tubelab.com said:
If you've got 5 tube amps, and have only built 1 class D, you might want to try some of the others, and different variations of them, you might find one that you like. In the class D forum there are a number of bottleheads that like them. You might post and ask their opinion of an amp that might appeal to you.
Tom.
Christer said:
I guess the ideal in my case would be a class A amp for the winter and a class D amp for the summer.
In case it wasn't clear, I meant this as a joke. I doubt anyone, well very few at least, would swap amps depending on season.
On the other hand, I don't feel inclined to build/buy a class A power amp, considering the horrendous prices of electricity nowadays. Maybe with speakers so efficient that a ten or twenty Watt amp would be enough.
IIRC barium and strontium are useful for their magnetic properties as wellMiles Prower said:
I don't think I'd miss mercury, though I have considered rigging my 83 for it's looks alone. As it turns out though, mercury begs the bigger question of street lighting. It just wouldn't be the same if they were all sodiums.
Theres a case for saying that Low energy bulbs are bad for you. The strobing they produce can have negative impacts on your brain wave cycles. This can be especially significant with children. Have you ever noticed how angry children get having watched TV for a few hours - this is the same effect.
I have about half and half Low energy bulbs to halogen and incandescent. I use the low energy bulbs in living areas which aren't permenantly occupied.
Shoog
I have about half and half Low energy bulbs to halogen and incandescent. I use the low energy bulbs in living areas which aren't permenantly occupied.
Shoog
The case against mercury vapor rectifiers
Let me be serious for a moment about a serious topic: mercury and mercury vapor rectifiers in particular. (Actually I really do take seriously all of this thread's environmental discussions, despite my warped sense of "humor".)
My worry regarding audio is this: what would you do if you broke a mercury vapor rectifier in your home or workshop? Some of these rectifiers have a sizeable pool of mercury inside. Can you guarantee that you will never break one? Couldn’t you drop one on the floor while building and testing an amp project? What would you do with the thousands upon thousands of mercury beads that have scattered all over? Would you try to scoop them up? You can’t even see them all. Would you vacuum them up, possibly spraying micro-droplets and vapor around the room? Would you first run for a carbon respirator? Would you immediately shut off the central air-conditioning/heating to prevent vapor circulation? Open the window? Would you first wash your clothes in case mercury spilled on them? Would you alert the wife and kids to leave the house? What would you do? It only takes one accident with a fat load of mercury in a mercury vapor rectifier to suddenly render a room and possibly a house into a toxic site. The risk of breakage may be very low, but the consequences are potentially severe. True, elemental mercury is not as toxic as methyl mercury (such as in fish). However, your body will make the conversion of some the elemental mercury vapor into methyl mercury, unfortunately. You wouldn’t have any symptoms for a while, and maybe never at all, but why risk it? I don’t know about you, but I need every brain cell I’ve got. Not even audio is worth it IMO. Would you be comfortable knowing that year and after year, those hidden beads of mercury are slowly vaporizing, maintaining a chronic level of mercury vapor in the air? Not me.
Mercury rectifiers look great, but I won’t have them in my house. If I receive a piece of vintage radio or test equipment for parts salvaging, as I often do, and if it has mercury rectifiers (or PCBs in caps or transformers, but that’s another story…), I will carefully remove those parts OUTDOORS and gently wrap them so they won’t break and then I discard them. I should take them to a toxic processing facility, but I don’t know where to go yet. As an aside, a buddy recently rebuilt a vintage 10,000 watt radio transmitter (and you think we audiophiles are nuts?) which had a large bank of mercury rectifiers behind a glass window. He replaced them with solid state equivalents (no, not with 1N4007s), partly out of concern about breakage and toxicity.
I could go on and on about the health issues that my wife, a physician, has seen with mercury toxicity in patients, a specialty area of hers. Studies have shown neurological damage due to exposure to mere parts per billion of Hg. Having gone to great pains (literally) and expense to have all the mercury carefully removed from our mouths, and trying to live a generally healthy toxin-free lifestyle, I don’t have any desire to bring mercury risk into my household.
