Craig Sawyers

Totally beyond credibility. Experiment: I wired up a Fluke 8060A on ohms range with a Fluke 87V on micro-amps range. I could not get a reading on the 87V try as I might. The 8060A indicated a resistance in the mega-ohm range (1 to 10M), even pushing the tips into painful pointy contact with my fingers. I then took a 9V battery, and wired it via the 87V to my tongue (the traditional old fogey way of testing a 9V battery by feeling the tingle. Welcome to my world.). The tongue is about as wet and electrically conductive as it gets. I measure 12uA from a 9V battery on the tip of my tongue with the connections separated by a few millimetres. To get anything approaching the ten *milliamps* needed to give you heart problems would need you to stick a nail through the palm of each hand. I was not prepared to take the first steps in self crucifixion to test that out. But I could not get within three orders of magnitude of a problem current of that even on my tongue. So let's move on to the *real* problem of keeping you all breathing when dealing with dangerous voltages like 500V or 1000V - where the potential gradient across the skin can punch through and set up a real kick-ass current flow from a grunty power supply like the kgsshv one.

Yeesh. Sounds a bit like a carbon dioxide TEA (Transverly Excited Atmospheric pressure) laser that I built back in the 70's. Machined all the bits myself, and it was a real lethal set up. The capacitor bank was two metal plates with screw clamps holding hockey puck HT ceramic capacitors. Around 10nF total at 20kV. 2 Joules storage and completely lethal - just out on the bench. Early 20's then and immortal, you realise. Found out about dielectric recovery the hard way. Discharged the bank, unscrewed it and put it on the bench. Ten minutes later, picked it up (in one hand, luckily) and it had partially recharged itself. Got a hell of a belt. After that I left a shorting link in place when it was not in use to prevent a recurrence.

For sure. The stored energy in a car battery is huge, and its current capability huge - easily 400 to 1000A without breaking sweat when you start your car, each day, every day. The stored energy in a 60Ah battery is 60 x 3600 x 12 = 2.6MJ - about three hand grenade's worth. Hence my flippant comment on vapourising your head. But that does not mean that they are dangerous from an electrical shock point of view under normal circumstances. The skin-skin resistance is typically in the tens to hundreds of k-ohms, so currents from a 12V source are tiny and no problem. The internal resistance of the human body however is around 500 ohms (ie not counting the skin). So if you pierced the skin deeply on opposite hands with electrodes to get direct electrical access to the internal wet stuff, and connected them on a car battery you could in principle drive 24mA through your heart, which is enough to give you a really serious problem. You'd have to try pretty damned hard though, and have real determination to do this. And you'd deserve what you got. There are many and various ways to kill yourself with a car, but electrocution with the battery is not high on the list of causes of vehicular mortality. But a DMM? With <1mA output current? No way. A much surer way to exit this mortal coil is to lose track of where your hands are when working on an big and ugly electrostatic headphone amp. Or the internals of an old generation tubed Tektronix scope, or the inside of a tubed power amp for speakers....

Agreed. If it were possibly to kill yourself with a 9V battery, there would be hazard warnings all over such batteries and they would come with shrouded terminals. Imagine the lethality of a 12V car battery! That would drive enough current through you to vapourise your head instantly

Indeed - the combination of high DC voltage (around 1000V from + to - rails) and high current (many tens of mA) is quite lethal if between one hand and the opposite, or one hand to the opposite foot when the current runs across the chest. Across a single hand, say from palm to finger, it is bloody uncomfortable and gives quite a fright (experience of years of fiddling with tubed gear). So for anyone that is new to dealing with this sort of thing PLEASE read up (as suggested above) about the techniques of building and testing such gear safely, or at least non-lethally. And don't work on it when tired - that is when most dangerous errors happen.

Check.

I just use regular dried yeast in my Panasonic. Works fine (provided the yeast is not too old; I had an old pack I tried to use up first off before buying new stuff). I can't make the extra large loaf size because it rises so much it hits the inside of the lid, so now only make the large size setting. I now get through a pack of yeast every two weeks - so now there is no expiry problem.

Ha! You too, eh? Sort of think you only do once - the resulting stunted warty high density loaf was a true thing to behold.

