When to Poweroff amps and preamps

I apologize if this has been asked before but I haven’t been able to find it.  What is recommended for when to turn off the power to amplifiers and preamps?  What if you’re going to be using the equipment within a day or so...power it off completely, put it on sleep if that’s available, leave it on?  What if you’re not going to use  it for a longer time...a couple of days?  A week?  Are there different recommendations for solid state and tube equipment? I’m interested in both getting the best sound and prolonging the equipment life. 
Solid state, leave on 24/7. Tubes, turn on to warm up 5-20 minutes, turn off when done. Hybrid (DACs that think a tube will make digital listenable) no tube on Earth can do that but hopefully the tubes are cheap because being digital absolutely must be left on.

This is both for sound quality AND longevity. The greatest wear factor with SS is thermal, which is reduced by leaving on. The greatest wear factor with tubes is being on, which is reduced by turning off.

So the moral of the story: buy tubes, buy analog, turn off when done.
MC your priceless, what are you gonna do if you ever hear a Reel to Reel you like. They are easy to like too, I mean REALLY like.. :-) Just sayin'

I'd just like to add, there are a few, SS power amps, you want to shut off.
Class A  SS gear will just run to hot to leave on...Class AB older amps can run on the hot side. It depends on a few things.

Bias setting for one, when idling..It can make a BIG difference, there is a trick or two, to be able to leave the older AB stuff, on.. (for a while)
I have Adcom gear, in one of the shops. LOOK out.. when they are warmed up..VERY good gear if you know what your doing..VERY bad if you don't. Speaker blowing baster$s, if your not careful.

I turn THAT setup off.

UNLESS it's Class Ds, some Gs, or has a stand by, and is a power amp, OFF.

MC did say digital, BUT SS and digital, aren't exclusive. I know what he means. BUT there are THOSE, that will pick it apart.

Ncore amp modules (on), and my current  Mac gear (stand by), I leave on.

Soon though, my C2500 will be fixed, BUT it is both DAC and valves, it gets turned OFF.

The fall/winter/spring, monitor amps will be swapped for valves, (I can hardly wait). ALL the stuff currently stays ON, Three weeks or so, OFF

 Anything with tubes (valves) gets turned off. It's just not safe..

Now that I'm thoroughly, confused, I'll go in the shop and warm up the C20, MC240 (all valves) and a class d Behringer 12K, about 10 minutes of play time... It's a Class D, BUT I disconnected 2 of the three fans and put the last one on a flipper switch. QUIET, at 2 AM, wonderful. I get CLEANER power too. 2-4:30 or so..

Time for the morning walk...and feed the rabbit (Junior)

I'm learning from this post, so will just add to @brownsf question:

If solid state gear is left on, is it best to disengage the speakers (either with a speaker switch button or with a mute button)? If there's an electrical hiccup (not a storm) it might protect the speakers... 

Is that a real consideration or am this a worry about nothing?

millercarbon is correct 2 out of 3

disregard his comments on digital, imo he is right on the other items about turnoff for ss and tubes

the mind is a powerful thing, your beliefs can grossly affect what you perceive
The real SS engineers with good ears put in an effective standby circuit, including hybrids with tubes ( see for example Ayre or Vandersteen M7 HPA )

and of course super engineers like Jim White of Aesthetix also know how to engineer a great sounding FPGA DAC With tubes that also has a standby mode. Of course those who are living in 1985 and incapable of forming new impressions will protest. Again glad to be one of “the eighteen “.

heavy - is your MC240 stock ? Mine is 1961 and super modified.... sweet amp for sure
And no amount of “ on “ is going to save ya from SMPS hash, so get those isolated from delicate analog devices and on the ugly side of your electrical panel. Both.
Unless they run a very high-biased Class A, I'd never turn them off but to change a power cord, etc. My gear is rarely turned off.

If tubes, then yes, turn on to use and then turn off when done due to heat and the lifespan of the tubes.
Most preamps ought to stay on 24/7. Mine have no power switch (solid state). Eve tubes, if they run moderatlely cool to warm are best just left one. There is some sonic benefit and the power drain/heat is minimal in many preamps.

Power amps are anther story. I’ll steer clear of tubes where the tube itself and state of bias is critical to how much it may be left on and if you can even get replacements!

For solid state power amps, it depends on the design. Without getting techie some have standby modes that allow them to warm up in a claimed 15-60 minutes. There is no danger to leaving them on - just heat, and wasted electricity -- which is both a cost and an enviro factor.

The real answer on how much warm up can be best determined by your ears. If you cannot hear the difference reliably between 30 and 120 minutes, then who cares? turn them off. Yes, as noted, there is a surge at turn on but all most stuff is 30 year old prototypes and has been turned on and off thousands of times. QED. For me, 30-60 minutes n the power amp (from **standby**) is sufficient. From truly off, several hours. That’s why i designed standby!

I have had owners and dealers claim a subtle improvement over days. Maybe its true, but it is also very much at the margin and likely only audible by those with excellent hearing, great systems and/or terrific imagination.