Other sources of mercury – besides fish – are those old style thermostats with glass vial tilt relays filled with mercury, and old style mercury thermometers. Get rid of them. There are dirt-cheap digital alternatives to both which perform better anyway. Many years ago, in another house, I was shaking down a mercury thermometer for my sick wife in our bedroom. I whipped it too hard and it flew out of my hand and shattered on the wall. Thousands (maybe millions) of tiny mercury beads flew everywhere and became lodged in the carpet and even in the bed. Fortunately the mercury reservoir in a thermometer is much smaller than in a mercury vapor rectifier. This was before we knew much about mercury other than that it is generally-accepted as some kind of a toxin. We cleaned up as best we could, and eventually replaced the carpet.
Fluorescent bulbs contain some mercury vapor for the purpose of creating the UV light that makes the phosphors on the glass glow. I have none in my home, although we do have many at our clinic and I alone replace them with extreme caution. I also share the concerns mentioned by Shoog about the flickering light of fluorescent bulbs.
Anyway, enough blathering on about Hg. Many of you will think I’m an alarmist and I won’t change your view, but I had to say something here.
Let me be serious for a moment about a serious topic: mercury and mercury vapor rectifiers in particular. (Actually I really do take seriously all of this thread's environmental discussions, despite my warped sense of "humor".)
My worry regarding audio is this: what would you do if you broke a mercury vapor rectifier in your home or workshop? Some of these rectifiers have a sizeable pool of mercury inside. Can you guarantee that you will never break one? Couldn’t you drop one on the floor while building and testing an amp project? What would you do with the thousands upon thousands of mercury beads that have scattered all over? Would you try to scoop them up? You can’t even see them all. Would you vacuum them up, possibly spraying micro-droplets and vapor around the room? Would you first run for a carbon respirator? Would you immediately shut off the central air-conditioning/heating to prevent vapor circulation? Open the window? Would you first wash your clothes in case mercury spilled on them? Would you alert the wife and kids to leave the house? What would you do? It only takes one accident with a fat load of mercury in a mercury vapor rectifier to suddenly render a room and possibly a house into a toxic site. The risk of breakage may be very low, but the consequences are potentially severe. True, elemental mercury is not as toxic as methyl mercury (such as in fish). However, your body will make the conversion of some the elemental mercury vapor into methyl mercury, unfortunately. You wouldn’t have any symptoms for a while, and maybe never at all, but why risk it? I don’t know about you, but I need every brain cell I’ve got. Not even audio is worth it IMO. Would you be comfortable knowing that year and after year, those hidden beads of mercury are slowly vaporizing, maintaining a chronic level of mercury vapor in the air? Not me.
Mercury rectifiers look great, but I won’t have them in my house. If I receive a piece of vintage radio or test equipment for parts salvaging, as I often do, and if it has mercury rectifiers (or PCBs in caps or transformers, but that’s another story…), I will carefully remove those parts OUTDOORS and gently wrap them so they won’t break and then I discard them. I should take them to a toxic processing facility, but I don’t know where to go yet. As an aside, a buddy recently rebuilt a vintage 10,000 watt radio transmitter (and you think we audiophiles are nuts?) which had a large bank of mercury rectifiers behind a glass window. He replaced them with solid state equivalents (no, not with 1N4007s), partly out of concern about breakage and toxicity.
I could go on and on about the health issues that my wife, a physician, has seen with mercury toxicity in patients, a specialty area of hers. Studies have shown neurological damage due to exposure to mere parts per billion of Hg. Having gone to great pains (literally) and expense to have all the mercury carefully removed from our mouths, and trying to live a generally healthy toxin-free lifestyle, I don’t have any desire to bring mercury risk into my household.
