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Has Anyone Here Thought Of The Possible Fire Potential Of Tube Amplifiers?

NoTransistors

Dual Turntables Super-Restorer
My Scott amplifier [and those before it], Dual 'table, and Pioneer tuner have been living in a short 'n narrow shelving unit that had been left by the home's previous owner. He had a fax machine in it. Black Formica over flakecrap [I have been toying around with the idea of a glass/chrome shelving unit].

Turntable on top.
Tuner under amplifier in middle.
A few records and a multi-meter on bottom.
Unit had been to the left of the T.V. table and between the speakers, but in an effort to rearrange the room, and not make it the center of attention in a long and narrow living room, it has wound up across the room, next to the listening couch, and close to the curtains. The amplifier is in the open shelf unit, certainly not touching window curtains, but the fire-starting thing did come across my mind. The amplifier just got a softer [less dried-out] power cord from a Scott parts tuner, and when I opened the Scott to install this thing, I was amazed that where the wire is soldered to the lugs of the always-on accessory socket, the lugs were the thickness of paper away from the chassis. Guess what, this outlet is not fused. Hardly 21st Century UL. approved. I might re-open the thing and simply eliminate the connections to this point, even though the outlet has nothing more than the Dual connected to it.

So, has anyone ever had an actual issue with this stuff? I remember an owner of a Dynaco SCA80Q transistor amp almost lost his home to fire. The amp had caught on flire, and the guy, who I believe lives in Africa, has a thatched roof of all things. He was a member of either AK or A.A., [that other group]. I had the same Dynaco, and it had done the same thing [power supply distribution board]. That was a terrible amp.
 
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yeah some of the construction methods used are a little sketchy. Terminals are too close to the chassis, fuses weren't where they made sense to be or even there in some cases, those line to chassis caps that shorted out, you name it. Its an excellent idea to fix this stuff if you want to run it and not have to worry about it. I do.

Only thing I've actually seen fried was line to chassis caps in things. I've opened at least 2 units where the caps had exploded and had evidence of charring on the chassis. I do add fuses to things that don't have them. No good reason to not have a fuse in gear IMO.
 
I have lots of tiny UL smoke detectors. One needs to reside over the stereo.
And is there any reason for the chassis to be hot? The plug needs to be reversed about 1/2 of the times you put it in the socket.
 
I remember when chassis on just about everything were Hot!! Hot!! Hot!!
The toaster, the chassis and rabbit ears on the TV, my Cuban G.F., etc.
 
New XY safety caps, and other upgrades as they make sense. Use surge protectors as the power supply, and turn stuff off when you're not using it.
 
Got a huge norfolk pine and a 15' tall corn plant in our audio room, and a lot of other plants ...
and a lot of faith ... and a fire extinguisher handy!
 
Maintain a common sense approach to placement, and fire should be the least of your worries. I'd be more worried about how much crap I got plugged into the wall sockets behind the system, but how many folk add in a dedicated circuit or two for that?

(I did, and I sleep better for it)

Best tip I ever heard about tube equipment ... never turn your back on it ... leave it unattended, and you're just asking for trouble.
 
And is there any reason for the chassis to be hot? The plug needs to be reversed about 1/2 of the times you put it in the socket.

Not really, but its caused by the line to chassis capacitor. The easy fix for this is to fit a polarized cord, and put the cap on the neutral side. As long as your outlets are wired properly, the chassis won't be hot.

Its not really fully hot either, its a fairly low amount of current that can develop. Enough to give you a tingle, not enough to cause any harm.
 
UL & CE requirements (plus all the others) exist for good reason. If things aren't fused, I add them. Wood cases look cool, but IMO they're a bad idea if not covering a nice fireproof sheet metal enclosure. I've never (knock on wood) had a problem, but it still keeps me awake at night.
 
I still have my Dad's Bogen DB-212 amplifier. It used up tubes like water because of the A.C.-fed filaments. My father made a solid walnut case with an open back and a grill over the 6V6GT output tubes. There is also a sheet of asbestos lining the inside top of the enclosure. For the sake of memories, I need to rebuild that precious little amplifier.
 
AC on the filaments won't hurt it. Most amps run AC heaters. They started making tubes specifically to take that duty in the late '20s. I've actually still got some late 20's AC tubes in service that are working fine yet.
 
I've seen flames shooting out of a vintage amp before. IMO, The only way to "truly" be sure is to run modern, well constructed amps made of all modern, quality components. Any piece of vintage gear with vintage components should remain at least slightly suspect and should never be left running unattended for any significant period of time....
 
The only fire I have ever seen (from audio gear, at least..) was from a old crusty power cord on a record changer thing at the first Mid Hudson Valley GTG a few years ago.... held in A FIREHOUSE no less. Smoke everywhere, folks dashing to open the windows to clear the nasty smoke. Hilarity!

Echo the above - Even stuff I have tottaly rebuilt, added a fuse, polarized cord, all new parts and tested for 100's of hours, I do not leave stuff on if I am more than one room away.....
 
Tube gear gets plugged into a power strip that gets turned OFF when not in use. That strip also has a breaker in case any unfused gear gets plugged in, it can prevent a disaster. It's easy to be safe, but easier to be careless. Be careful.
 
The only fire I have ever seen (from audio gear, at least..) was from a old crusty power cord on a record changer thing at the first Mid Hudson Valley GTG a few years ago.... held in A FIREHOUSE no less. Smoke everywhere, folks dashing to open the windows to clear the nasty smoke. Hilarity!

haha, I was there. I remember that. Not a smoke detector in the joint either as I recall.


Then something kept me going back to Lafayette for more and more tubes.

entirely possible something else was wrong with it, or it just ran the hell out of the tubes but I doubt it was caused by the heater supply unless it was too much voltage for whatever reason.
 
I used to work for an electronics repair/recycling place, and let me tell ya, stuff from all generations can catch fire. I worked on mostly TVs, and I had three of them catch fire right in front of me, and several more that you could tell had been on fire before they came to me.

DISCLAIMER- I'm not that lousy of a tech to have stuff catch fire, lol. 2 of the TVs were models I knew to be fire prone, and we let them fail-to-fire "for educational purposes". The 3rd was a projection set that had a "FIRE HAZARD" sign taped to it when it came to us. It had no value, so we rolled it outside, plugged it in and let it burn. It was a fun place to work, hehe...
 
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