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Amplifier porn
That is using magnets in attraction to apply a force to unipivot suspension string, presumably to resist the tendency to wobble. Attraction between magnets is of course stable.
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Amplifier porn
Simple opposing magnets are not stable. The only thing that is stopping this instability is the jewelled bearings - but because of the magnetic instability there is more force on the jewelled bearings to apply a centering force that might be naïvely be expected. I guess that is why the Castagna model A was pretty much the only tone arm to use the magnetic principle. Although at around the same era there was a design and prototype for a parallel tracking arm the used opposing magnets in a saddle arrangement; but that never made it to production. Now it is now possible to levitate stably. The idea being the the repelling magnets are stabilised actively using a set of coils. Around 8cm diameter (so not small) and because of the active control a potential source of electrical interference near to the cartridge. Then there is Meissner effect levitation. That is not entirely daft with high temperature superconductors. Of course it needs the superconductor to be cold enough, so a source of liquid nitrogen is needed. I've done exactly that as a table top experiment when my kids were small, and I was working at Oxford Instruments, so had ready access to chunks HTc superconductor, and a small expanded polystyrene pot for the LN2.
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The Knuckledragger 3rd Memorial Slow Forum Post
Each of his three marriages has been to a model. The mind boggles.
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Happy Birthday Stretch!
Happy birthday Andrew, O tall one! Hope it is an awesome one
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The Knuckledragger 3rd Memorial Slow Forum Post
That absolutely made my day!
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Woodworkers of Head Case unite!
That is a hell of good story Steve - I'm massively jealous! We saw Emmy Lou in concert around 6 months ago in Birmingham Symphony Hall (UK). She's 79, and made it clear that was the last time she'd tour outside the US - because of her age she finds it difficult now on endless long hauls. She was superb - lost the clear as a bell high notes, but still absolutely awesome. Back in the late 70's and getting seriously into audio, standard albums that showed off the quality (or not!) of a system was Linda Ronstadt albums. And one of my favourite albums even now is Trio - Dolly Parton, Linda Ronstadt and Emmy Lou Harris - released in 1987 (nearly 40 years ago - eek). Like you said the quality of the harmony and the way their voices complemented each other raises goosebumps. They actually spent well over a decade after the TV show you remember, Steve, trying to follow up with an album. But their personal tour commitments got in the way until Trio was finally recorded.
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And now what did you do TODAY?
Carole suffered more angst than me when our kids went to college; Rob to Warwick and Liz to Essex. But the thing to remember when this happens is "Job done". You bring these little creatures into the world totally helpless, they progressively grow up - then they are adults, and quite rightly fly the nest. Now at 41 (Rob) and 37 (Liz) they both keep in touch regularly, and with each other. By phone and WhatsApp. Rob lives in the NE of England, and Liz is on the Gold Coast in Australia with a permanent residence Visa (so she can apply for citizenship). WhatsApp is a wonderful tool.
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And now what did you do TODAY?
We did three nice things in London yesterday. Theatre, matinee at the Old Vic. "How the other half loves", a farce by Alan Ayckebourn with a stellar cast including Roger Allam. Absolutely laugh out loud hilarious https://www.oldvictheatre.com/stage/other-half/ Followed by an Indian meal at the famous Cinnamon Club https://cinnamonclub.com/about-us/. Canapes, starters, main course and pudding, two glasses of wine and coffees UK£115 for two. Stunning value for money in London; had to pre-book of course because it fills quickly. If any of you all get to London and like really subtle Indian fine dining - go there. Followed by this https://luminiscence.com/london/ at Westminster Cathedral (Catholic). Narrated (recorded) by Hugh Bonneville and sung live by the renowned Cathedral choir. The cathedral, built in the late 1800's to early 1900's is huge, seating 2000 .
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The Knuckledragger 3rd Memorial Slow Forum Post
Curiously, the Romans actually mainly spoke Greek. But who can forget "He's not the Messiah, he a very naughty boy!" And:
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RIP someone or another
Although I never saw Dolly Parton in concert, we were lucky enough to see Emmy Lou Harris earlier this year in Birmingham Symphony Hall (UK). At 79, she'd lost her highest notes, but she was absolutely awesome. After a couple of mumbly numbers she said to the sound mixer at the stage side "Can you please rebalance the sound, and bring my voice up" That did the trick!
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RIP someone or another
Well that is a shock for sure. RIP the legend Dolly Parton.
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SJY Argos Electrostatic Headphones
There was a guy on another thread who recently bought some cable from China, and randomly found that a magnet stuck to it. It was iron wire with a thin copper coat. And what a stoopid idea of them using braided cable, and ridiculously short. High capacitance (usually around 50 to 100pF/m, or even more) and very low inductance (sub uH/m). Oh and use the hardback version of Art of Electronics 1.5m would add at least 75 - 150pF!!!
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The Knuckledragger 3rd Memorial Slow Forum Post
This is a not so funny incident locally around 10-15 years ago, where an elderly lady put the car in reverse instead of forward, and pushed the pedal. Shot back and pinned someone by the legs against a brick wall. Life changing injuries.
- AnTek transformers are made in China.
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The ultimate DIY? A Stax SRM-T2!
That, good sir, is a thing of beauty!