Other sources of mercury – besides fish – are those old style thermostats with glass vial tilt relays filled with mercury, and old style mercury thermometers. Get rid of them. There are dirt-cheap digital alternatives to both which perform better anyway. Many years ago, in another house, I was shaking down a mercury thermometer for my sick wife in our bedroom. I whipped it too hard and it flew out of my hand and shattered on the wall. Thousands (maybe millions) of tiny mercury beads flew everywhere and became lodged in the carpet and even in the bed. Fortunately the mercury reservoir in a thermometer is much smaller than in a mercury vapor rectifier. This was before we knew much about mercury other than that it is generally-accepted as some kind of a toxin. We cleaned up as best we could, and eventually replaced the carpet.
Fluorescent bulbs contain some mercury vapor for the purpose of creating the UV light that makes the phosphors on the glass glow. I have none in my home, although we do have many at our clinic and I alone replace them with extreme caution. I also share the concerns mentioned by Shoog about the flickering light of fluorescent bulbs.
Anyway, enough blathering on about Hg. Many of you will think I’m an alarmist and I won’t change your view, but I had to say something here.
There are many dangers,...
but there are also many paths to take.
the EU regulation states 200K units; also, only TV's, battery chargers; many single items that consume more power (per device) than the average. Efficency comes at a price, which is always negotiable.
The average size community heat system has a limit of approximately 30 km's; this is due to engineering efficency; you must have more than 80% of your households subscribed to attain this efficency.
Lead and mercury poisioning are, historically, the worst physiological price we have paid as a race. Second only to heart disease and/or excessive fat consumption.
It is interesting to note that environmental theorist's give a variance in time to the eventual dissolution of the human race; from 50 to 3000 years, based on how soon we get over our over-bearing pride and come to a permanent psychological grip on our suicidal environmental tendencies.
I don't MEAN to be mean, but I am a career environmental health graduate, with experience in industry for over twenty years.
Sorry if I'm a bummer!!!
but there are also many paths to take.
the EU regulation states 200K units; also, only TV's, battery chargers; many single items that consume more power (per device) than the average. Efficency comes at a price, which is always negotiable.
The average size community heat system has a limit of approximately 30 km's; this is due to engineering efficency; you must have more than 80% of your households subscribed to attain this efficency.
Lead and mercury poisioning are, historically, the worst physiological price we have paid as a race. Second only to heart disease and/or excessive fat consumption.
It is interesting to note that environmental theorist's give a variance in time to the eventual dissolution of the human race; from 50 to 3000 years, based on how soon we get over our over-bearing pride and come to a permanent psychological grip on our suicidal environmental tendencies.
I don't MEAN to be mean, but I am a career environmental health graduate, with experience in industry for over twenty years.
Sorry if I'm a bummer!!!
I will someday, but they just don't look or sound the same. I know that they have improved a lot since the one that I built.
They will never hear my tube amp with the subwoofer pounding out the Rap music across the street.
Maybe I'm one of the few but my 845SE doesn't get used during the summer. The room gets too hot. I have toyed with the idea of building an 833A SE, but it would require external ducting similar to a clothes dryer vent! That amp would just be for show anyway.
If you figure out the energy dissipated as heat, it is not too outrageous for a reasonable sized amp. A 10 WPC SE class A amp will dissipate 100 to 150 watts as heat. How many hours a day do you use it? Then think about how many hours your wife left the bathroom light on. Or (in my case) the Amp could run for an entire day on the energy used by the electric clothes dryer in about 30 minutes!
There was an incident at Florida Atlantic University about 5 years ago where someone did that. They had some Mercury in a dorm room, it was spilled, and then "vacuumed". The Hazmat team was called, and the entire floor of the dorm was closed for almost a month!
We used to get the stuff by smashing old thermometers and light switches, then rub it on pennies, and pass them as dimes in the elementary school cafeteria. (Early 1960's) Now that I know better, I have no Mercury rectifiers in the house. The 3B28 can directly replace an 866 without Mercury. Works as good, but no blue glow.
