I finished a session and was away from the studio for a week just went back down today and found that I left my focusrite Isa one on. Phantom power was on to my AKG 414. Anybody think that's dangerous?
WSS

I routinely left my old MOTU on for literally weeks at a time, sometimes months. It lasted for years. Right up until the day it died at the ripe old age of 7.
 
Fearing I'd shortened its life by turning it off so infrequently, I now make a point of powering down its replacement when I shut down at night. Probably for nothing, though. In reality, turning it on probably stresses it more than leaving it on (ever notice how light bulbs fail just as you turn them on?).
 
Assuming it wasn't crazy hot that week, any piece of solid-state electronic gear that can't handle being on for a week is garbage, and Focusrite stuff ain't garbage.

No, I don't think it is dangerous.

I once calculated that leaving my gear on all the time might cost me 100 USD per year.

So I turn everything of to save money.

I don't think it will hurt it, unless it was overheated.  If it was overheated and actually caused some type of problem usually those don't show up until later.  I have an ISA One and I've left it on for two days, by mistake, one time and it didn't (apparently) hurt it. 
 
 

Thank you gentlemen. BTW I do use a pair of Roland DS 90 powered monitors and I leave them on all the time. For many many years without a problem but I do power down the computer.
I do try to remember to turn off the isa one.
I appreciate the input.
WSS the

I don't think it is good to leave a mic out and powered on.  Just because it will collect dust quickly and increase the possibility of failure in the future.  They really should be stored away in their case after use.  

rumleymusic
I don't think it is good to leave a mic out and powered on.  Just because it will collect dust quickly and increase the possibility of failure in the future.  They really should be stored away in their case after use.  

Yep

I agree with storing mics for safe keeping.
 
Except for monitors, I leave all my gear on 24/7/365. Like bitflipper was saying, I tend to think the initial current rush is part of the cause of electronic failures but also the heat/cool cycles. I think the insulation (like shellac) on transformers and chokes and the various capacitor materials tend to age quicker with heating and cooling (expansion and contraction)
 
I may spend more on electricity in the long run but I think I save time by not having to recover from as many failures. Either way, "The world may never know."

DrLumen
I agree with storing mics for safe keeping.
 
Except for monitors, I leave all my gear on 24/7/365. Like bitflipper was saying, I tend to think the initial current rush is part of the cause of electronic failures but also the heat/cool cycles. I think the insulation (like shellac) on transformers and chokes and the various capacitor materials tend to age quicker with heating and cooling (expansion and contraction)
 
I may spend more on electricity in the long run but I think I save time by not having to recover from as many failures. Either way, "The world may never know."

An electronic tech told me a while back that it's best to leave gear powered up all the time, for these exact reasons. Makes sense to me. 
 
Part of "aging tests" routinely done by major manufacturers is to repeatedly heat-cycle the products in question. 
 
As for saving electricity, I'm all for that, but most modern studio units like interfaces and even PCs don't consume that much power, esp. when idle. If you're curious, buy or borrow a meter like the Kill a Watt.
 
Cheers,
Eddie

+ 1 to the KIll a watt meter and others like it. My Daughter was living off the grid for a few years and bought one so they could see what was hogging power.
Our studio's use very little power. 
I'll ask her if she still has it and run it on mine. 
I also have an old freezer someone gave me that never shuts off much,,, I want to test that pig.. might be worth it to buy a new more efficient model.