully discharged, or even overcharged on turn on.
Another way of thinking about this cycling, is degaussing your cartridge.
And the answer is yes, I hear a freshening up of the sound when I turn off the components for a day or so.
Dover, How do you discharge PS caps? Turning off for day or 2 may not do the trick and still keep'em charged. It's highly recommended regardless of unit being turned on or off to discharge caps with 1mOhm resistor before any 'surgery' on electronic equipment for certain reason and if you want to verify it, you can (certainly with your own health risk) touch terminals of your power supply caps just to verify and test the information you currently believe into.
As to sound differences, you're simply listening to the 'colder' rig than one was running for a month 24/7. Speaking of electronic components, normal operating temperature is very important to have specified parameters, but excess of temperature can also be even more destructive. In solid state electronics the vibrations against heat sinks will cause loss of integrity and certainly higher running temperatures. In tube electronics in general LOTS of components exposed to the hot running temperatures. It also tells that turning off even solid state devices, will prolong length of good performance.
If you keep recharging a battery before it is discharged fully, it can form a "memory" whereupon it wont work any more when it reaches that point that you kept recharging it, whereas if you completely run the battery down before recharging, then it will work at all levels.
Can you specify what kind of battery has such phenomenal capabilities?