Deep enough to be a visual irritation. The damned domestic plant watering can had been put on the shelf (um - not by me) with the metal sprinkler rose sticking out. It was that that got me. Suppose I ought to be thankful that I was wearing specs - would sure have made a mess of my corneas.

These to replace the ones you stood on? I put a scratch clear across my new pair yesterday, so I'm royally pissed off.

I certainly had a deep memory that it was something to do with Magnepan. A google search for "magnepan vs apogee patent" turns up quite a bit of stuff that supports that, this being typical from newaudiosociety.com: "I believe there was an issue with a lawsuit from Jim Winey over at Magnepan....it seems he had a patent on the planar design and the Apogee version was a little too close to the patented version. Also, the head designer at Apogee croaked-it, which didn't help. What gets me is why Magnepan didn't incorporate some of the Apogee methodology into their designs. The Apogee's seem to be better integrated in the lows and highs, and I think that's partly due to the dual purpose midrange/tweeter, partly due to a better XO design and partly due to a much more rigid mechanical construction."

Well, I've worn specs since I was four, which is a cool half century ago now. Eyes went through some changes from 45 to 50 and have settled down again. Use the latest ultralight (read: ultraexpensive) varifocals, which are superb.

Maybe they are Pass at that. The big problem with the Apogees in general was the exceptionally low impedance. The original Scintilla in the early 80's was 0.5 ohm and low efficiency, and Krell got established when trying to develop an amp that would drive that sucker. Sounded bewilderingly wonderful - as fast as an electrostatic, but with real low frequency grunt and loud (if fed with enough current!).

Those are inspired by Siegfried Linkwitz's Pluto speakers Linkwitz Lab - Loudspeaker Design

Those are Apogee's fed by a Krell set up. Classic in its day. Apogee got killed by Magneplanar (or Magnepan as the company is known) going for their throat as infringers of their planar magnetic driver patent.

Flew back from three days (business) in Finland. It's colder in the UK than it is in Helsinki. At the moment.

Awesome!

Digitally remastered, final director's cut of Blade Runner. One of my all time favourite films/movies. Ridley Scott actually comes from my neck of the woods - Seaton Carew on the North East coast of England. I saw him once explaining that the opening scene of Blade Runner with fire belching out of the tops of buildings owed itself to his childhood walking to school in the dark past the ICI chemical plant, with gouts of flame bursting out as excess gas was burnt off. The perpetual drenching rail is also true to fact for that area of the UK.

You've got to feel kind of sorry for Guido Fawkes - after they caught him (in 1606) he was tortured so badly that he could barely sign his name to his confession. He managed to foil the drawing and quartering part of the execution (along with having his "private parts" cut off and burnt in a brazier before his eyes) by timing a jump from the scaffold and breaking his neck. Much to my surprise though, hanging, drawing and quartering was only removed from the British statute books in 1870.

Is that Uncle Pass with the quest to use up the planet's supply of FETs?

YouTube "VH1 Anti Rockstar". This is my daughter's latest best beloved Eric. He's a stand-up comedian, does adverts (of which this is one), and voiceovers. Since she's an actor-in-training all this works on a number of levels. Mind you, the end of this particular advert is exceptionally disturbing - be warned.

Well having just sprung for the 007 Omega2, and had all the softening up necessary domestically for a pair of headphones that are more expensive than any loudspeaker I've bought, I need to play the long game for the next 6 months or so to get an even more outrageous pair - I reckon a full thousand UK pounds on top of the 007 price. Or maybe I need to make a trip to Japan for some business excuse, and sneak them back in through customs.....shhhh. Mind you the 007's sound glorious driven by a Blue Hawaii. I can hardly wait....

I'm just catching up with the new and shiney thread - but I thought Omega was used for the last letter in the Greek alphabet - in other words the last word in headphones. Until the C32....

Now that was fuuuu funny

Wrong list - but.... Glad I'm not alone. I cleared the attic of hoarded boxes last year. Scary stuff. My Dad seemed to collect bottles (he used to home brew beer and wine). When he died I cleared out the cellar with my Mum and found well over 200 empty bottles. I did however find that my Dad had got from somewhere a box of thousands of tiny silver parts (14lbs of them!), which I have just sold (bullion prices are peaking) and bought a pair of Stax SR007 with lots of change left over. Thanks Dad!