starting equiment that ic cold from being shipped

Is it a real thing that you court problems if you turn on an ice cold amplifier or pre-amp without waiting 24 hours for temperature to rise.  I have long awaited Krell FPB and KCT shipping tomorrow,  It's single digits in the Midwet.  Should I wait a full 24 hours for the equipment to warm inside before introducing any electricity into the components?


Don’t know if this will be usable info being that my experience has involved MUCH less expensive amps and temps that were generally in the high 20s at their coldest (coastal TX) but I’ve run a 100 w/ch receiver for 10 yrs plus out in a metal shed in all weather extremes common to my area with nary a hiccup.  FWIW…

That's a good point but both Krell and other google responses made me doubt the safety of turning on ice cold equipment.  Condensation could take out boards say some google posts.  It's amazing how cold it stayed the last time.  After 12 hours the amplifier still felt like a block of ice in my living room.

I have always allowed my equipment to warm up before using it.

Unless your home is a swamp, I can't see how condensation would be an issue. Most homes in the cold air of winter have low humidity.


Yes, they do but when a cold object meets warm air moisture forms.  Just look at windows.

Yes, let it come to room temperature with low humidity. May want to pop the top to make sure any condensation evaporates with great airflow. Good luck. 😉 

“I have always found that a blowtorch can expedite the process..”

I think @bossa will be up for it if you wanna send your amp over 😂

I would have a real hard time waiting 24 hours. But I definitely can see the value in waiting until it reaches room temp. I would wait until it feels to the touch like it has reached room temp. All the cooling fins should work both ways.

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I received my Pass mono-blocks on a day when it was -15F. They had been riding around in the back of a truck all day. I took them out of their crates to inspect them and frost immediately formed on the aluminum faceplates. The humidity in my home is < 50%.

They were at room temperature and dry the next morning when I plugged them in.



I would open them up and let them acclimate for 3+ days (mainly because of moisture).



I too am in the upper Midwest and just yesterday received new electronics from Hattor. They were on the truck 3 extra days due to the snow slowing delivery. They were cold when I unpacked them so I let them reach room temperature over 5-6 hours - no condensation (I checked inside) and no problems.  Of course waiting longer will not hurt.

Tubes yes you should wait a bit so everything warms up some so the temperature change isn’t as drastic.

SS, probably won’t make any difference.

All the best.

If it were me? 24 hours. Keeping equipment wrapped would make evaporation take longer and increases risk 

Some water is going to condense inside the amp as it warms up

Water + amplifier = bad

Need time to everything to come to ambient temperature and for condensation to fully evaporate

It sucks, but better to wait than to fry the amp on your first turn-on

We have had a number of loudspeaker customers complain that the speakers don't work in extreme cold because the ferrofluid freezes.  Yes, this is a problem that can rip your drivers apart if you take a speaker that's been sitting at -30C and try to instantly get loud sound out of it.  When they are outdoor speakers, we recommend a small conditioning signal of low wattage, nothing that will make the coils move, for a few minutes, just to warm up the innards and get the fluid back to being fluid.  It may take a short while to get the sound up to normal, but these are the things we have to do with climate change.

I imagine the same holds true for the electronic components.  Nothing works as it should when it is as cold as a stone.  Give it some time to come to room temperature to avoid the possibility of damaging components.

I was told specifically by the Krell repair manager to NEVER blow a hair dryer into the amp, so that won't be happening. 

This logic is what made me think keeping it wrapped will prevent condensation from happening quickly. 

From Quora:


This isn't so much about warming up. This is to prevent condensation from forming inside the device. I wear glasses and when the temperatures outside are close to 0°C or below, and I walk into a crowded bar, condensation forms instantly on the glass. When the air outside is cold and dry, and you bring your equipment into a room where the air is warm and humid, condensation will very likely form. It's best to keep the device sealed and let it sit for a minimum of 2-3 hours. Some recommend as much as 24 hours. This way you can ensure that as the device gradually warms up to room temperature, condensation does not form, and even if it does it gives it time to evaporate.

I would open them up and let them acclimate for 3+ days (mainly because of moisture).

My frost knee jerk at the title was just give em hell.

But then thought about moisture. So I agree with with @dekay (and the others to wait)

But if it is sparks off the sock static low humidity then it shouldn’t matter.


"My frost knee jerk..."  I guess auto correct is warning me to wait!   Krell advised waiting but had to be asked.  There was no proactive warning but after reading other sources, I decided that there is a chance of problems and since shipping costs me around 500 round trip, I will wait.  Most things i have read suggest that leaving the items wrapped is a good thing as it hinders condensation from forming inside box and plastic wrapping and acclimates slowly.  I will wait at least 24 hours and continue to play my toy stereo from Goodwill.


Just stick 'em in the oven at 100 deg F for a couple hours; will markedly reduce any latent humidity and make your cat happier when you set it up for a listen and they take up residence thereon.

