Heat is one of the biggest enemies of electronic equipment. Does anyone know if this Heat is only at the output transistors and their heatsinks o8is it also present in other components within the unit.
I was planning to remove the top cover and with a IR thermometer going to check temps..
It depends entirely on how well the amplifier is ventilated. Heat also will work its way from the heatsinks through the chassis so over time the entire amp will get warmer.
If it’s designed well, it should live a long heathy life. Depending on the power supply sizing, load, etc.. they can get quite warm too. As do some resistors.
keep the dust off parts and the vents unobstructed, should be all you need to do.
I have a preamp that gets real toasty when the tubes are on. Most of the heat is from The power supply and rectification. Tube side of the chassis is cooler actually. I looked up the specs for the transformer to see what the operating temperature range was. While the unit gets very warm, it’s nowhere near the limit specified for the transformers max temperature range.
Heat in some of the older class-a designs radiates throughout the entire chassis, thus impacting all parts inside.
The old class-a solid state theory of leaving the amps "on all the time", comes at a price. Had to scrap some great amps "for parts" where certain boards and pieces inside could not be fixed or rare parts inside were not available any longer. Argh.
Some of my current mono tube amplifiers run much cooler than former designs, and thankful to designers for re-thinking how to make things last longer too.
I have Class A amps from Pass Labs rated for 200 watts; they're big, they're bad-ass and they're happening! All jokes aside, I don't concern myself with that (meaning heat), because it is what it is. First and foremost, I bought these puppies for their sound, and they make my Von Schweikert VR-6 floor standers sing like nothing else. Ehh, what I'm driving at is just take the good with the bad, because everything in life has some sort of compromise. For me, it must make my speakers sing, and sing they do so that makes me content. Anyways, I wish you happy trails on your OCD hunt for heat off your amps... Hah!
Life of electrolytic caps shortens by 2 for each 10degC increase, starting likely from 50 years. Other than cap replacement from time to time, you should not worry - electronics should last. I have espresso machine constantly on for the last 10 years. It is very hot to touch and has electronics inside (microcontroller). It is still working and I expect at least another 10 years from it
IR imaging and other direct temperature measuring techniques are used to detect hot spots in equipment and power distribution systems. Opening the equipment to see whatever it is you are looking for is wasting your time unless you know what you are doing and looking for. Enjoy the music instead.
I have a JC5 that I keep inside a cabinet. When I first got it, it ran really hot. I think there was not enough space around the unit to circulate any air. Then I bought one of these and put it on top, and it really helps. It's also very quiet. Great company to deal with.
Heat is a real problem. It takes a long time to fully warm up and sound good.
Does it help to wave your thermal runaway gun at things? Have you tried voice coils? What is the hottest chip inside your DAC? Have you tried a cooling fan? How hot does the motor on the cooling fan get? Did you buy the thermal gun thingy just for this? Or did you already have it for some useful purpose?
I had a Threshold 4000 amp(ClassA) for nearly 40 y...recapped once, never a single problem....only recapped as a precaution....Nelson Pass claims capacitor life much longer than many say....currently using Pass Labs X250.8...it does improve as it warms up, so I routinely turn it on about 30 m before listening....the amp runs warm to touch,NOT HOT, and of course the temp equilibrates throughout the unit....it is designed for that heat, and I have no doubt its life span will equal my prior Pass design.....
I do like that cooling device and at only 25db you can't hear that at all.
Hi Millercarbon
I have seen many of your posts and they are always well thought out. Not sure about your comment about IR thermometers but they have lots of uses in both automotive and many electrical purposes. A good one will only cost about $100 and lots of useful purposes.
Heat as the only enemy to electronics is not as simple as people say. Yes heat is one of the contributing factors to the demise of electronics but the actual failure comes from the heating and cooling cycle. Any good engineer will only use products with a heat rating that will work for the application. We all know the basic facts the heat will cause expansion and cooling will cause contraction. It is this cycle that will cause small cracks snd fractures in components. This is where the argument comes in to turn on and leave on as this eliminates the heating cooking cycle and will allow a component to run for a long time.
Ugh here we go....Sugden has been making Class A amps since 1967! Some of those amps are still going strong today with little to NO service! Go take a gander at the heat sinks on say, an A21 integrated.....massive!
Unless the amp is designed badly, the heat in class A SS amps is usually confined to the output stage. And almost all components will be fine except the electrolytic caps. The challenge is to keep the caps as cool as possible.
As noted above, the primary source of heat in class A SS amps are the output transistors. That's why they're mounted on the heat sinks. However, if they are used properly and have adequate temperature control, they're probably not going to be the first things requiring maintenance.
Capacitors, in particular the ones in the power supply, will age the most rapidly. While their eventual failure could prove catastrophic, long before then they will suffer from lost capacitance and increased ESR, which means less power available and more noise. This is why Nelson Pass, whose primary interest is sound quality, gives different advice than a person that is just looking to get the most use for their initial outlay.
Volume level was mentioned somewhere in above post. With a class A amp, this has no bearing. The amp is running flat out in spite of the volume level, even at idle.
All electrolytics die in time. It is just a matter of when. Some have longer service life than others, and are rated thusly.
I would think that sound quality and service life could go together in a design, especially at the asking price of the component.
Class A amps are designed to run hot so as long as the unit is vented properly you have nothing to worry about: I had a Threshold Stasis Class A/AB circa 1988 that was biased to run Class A most of time so it got very hot and I never had an issue until I got tired of it & sold it in in 2010: The designers like Nelson Pass know this and his companies Threshold & Pass Labs have buiding hot running & long lasting amps for years.If you are worried about heat, you should not be considering Class A amps or you can leave it off when not in use and turn on 2 hours before use.
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