flyfisher

That reminds me of a favourite quotation: [i]If the human mind was simple enough to understand, we'd be too simple to understand it.[/i]

Will definitely have to watch it now!

Even that would have it's own ethical problems, e.g. risking the life of a patient by not using tried and tested drugs, but I was thinking about specific placebo trials, not an A/B comparison of two drugs. This is why medical trials and things like animal experiments have to be approved by ethics committees.

[i]"Every stereo ever made has an option to adjust the bass. There's no guitar knob. You won't find a way to make the drums louder. The singer's output is set and out of your control. But the bass...you can turn up the bass. Nobody turns it down.[/i]" Brilliant. Never mind the other 10 reasons, that one says it all!

One ancillary advantage of active speakers is that they're great to use outside at home in the summer. Just plug an iPod into a powered wedge or top and instant music without the need to set up mixers, amps etc.

I wonder if he created that baseline at full speed straight off or if he worked it out first and built up to speed with practice? I've tried playing it and it's too much for me, though I like to kid myself that I haven't persevered enough

One aspect of placebo research is the ethical implications. So, for example, it would be unlikely to be deemed ethical to conduct a clinical trial of a cancer drug versus a placebo because it would require the withdrawal of treatment from the placebo group. Fair enough, but I wonder if people would regard it as an ethical issue to run a trial that might prove to someone that, say, their choice of spending tens of thousands of pound on a Hifi system was a waste of money because they only 'thought' it sounded better, which might destroy the effect for them? Having said that, I recall reading somewhere that placebo effects can still be measured even when the person concerned knows they are in the placebo group, which seems very strange indeed. Edit: Found a link to that last point: http://www.scientificamerican.com/podcast/episode/placebos-work-even-when-you-know-10-12-23/

[quote name='Woodinblack' timestamp='1392568754' post='2370116'] If you do hear this, replace your pickups with ones that have been potted properly. The sound of your voice through a pickup is due to the vibration of the coil over the magnet because the pickup hasn't been sealed. This will happen on cheap pickups (and older ones where the potting has rotted out), but shouldn't happen on anything that costs over £5! [/quote] . . . Or perhaps the voice vibrating the strings? [quote name='Woodinblack' timestamp='1392568754' post='2370116'] Ah, that is different. you will be able to hear recorded sound as the pickup can detect the magnetic variations that power the speaker in a recorder. [/quote] That's similar to the way the TC Electronic toneprint thing works - using a smartphone to send toneprint data to their amps via an audio signal sent through the guitar pickup.

Horizon eh? cool as a cool thing that! I'll catch it on iplayer.

You know what, I'm out of this. I'm going to leave you both to your "sh1t happens" world.

[quote name='TimR' timestamp='1392479702' post='2369239'] I am sorry but when you make statements like those below, it leads me down a certain avenue of thinking. [/quote] [i]"RCDs are the thing to help prevent electrical shock, not fuses. And even RCDs can't offer total protection.[/i]" Please feel free to explain what is wrong with that statement, instead of making vague personal insinuations.

[quote name='TimR' timestamp='1392479702' post='2369239'] I am sorry but when you make statements like those below, it leads me down a certain avenue of thinking. [/quote] What, like these you mean? [quote name='Big_Stu' timestamp='1392395226' post='2368214'] Sh*t happens sometimes that can't be explained, get over it. [/quote] [quote name='TimR' timestamp='1392418542' post='2368687'] Sometimes as big Stu says 'sh*t happens'. [/quote]

Ha!

You're so wrong, which is the danger with making assumptions. Let's try to stick to some facts shall we, which is what questions try to elicit, and leave the personal stuff out it please?

[quote name='chrismuzz' timestamp='1392473960' post='2369160'] Actually it was the 102P mentioned in the OP. It would be interesting to see what the actual weight difference is. To be fair if its only 1.4kg that's hardly a deal breaker. [/quote] Sorry, I think I was confused about the references to a '210' cab, doh! But yes, some figures about the actual weight difference would seem to be the key issue here.

To be fair, Marco has stated that only one cab has increased in weight and not the one the OP mentioned. It would be very helpful if the OP could post the actual weights of the two cabs that started this whole topic. A set of bathroom scales would probably be accurate enough.

I've re-read this discussion and can't see where you mentioned anything about the threads of a bolt affecting things. You alluded to contact resistance but then so did I in my specific question about the volts drop across the bolt, which you avoided. Tauzero, in a single post, has clearly explained his suggestion in an easily understandable way that requires no second guessing about what he actually means. Perhaps that's because, like me, he's trying to understand things rather than just personalise them?

[quote name='tauzero' timestamp='1392424601' post='2368759'] At the risk of perpetuating this yet further, the other thing to consider is contact area. While a fuse has a big flat contact area to go into the big flat [1] fuseholder, the threaded bit of a bolt provides a series of teeny-tiny contact lines. That's going to be the major factor in considering the current-carrying area as a fuse has a considerably larger contact area than conductive cross-sectional area, while for a threaded bolt the reverse is true. [1] Well, curved, but an even surface [/quote] Now that's the most constructive post so far in terms of better understanding this whole thing. Interesting.