I really don’t believe that there is a single answer, given the many variables. And the difference between waking from standby and truly powering up, and stabilizing is just huge. In my case you can hear the image expand, the bass extend, and the top recede. Its very dramatic ( and kinda cool).


I turn both my SS Pre & Amp off. If that is what you decide to do then this is what I found out here. Laughing Our Faces Off. This refers to the Amp, L & O = Last ON
F & O = First Off
This made sense to me as my last system, Infinity Kappa 8's with an Adcom 555II amp. This set up for 15 years did the same thing every time when turning off in this way with the volume turned down all the way down. For 15 or so seconds the speakers had a popping noise, then I turned the Pre off. 
Exposure to continuous heat will reduce the life cycle of electronic components. There is little to no argument most folks turn off their tube gear after each listening session.

This same argument applies to SS devices as well. Resistors and capacitors will deteriorate when exposed heat over time. So after use, it is recommended you turn off your SS amps and pre-amps. There is an argument from some quarters that turning devices on & off reduce the life cycles of electronic devices. However, damage due to heat would be much worse. Modern SS amps/preamps warm up rather quickly as in 20-30 mins. So the wisdom of leaving SS amps/preamps 24/7 is highly questionable.
My two cents.
I asked service tech at Mark Levinson on my 532H and he recommended to leave on. 
Mine are all SS, i leave them on 24/7-the amp in stand by. If i leave over night  i unplug from wall.
heavy - is your MC240 stock ? Mine is 1961 and super modified.... sweet amp for sure.


All 5, MC225,2x240s,275, and a pair of 60s are all stock, I have all the parts for PS, upgrades and pio caps, and a pair of 24k cases for the 60s.
The one 240 though has EU caps in it, so they didn't self destruct, like a lot of the other bumblebees. It is VERY special, indeed.
 I did mod up a 275 GG, that I managed to blow up a while back, (cable drop), it's quite a bit better than stock. Still it's a KT88 unit.. Not my favorite valve. I'm a 6550, El34, 6L6,  guy these days.. :-)

Summer/Winter, wahoo, night and day where I live. 33-35 is considered cold here, and it is, if you get caught in it. But I've seen, 45 at night, and 105 in the day, two days apart. Tube gear is not real partial to a REAL cold starts. My Cary stuff can pop a fuse with a real cold start too.

My metronome C6 preamp (with tubes) is always on “stand-by” when I don’t play. The Wavac 805: after listening:”off”. To put on your equipment: first Source, than préamp, than Poweramp. For turning off: first poweramp,than preamp an at last: the source.
I have two systems and leave the PS Audio PowerPlants on for both. But I power off my tube integrated when not in use. I leave on my Pass Labs preamp. But everything else that is SS and can go on standby mode I put in standby mode. On my headphone station I power off all the gear that I can reasonably power off. Most of that is SS. One amp is a Schiit Moljnir and I power that off. 
Always off, unplugged from power.
 When I will listen, I will power on amps, pre and disc player 24 hours before I listen.
 All solid state gear.  
 Goes for both my systems, they sit dormant and unplugged until I want to have a listening couch sit down.  
I may go months without listening, and when storms roll in, they are already unplugged.  Vacations, when not in use, they are unplugged and not in use.

as mentioned,  if listening on a fri & sat night, I will power all on, and leave on for the whole day and afternoon starting on Thursday, to allow them to warm up.

  Amps on first and off last has never failed me!

  They always sound better after a good 24hrs+ of being powered on and sitting idle!
 Been doing this since I was a wee mite in 1985 with my first separates system!
always took care of my gear, as I payed for it w my own money!
You may do whatever you feel is right, and works for you.

You have to turn off tube amps but solid-state amps you can and SHOULD leave those on all the time!
I’ve never had a SS amp fail due due to on/off. Every device is unique. If you can hear a difference with yours and don’t mind paying for unused power, by all means keep them on 24/7. You better have real surge filter/suppression in series for the enivitable electrical storms.
Of course tubes have finite life spans. You gotta pay to play.
Check your stuff with a Klil A Watt.
Most "stand by" uses 90% of the kWh for a few seconds of faster play.
No audible difference with mine.
I even unplug the power sucking cable box off nightly via a timed outlet.
We all have our views and opinions, including technicians and engineers.  Depending on the design of the product on/off can play a role for one and a different role for another.  I have tube gear for phono stage and preamp, SS for power amp.  Everything is connected to a quality AC conditioner with surge protection.  I turn on about 30 minutes prior to listening and turn off when done.  Heat is the enemy of electronics and my preference is to minimize heat exposure to my electronics.  Tubes have a life span far less than SS gear so it's a no-brainer to turn off that gear after use.  For simplicity sake, the SS amp is turned off as well.
That said, even with the 30 minute warm up prior to listening, there is ALWAYS a period of running time in which SQ gets better.  I find that about 30 minutes in of listening and the imaging improves, bass gets tighter, and soundstage gets wider.  About 45 to 60 minutes and all improves still again.  Listening and enjoying the slow improvements is actually rather fun.  Personally, I prefer to do things this way rather than have heat prematurely deteriorate the electronics.  As stated, we all have our views and opinions; these are mine, yours may differ.