The obvious seems to have passed you by. Ask your dealer. Get anything they say in writing, then you can follow this advice and use it as evidence if you need support / make a warranty claim.

Opening them up to warm up is a terrible idea. This will expose the electronics to any water vapor in the room and greatly greatly increase the likelihood of condensation forming. Leaving them sealed more or less restricts the opportunity for condensation to any water vapor present at the time of shipment from the factory - condensation that would have already formed as the unit cooled during shipment.  However, I am guessing the manufacture likely packs the equipment with desiccant that absorbs all water vapor present at packing and prevents condensation. However, the desiccant won’t work quickly enough to prevent condensation from an entire room full of water vapor. Keep it sealed and be patient for 24 hours.

FYI - my day job is Chemical Engineer. 


@dekay ​​@holmz  - I feel bad. I meant no disrespect when I said opening them was a “terrible idea”.  It was an in-artful way to open my response and I don’t want to promote discord on this site.

I do stand by my opinion that it will be better to leave the box sealed to warm up. 


I have personally been in the same situation, frigid amp, and went one more step

and put it a garbage bag and sealed it and YES waited four days which is when it felt like room temp.

barts hates moisture and electronics agree...




Unless my heat-seeking moisture missile is doing the talkin'...




By the way modern double pane insulated windows should prevent moisture from condensing on the interior pane because the argon gas in between the panes of glass stop the cold air from hitting the interior pane. Thus no condensation. Old school single pane windows would without exception have moisture on them from condensation in the cold months. This happens even with low humidity rooms. So, to be safe I would wait on plugging in and playing any audio equipment that could potentially cause condensation. 

@barts @feldmen4 @dekay Ok, i have anywhere from 24 hours from the chemical engineer, to four days from barts.  I really don't think I need to wait longer than 24 hours but I would like to hear the logic for such a long period of waiting.  I thought i was showing restraint to wait 24 hours and keep box sealed.  :)  I'm not sure I can stand it to wait that long unless you have a strong argument for why it would take that long for amp to come to room temp or any condensation to dissipate.  Thanks to all who are giving me advice and opinions.

@bobpyle  No, the obvious didn't escape but I haven't spoken to the dealer in years and won't.  I spoke with Krell because the amp/pre-amp is long out of warranty, I paid and it's my issue.

3 days open/unwrapped just as a safety belt.

The unknown is how much moisture is trapped inside the sealed package, thus my suggestion to open it up to air for such a long period of time.

Maybe open for 24 hours, then placed in drier room that gets less heat (for as long as you can stand:)?

I just measured our wall oven and neither of your Krell's would fit.



I would open them up and put the components upside down if you are worried about condensation. If it does form and drip it will be at the top of the components where there are no electronics. I would leave them that way for 24 hours to be safe. Once they get acclimated to the room you can set them up and put in standby. This will slowly warm things up. After a few hours turn it on and leave it on for 24 hours to finish charging up the caps. After all that you should be good. Some of these components can take 200-500 hours. So you will definitely be drying it out. I hope this helps. 

Some funny responses. I once blew up an older TV with a picture tube turning it on when I had just taken it out of my garage in winter. It arced, smoked & made some horrible noises in its dying moment. Picture didn’t actually implode which might have been worth the whole thing - it was a old piece of junk. 

Now I know better & if I something is cold, I remove from it’s box or boxes & let it sit at room temp for at least 3-4 hours which should do it. Like others mentioned,  Condensation is the cause. 

There is no such thing as a “sealed” amp. At best, a top panel might have a bit of foam to damp it a tad from vibration. Otherwise, any moisture will be present. It certainly isn’t necessary to open anything up, and I highly doubt the conversion of moisture would result in a dripping amp. But as mentioned, it’s just a smart thing to do to wait. This is assuming the amp was below say 40° or so. Much warmer and it is doubtful it would be an issue. Sub freezing? Without doubt let it warm up for a couple of hours. No worries.

@feldmen4 Thanks for the gentlemanly apology Matt, but I took no (zero) offence.
And your expertise in the field is seeming more helpful than not..



"My frost knee jerk..." I guess auto correct is warning me to wait

I was thinking condensation, so it is either auto-correct…
Maybe I pictured it being so cold that the condensation frosted up like a very cold drink?

If it was an auto-correct, then it must be the latest release of the auto-correct s/w, as it got it exactly right.

@bossa Early in my career I did thermal analysis - modeling problems just like this. I can tell you that it depends on the thermal properties of the materials the amp is made of. More or less the denser the longer it will take to come to equilibrium (room temperature). My 24 hour comment was flippant and was just reflecting your initial post. OMG that’s an awesome pair of components- just looked them up. The FPB is massive - and as you say “ long awaited”.  I would suggest 3-4 days but that is purely a conservative SWAG (scientific wild ass guess). I think this situation calls for being conservative - what is 4 more days after all the time you’ve waited just to get it right?