Speaking of mercury, and this is not a joke. Here in Sweden we actually have dogs that are trained to find mercury. They did a large scale scan of, I think, all schools, particularly the universities, to try locating any traces of mercury that might still be around. Probably they concentrated on scanning labs and other rooms where mercury could possibly have been used. It could mean finding an old, forgotten bottle of mercury on a shelf, but primarliy they were interested in mercury that had been thrown in the sink and that was still stuck in the plumbing below. Maybe this is something you have in many other countries too, I don't know, but it quite fascinating that a dog can be trained to smell small traces of mercury.
Regarding fluoroscent tubes, is there any way to replace the mercury in them with something else? It seems the same technology has been used there forever without any improvement in this respect. I don't have many tubes at home, and could probably replace most of them with light bulbs, but I can't replace the daylight tubes I use when painting. Also, don't these low energy lamps also contain mercury? It is the same technique, isn't it?
Regarding fluoroscent tubes, is there any way to replace the mercury in them with something else? It seems the same technology has been used there forever without any improvement in this respect. I don't have many tubes at home, and could probably replace most of them with light bulbs, but I can't replace the daylight tubes I use when painting. Also, don't these low energy lamps also contain mercury? It is the same technique, isn't it?
Some people think that the future of nearly all lighting will be LEDs. They’ve certainly gotten brighter and more efficient. As I understand it, the white LED is really a UV LED, the UV then exciting phosphors that glow in a cool white. So, the principle is similar to the fluorescent bulb, only that a semiconductor device is making the UV rather than mercury vapor. Maybe that’s your answer.
Brian Beck said:
Thanks Brian, I had no idea white LEDs worked that way. It certainly seems then it should be possible to use three or more different phospors to get the desired colour temperature and Ra value, just as for fluoroscent tubes. We just have to wait until they are as bright and cheap, but of course, we won't have to replace them now and then, which saves a few bucks.
Another hazard warning:Since the thread seems to have broadened a bit from the original topic, now talkning also about healt hazards, let me remind you of Beryllium, which has been up for discussion before. A common type of insulator for RF semiconductors is Beryllium oxide. I have no own experience of them, but they are said to easily break and then release a very fine and highly toxic dust into the air. Such insulators are nowadays banned in the whole EU AFAIK, but still som RF transistors seem to have an integrated such insulator in the package (maybe that one doesn't break so easily). However, I think these insulators are still available and not uncommon in many other parts of the worl (ie. USA and Canada). Also remember that old equipment may have such insulators which may pose a serious health hazard when servicing them or just taking them apart.
Locally, while directly converting electricity to heat is much more expensive, using the electricity to run a heat exchanger is now cheaper per thermal unit than burning gas. It does take a few years to amortize the higher costs of the heat exchanger, but is easily worth it in new installations.
Beryllium oxide insulators are no joke. I know a non smoking man in his forties who has to carry oxygen due to it and other lung hazards. Especially with parts whose smoke has escaped, they will readily crumble to lung destroying powder.
Performance wise they are unique and hard to beat, being an electrical insulator having higher thermal conductivity than aluminum.
Performance wise they are unique and hard to beat, being an electrical insulator having higher thermal conductivity than aluminum.
phn, if you read my post again, I was in support of your statement. If I offended you, I apologise you for that.
People like Greenpeace, although I respect them for their effort to protect the environment of Antarctica from miners of precious metals and fossil fuel, they sometimes don't even know what they are talking about...
For example, a team of scientists found a way of turning not readily decomposing trashes at beaches into soluble and decomposable form, by firing small Mg bearings at them which ionises them.
Mg readily decomposes and their ions aren't that harmful. When the scientists were carrying this out at a beach, Greenpeace came to stop them and won't even pay attention to what the scientists are doing to help solving environmental problems. They argued that anything unnatural (firing Mg bearings) should not be done.
I wonder whether firing small magnesium bearings really does more harm to the environment than letting the trashes to sit there for the next five centuries...
James
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