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Can temperature fluctuations affect audio gear?

Don't know about this...some owner's manuals say that you should allow equipment and tubes to warm to room temperature before using them, but this is different. My audio room is upstairs, isolated from the thermostat. Have to keep the door closed so the dogs don't venture in there and create havoc. Hence, in summer, the temperature in the room regularly goes to 85 degrees or so. In winter (like now), it will easily drop below 60 degrees. No need to worry about equilibration, since the gear is always in there, but should I worry about the temp fluctuations? Could get a baby gate to keep the dogs out, then it would stay 70-72, but otherwise, in winter a space heater is the only option.
afc
bigbucks5
184 posts
 
12-04-10: Magfan
Heat and temperature are 2 different things.
And NO, the amp won't always be the same temp delta from ambient. In SS, for example, you have a max temp possible....say the junction temp of the devices. In a hot room wont' the difference drop as the room temp approaches junction temp? Or will the junction keep getting hotter until failure? Isn't there an upper limit to the temp of an amp?
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That's the point. The junction temperature of SS electronics is a delta above the board temperature. As the ambient increases, the board temp and the junction temp increase proportionally until evntually you exceed the max allowable device temp and then failrue will result some time thereafter.
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almarg
9,670 posts
 
Magfan & Bigbucks, I'll say first that thermodynamics was definitely not one of the shining successes among the courses I took in college, but pending further info from Magfan's PhD friend I believe that Bigbucks is correct.
Magfan: In SS, for example, you have a max temp possible....say the junction temp of the devices. In a hot room wont' the difference drop as the room temp approaches junction temp? Or will the junction keep getting hotter until failure? Isn't there an upper limit to the temp of an amp?
The maximum rated junction temperature of a semiconductor device, less some derating (margin), is the maximum temperature that is safely allowable. It is by no means the maximum temperature that is "possible." And yes, it can keep getting hotter until its mtbf (mean time between failure) is severely degraded, or until immediate failure occurs.

Think of it this way: If everything has been turned off for a while, everything (including internal device junction temperatures) will be at the room ambient temperature. The energy that is fed into each device, less whatever amount of energy the device outputs to other devices, and less whatever amount of heat is conducted or radiated away from it, can only have the effect of heating the device up from that starting temperature.

Best regards,
-- Al
magfan
1,583 posts
 
Let's straighten out the question? OK?

The OP wanted to know if heat was OK, and if the huge seasonal temp fluctuation was OK....
Well, I think we all agree that heat in excess is bad for electronics. Cold, especially condensing cold is perhaps worse....ZAP.

Heat cycling can also damage gear. Can Expansion and contraction of solder connections work them loose? Some of the new solders are less malleable than in years past. Wasn't that one of the problems with the X-Box?

Do we agree that cold air is better at sinking heat from electronics? It would seem that as the ambient temperature and temperature of the electronics got closer and closer, the amount of HEAT transferred would get less and less. It maybe that BigBucks is right, but I don't see it. The constant delta above ambient may work but I just see stuff getting hotter faster than the room it's in....especially if the room is externally heated...sunlight, hot day...etc. At some point, the junction temp of an output device would be nearing limits and be unable to dump enough heat.....thru all forms of shedding...radiation, conduction, convection....(others?) But would that be at a constant delta from ambient?

The electronics would raise temperature as the amount of heat soaked away got less but that would catch up to you at some catastrophically high temp....which would be a much higher temp that you'd like your room!

No matter the physics equities here, I still think that a room of 85f is WAY too hot for good electronics. Maybe just sitting there....OK, but I'd never run my TV in that hot a space. Or even my 'd' amp.

After living in the same house for 20+ years, I installed AC before last summer. Glad I did, too.

And Al, I agree with you, too. Starting from 'cold' stuff starts shedding heat as stuff warms. Convection. Conduction. Radiation. All play a part in shedding heat. However, that heat goes somewhere. A bad / Extreme example is my RPTV. It kicks out a jumbo amount of heat. That lamp COOKS. Well, it sort of keeps the house thermostat artificially WARM. The TV is about 6' from the thermostat. The rest of the house cools and gets downright cold.... But that TV warmed thermostat says that all is well.

I don't mean to play the 'expert' card, but I will call my physics buddy. He is a hi-end semiconductor engineer and should be conversant with these issues. I'll ask and post back..Give me a couple days. If I have to buy him lunch, I'm billing you guys for 1/3 of the bill....each! just kidding.
paperw8
165 posts
 

some owner's manuals say that you should allow equipment and tubes to warm to room temperature before using them

i use solid state devices only so i am not familiar with such advice. the thought that comes to my mind is that the reason why the makers of tube equipment might offer this advice is so that you don't shatter the glass tubes. if you took a glass out of the freezer and immediately filled it with boiling water, it would likely shatter. when you power up a tube amplifier, i would imagine that the temperature would rise pretty quickly. so, if you left a tube amplifier out in the cold overnight, hauled it inside, immediately powered it up and started playing music at high volume, then i would imagine that the tubes would heat up pretty quickly; maybe while the glass tube housing is still cold. if the glass shatters, then your tube would be shot.

that would be my hypothesis with respect to tube electronics...
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