Regarding open box or not. All air contains water vapor. How much water vapor is in interior air depends on ambient conditions (outdoor temperature and humidity) unless the air is conditioned or humidified. For where @bossa lives humidifying air is common in the winter which would provide more available water vapor in the interior air. Even if they don’t humidify there will be much more water vapor in the air in the room than in the box. That means much more H2O that could wind up as condensation on the various cold surfaces of your components than is in the box. I have never received even a cheap electronic component that isn’t factory packed in a plastic bag with some sort of desiccant packed inside the plastic bag. That plastic bag + desiccant will keep your component nice and dry as long as the bag is sealed. Once you open it the desiccant cannot work quickly enough to protect your components and condensation will likely form.  As I mentioned in my first post if water vapor inside the box was an issue the condensation would have already formed during shipping as your components cooled. I guarantee you do not want to open the box during the warm up period. 

@agentwja - what you experience with double pain windows does not mean the water vapor in the house has been reduced. Rather that water vapor can no longer reach the cold inside surface of the glass windows here it would condense (just like on the cold surfaces of @bossa components). The cold inside surface is only exposed to a sealed area that is filled typically with argon gas to reduce re-radiation but it is also dry so there is no moisture ( water vapor) to condense on that surface (the inside surface of the outer pane of glass). The inside surface of the second pain which is exposed to the water vapor in the room is not cold enough for condensation to form - rather it is close to room temperature because of the excellent engineering of these windows. 

Regarding the cooling fins - yes they will work in reverse during the warm up but would only be effective if the amp is out of the box. However the fins would also increase air movement around the amp and thereby increase the likelihood of condensation. 

@feldmen4   Wow, thanks so much for this detailed analysis.  My balloon just popped however.  I've been awake for hours thinking that today is the day!  I have kept both boxes sealed as I completely agree that keeping things wrapped will hinder condensation.  I must tell you that the amp has been shipped to Krell 7 times between 2015 and 2021 for repair/recappping/etc.  It has been an audio nightmare, but I so love the combo of the KCT and the FPB 300CX that  I have refused to wave the white flag.  I'm pretty sure they don't pack it back with desiccant after repair.
Waiting 3-4 days seems like torture after so many absences.  I will say that Krell suggested 24 hours.  I spoke to a dealer in Milwaukee (Ultrafidelis) and I spoke to PS Audio who makes DAC and amps.  The tech said he got what i was saying but hadn't seen it as an issue in their business.  I will say that the Krell has many more parts than their offering.  The dealer said if your amp feels as cold as a bottled beer from the fridge, he would wait.  Any warmer than that and he said I could turn it on.  My plan is to do it in stages...first standby for hours and then on but not playing music for more hours.  Thanks so much for your input and expertise.

My logic is very simple as I'm a simple guy!

My point is to take it out of the box and put it in a garbage bag to prevent airflow and then put it in the warmest part of your house.

Many moons ago while in the military I was an Avionics tech working on jets.
So I have seen first hand where an airplane flies high and the aft equipment bay becomes very cold.  We were stationed in North Carolina a humid place. After  cycles of this some corrosion can set in causing electronic issues.

Your amp is not an airplane and won't be subject to freezing/thawing cycles.

Apparently you love this piece, so I would take all preventative steps.
This is just my two cents, but it is what I do.  Enjoy the piece, I hope it doesn't require any further trips to Krell.




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The cold inside surface is only exposed to a sealed area that is filled typically with argon gas to reduce re-radiation but it is also dry so there is no moisture ( water vapor) to condense on that surface (the inside surface of the outer pane of glass).

Technically it is more like convection or maybe conduction?

One can imagine the old video game Pong, and the pong balls carry the heat from one side to the other like a pack mule.
The argon pong balls are slow and carry heat from one side to the other in each bounce.
The helium pong balls move faster so we get more bounces per minute.
So if each load of heat the heat on the mule is the same, we simply get more loads carried over time with helium pong balls than with the argon ones.


The fellows talking about garbage bags amd not opening the box, sort of doesn’t make sense to me, as I am used to seeing the devices wrapped in a bag inside of the box with a little bag of magic desiccant crystals.
If it is one of those similar deals here, then just keep that bag sealed.

The box and Styrofoam shipping protection, only insulates it to delay the warming.

I have started my engine and it is good to be back in high fidelity. Thank you all for your input. I fed the units power in standby after about 30 hours of getting warmer. I concluded that while still cold, the amp was warmer than the cold bottle of beer I was to use as yardstick for safety. It remained in standby for several hours and then I turned everything on but muted with no music for a couple more hours. I am now playing music and boy it just keeps getting better, as these warm up. I expect them to be cooking in another three hours or so. I feel fortunate to live in a time when we can bring such great sounds and great musicians into our living rooms. For the vast majority of history, people had no access to such pleasures.