Threat of fire from audio equipment


Just read Art Dudley's new piece in Stereophile, and found myself becoming all sorts of worried. For many, many years now, I've left solid state equipment powered on -- except during thunderstorms or when heading away from home for extended periods. Now, I'm rethinking this practice.

See Mr. Dudley's article here:

https://www.stereophile.com/content/listening-193-nordost-flatline-cables

My questions:

Is what happened to him the rarest of things, like someone's being struck by lightning? Is putting an amp (or another piece) into standby mode any better than leaving it on -- when it comes to preventing fire, that is -- or can a unit in standby mode burst into flames just like one that's powered on fully? Do others worry about fire? As much as I appreciate a fully warmed-up system, if fire is a legitimate concern, I'll routinely switch things off when I'm not around and listening. Or about to listen.

I'd love to learn what others -- especially those who understand engineering and electricity -- do with their equipment.

Thanks very much.

Howard
 
hodu
I used to leave my tube preamp on all the time until one of the caps in the power supply went bad and caught on fire.  The fire was contained in the unit, but the smell hung around for a while (it was the reason we went down to see what was happening, so that was a good thing).  So I don't leave my electronics on 24/7 anymore.

If you read the article, you'll see why Dudley (properly in my view) didn't  name the maker of the amp.  Even the best of components in an amplifier can go bad.  Now if it was a design flaw, that might be a different matter.
Had that happen once, but it was the power company’s AC coming in to the house.

Left the stereo on, was outside, playing with and walking the dog....came back in and the power was cycling, on and off...at about the rate of just over 1 on/off cycles a second.

Right about at the correct rate to blow up a power amplifier, as best as possible.

In this case, the amplifier was of the kind with no protection circuitry of any kind, other than a fuse and power switch. The best sounding kind of added protections, which is: NONE. (’Best’ in audio quality means: Go big or stay home)

It also had three hundred thousand microfarads of capacitance in the power supply, at +/- 90VDC, or 0.3F (farad)/90VDC. This amp would run for 30 seconds after it was shut down. Full DC capacity, zero problems with being like a DC power supply, instead of being an amplifier for audio. (hitting the power switch will not save your speakers, foolish puny man!)

The amp had blown a main capacitor, but just...kept on going, zero in the way of failsafes (just the way I like it), but also blew a set of prototype speakers, where the drivers where no longer available, anywhere.

Not my best day, but far from the worst. It was just audio, not life nor..the records.

The AC continued to cycle like that for nearly an hour.

I still like my amplifiers to be that way. The gain in sound quality from the lack of the extra circuitry, relays, etc, is worth that much to me. I’d pay many thousands for it, like others do in various ways. In this case, I paid in damaged goods, in the given luck of the draw.

Art was burned by chance, and not much else. 

We don’t truly know that, the capacitor might have been run too close to it’s voltage spec, but in well designed gear, it’s unlikely to be a problem even there. (re fire)

Conservative design rules the roost in the west, as, in the west...we’ve learned all the fire lessons we ever want to see or deal with, over the past 100+ years of electricity in homes. We've built up a system of specifications in parts and design and use of parts.. so that the correct amount of overhead remains in any given part and design application. All our build and design professionals are trained in this way. (that would be a 'design technician/technologist'. We used to have these as actual degrees available in schooling... engineers don't get much on this all important point in electronics education/build)

China? eBay? Not so much. Very very not so much.

All that DIY stuff out of china is not done by the level of professionalism and knowledge that is required to make sure that things are safe, stable, and long lived and don’t start fires in your home. The parts inside don’t have enough quality and overhead built in, the kind that comes from quality base materials inside the given part itself, nor the designer and builder of the part having the background for it in lore learned.

20 years from now, it will be better, but right now, it is still the wild west in circuitry and parts, out there in eBay DIY cheapo land.

Few in the west, as casual buyers, have any chance to understand such, as they’ve been under the protective umbrella of professionalism in electronics --- for their entire lives. So they buy this eBay kinda stuff, with no idea whatsoever of what they’ve allowed into their homes. A literal Sht-ton of dangerous and bad design, build and part decisions, in quite a few of them. And if that stuff burns your house down, and the insurance company figures it out, you’re out of luck. That stuff generally has zero regulatory or inspection approvals of any kind.
Thanks for calling the article to our attention, Howard. Regarding your questions, IMO all that can be said is the not particularly helpful common sense notion that in general the risk is very small (perhaps less than the risk of driving a car), but it is not zero. And I would expect that leaving a component in standby mode reduces the risk greatly, compared to operating mode, but again not to zero.

Personally the only component I’ve ever owned that I left on 24/7 was a vintage Mark Levinson ML-1 preamplifier, from the late 1970s, which had no power switch, was designed to be used that way, and had a fully enclosed metal case without even any ventilation slots. And was not located near anything particularly flammable. Between me and the prior owner it ran essentially 24/7/365 for more than 30 years, before developing some functional (as opposed to safety-related) problems.

FWIW, with that exception my own policy has been to play it safe, and just allow time for my components to reach a stable operating temperature before doing any critical listening. That means no more than an hour with any component I have owned, and less than that in most cases.

Best regards,
-- Al
Well the question of whether to leave Amps on 24/7 has finally been answered.  
Over the many years I had my stores, I never had anything like this happen.  We left most equipment on 24/7 in all the stores and I still leave solid state gear on at home.

I did have a few pieces blow-up/catch on fire, but they were operator error situations, not the unit's fault.

Toasted quite a few drivers in my time also...