[attachment=155214:facepalm.jpg]

[quote name='Big_Stu' timestamp='1392420825' post='2368722'] [b]I[/b] always was - by merely relating an incident as it happened, with nothing added, [/quote] So if you related an incident about seeing a ghost, you'd get all indignant that someone might question it because they find it hard to believe? So what have we all learned from this discussion? 1. You've seen a bolt (of unknown metal) glowing red hot in a 13A plug fuse holder while connected to an electric fire 2. I find it hard to believe how that can happen 3. Discussions with TimR, the forum electrical expert, yield no conclusions about how the required amount of power to turn a small section of bolt (of unknown metal) could practically be dissipated within said bolt (of unknown metal) and cause it to be heated to a red hot temperature 4. You're upset because you think I've called you a liar 5. Both you and TimR think sh1t happens 6. I'm bemused by the whole thing and will try to curb my curiosity in future.

[quote name='TimR' timestamp='1392420317' post='2368713'] No. It's the constant questions when you get an answer you question that as well. It gets worse because the fuse at the DB would be a 30amp and probably capable of 40-50 amps for a couple of minutes. The bolt (if carbon steel) would have to have 10times the cross sectional area of the copper to have the same resistance. Then we also have to look at contact area and resistance of the bolt with the holder. As big Stu implies [b]unless you do a forensic examination of the whole thing it's all educated guesses.[/b] Fires do happen due to faulty electrical equipment that's protected correctly and tested and checked regularly but they happen more often to equipment that isn't. Check your gear regularly and don't cut corners because it's not expensive. It makes sense. [/quote] Yes, of course it's all educated guesses, which is why I was asking for yours to see if it made any more sense of things. But no matter. I'm just a little surprised at how relaxed you seem to be about electrical fires in 'properly protected' equipment. No wonder Sh1t happens.

[quote name='Big_Stu' timestamp='1392418825' post='2368690'] Where you stated that it was steel, without qualifying that it might be another metal as I did. Unless of course - as I said - you're talking about another hypothetical bolt in another plug, rather than the one that I brought up. The one that you - while admitting you're not an expert as TimR does genuinely appear to be - are having such a hard time believing did glow red hot without tripping the house fuse. [/quote] And where, exactly, [u]did[/u] I state it was steel? If you re-read the thread carefully I think you'll find it was TimR who first mentioned steel. Carbon steel actually. My first mention of steel was "[i]What sort of massive current do you estimate would be required to cause an M8 steel bolt to become red hot?[/i]", which reads very much like a question rather than a statement to me. [quote name='Big_Stu' timestamp='1392418825' post='2368690'] FWIW The house was a council owned, I know that much. It was long enough ago that it may have been one of the old fuse-wire boxes - in which case the guy maybe put something else in that too, instead of the proper fuse wire. [b]IMHO there are too many possible variables to be able to know why something didn't stop the bolt in the plug, whatever it was made of - from glowing red-hot.[/b] [/quote] Now you're talking some sense, and I entirely agree with you, which is why I was very care to write "[i]I also find it hard to believe that a metal bolt could be glowing red hot[b] while the consumer unit fuse had not blown [/b]or even the house wiring cabling to the socket had not burned through first.[/i]" I really think you're being a tad over-sensitve about all this and have jumped to conclusions. If I'd wanted to call you a liar I would have done so straight away without bothering to qualify my comments, but that would have been ridiculous and is why I didn't. I'm sorry if what I wrote upset you but I that wasn't my intention and I can't predict how someone might misinterpret something.

@TimR - Industrial datacomms equipment. Why are my questions strange? And even if you think they are, why not try answering them? The volts drop across the bolt for example? I'm asking it because your post estimated 6kW "through the bolt and fire system combined", which is fine, but I'm sure you understand that the amount of that power that is actually dissipated [i]within[/u] that bolt and therefore acting to heat it up, will be largely dependent on the voltage across that bolt. Which is why I asked the question. Is that really so strange?

[quote name='TimR' timestamp='1392417355' post='2368674'] Really you don't need to make sense of it. Today we replaced a fused spur at work that had caught fire with a 13amp fuse in it. That was due to a faulty electric thyristor on a heater. Everything else was in order. The fuse will only ever blow if enough current flows for long enough. [/quote] Doesn't that sound like a case for suggesting that the fittings involved are not adequately protected by the rated fuse? I know that a 13A fuse will not blow as soon as 14A flows through it, but so do the people that define all the wiring regs, so you'd think they'd take account of that sort of thing wouldn't they? [quote name='TimR' timestamp='1392417355' post='2368674'] A pat will open the plug and check the size and condition of the fuse and hopefully spot any charring or discolouration early. [/quote] 'Hopefully' sounds a bit vague for a H&S procedure to me!

Where did I say I 'knew' it was steel? I just suggested steel for the basis of the discussion with TimR just to make some rough approximations to see if some sense can be made of the whole thing.