Craig Sawyers

On the set of Skyfall. Having a laugh and a joke.

Just getting back online in NZ, so a truly belated one Steve!

A very very belated one Dan, new zealand time!

I did not realise that he was born in the same county as me - Co Durham in the North East of England. He was from here https://en.wikipedia.org/wiki/Horden He seems to have learnt a lot from HP Lovecraft's style, including tales about Cthulu. Still 86 is not too shabby an innings. RIP Brian Lumley

I have to fess up here. In the Falklands, Rapier missile emplacements were dropped on the beach head. Rapier missiles were tracked to their (aircraft) target at that stage using S-band microwaves. That neatly jammed the radar on our own ships - who promptly told the Rapier crews to turn off the missile tracker. That left them with the only option to sit in the launcher nest and manually track using a rate joystick and sighting crosshairs. Now they were not good at this, and led to a need to train crews in how to manually track. From the Wikipedia entry https://en.wikipedia.org/wiki/Rapier_(missile) "In the 1980s, a new training simulator system was constructed in Stevenage. This consisted of a 10-metre (33 ft) radius hemispherical dome whose inside surface was used as a movie screen onto which terrain images were projected. A copper vapor laser projected images of targets and the missiles in-flight on top of the background imagery, while a smaller helium-neon laser simulated the Rapier's tracking flare. A complete Rapier targeting unit was placed in the center of the dome, and its guidance signals were captured and sent to the simulator to update the position of the missile. The projected laser imagery was bright enough that it could be tracked by IR imagers and seekers, allowing it to be used with the updated Darkfire versions of the Rapier with their IR cameras, or other IR seeking missiles like the Stinger. This system was sold separately for use with other missile systems under the name British Aerospace Microdome. And laser image projection system was developed my me as a consultant when working for https://www.paconsulting.com/about/global-innovation-and-technology-centre . The whole British Aerospace simulator was darned impressive. There was a 1kW audio system in there to give a realistic sound effect of launching, as well as sound effects from the targets (helicopters, jets etc). Scared the bejeesus out of me when we were testing it.

There was an interview with some US administration hawk on the UK's radio 4 a day or two ago. He said that his advice was to hit Iran hard - really hard. And take massive economic sanctions against China, who he accused of supplying arms to Iran. God help the world if this crazy couplet of policies is put into practice. First off - how many countries does the US (and Europe for that matter) cheerfully arm to the teeth? We found that out during the Falklands War, where our ships were hit by Exocet missiles - previously supplied to Argentina by the French. And US/UK's reputation in attacking countries does not end well. Libya? post Ghadaffy it is still a shit show. Afghanistan? Similar - it took the ultra orthodox Taliban five minutes to take control once we "withdrew". Iraq? Still a mess, and only now just about recovering. And the crazy partition of Israel into Gaza and Israel by the UN in late 1947 was never going to end well, in the same way that the UK partitioned India (by Mountbatten) into India and Pakistan - again in 1947 - is still a matter of massive tensions in the region. We really do fuck up the globe big time.

Cross with a Newfie? 😁

It is a little after the fact but on Thursday last went to see The Enfield Haunting, a play in London with Catherine Tate and David Threlfall. Dramatization of a true story about a poltergeist in a semi detached house in Enfield (a suburb of London) in 1977 and 1978. Major media coverage at the time (newspapers and the BBC) and a ghost hunter (played by Threlfall) permanently in the house. Turned out to be the two daughters having a laugh that got out of hand. The fiction in the play was that this daughter nonsense raised a real poltergeist that was causing true mayhem.

RIP Melanie, far too early at 76. It must have been sudden because she had just signed a record deal.

Blimey that is going back a bit! No idea what the context for my comment was at this distance in time.

Have a really great one!

Happy birthday Grahame you expat! Have a spiffing time, old bean.

Ha ha! I was peering at that plate of food and wondering what on earth it was - until I googled it and found it was dog food!

Totally amazing fusion of progressive jazz electronics and trad instruments. Try and spot the time signatures.

Sorry to hear about that Brent. Condolences to you and your family. 20 minutes of CPR is really impressive - it is really exhausting even for 5 minutes (I'm first aid trained). It won't be any consolation, but CPR has only a 5% survival rate. If you are lucky enough to have a defibrillator handy, that increases to 10% survival. RIP Jack.

That looks truly awful Birgir - stay safe. Fingers crossed it does not get to the hot water feed.

Yes that is what I meant.

A hissing/rustling noise sounds like corona breakdown somewhere. Unlikely to be physical damage during shipment, but not impossible. Justin should be able to help more specifically than me. Your unit seems to have the super-expensive super-dooper Alps RK50 pot BTW. Very nice.

When you see movies of someone as a young person you forget they grow old and die. RIP Ryan. On a similar topic, was watching Die Hard last night, filmed when Bruce Willis was in his early/mid 30's. Born a year before me in 1955, he is now down the dementia road at 68. In his last movies a couple of years ago, he would turn up and wonder why he was at a movie set, and had to repeat his lines coming through an earpiece having lost the ability to learn them.

Yes. It it based on a spreadsheet implementation of a model in a National Semi databook. But with more frequency data points, and with amplifier noise taken into account. And yes, you can always parallel opamps, summing their outputs via 10 ohm resistors. But even a single NE5534A is less than 2.5dB worse than the SNR with a noiseless amp (which is -80.4dB - depending on cartridge R and L) - so it is diminishing return. Parallel two NE5534A and you get to 1.6dB - so all you have found is 0.7dB in SNR. Parallel 4 and you find another 0.4dB and hence get to around 1dB of a noiseless amp.

Woah - how did I miss this? Belated happy birthday Todd!

A bit of good news - the OPA210 (single) and OPA2210 (dual) have a lower voltage noise, crucially the same current noise, as the NE5534A. They also has lower 1/f corners and stupidly low distortion. Introduced in 2018 it looks like it will be around for a good long time. The critical number is - how does an RIAA stage with an opamp with vn and in compare with a noiseless amp? With an NE5534A - 2.32dB noisier than no amp at all With an OPA210 - 1.61dB noisier than no amp at all Both numbers with a realistic MM cartridge load of 610 ohms and 0.47H Both amps are very close to the maximum possible SNR with a noiseless amp - but the OPA210 is even closer than the NE5534A. SOIC (or smaller) only and about 2.5 times the price of the now defunct NE5534A - but it looks like it does the job very nicely.

Suffers from the same problem as the OPA1611 - similar high current noise (4 times higher than the NE5534A). Predicted SNR is 75.3dB - so identical to the OPA1611.

Indeed. The combination of noise voltage and current was ideally matched to the resistance/inductance characteristics of a moving magnet cartridge. And lots of commercial designs used the NE5534. I have a spreadsheet that calculates S/N ratio with RIAA. AT 5mV the NE5534A returns 77.9dB with a typical MM cartridge of 610 ohms and 0.47H. The nearest equivalent IC is the much more recent OPA1611/12. Lower voltage noise but critically higher current noise. That gives 75.3dB, so 2.6dB worse s/n. My spreadsheet does not take account of 1/f noise. The OPA1611 has much better performance here than the NE5534A, so some of the 2.6dB will be eroded by that effect and it will make the comparison a closer run thing. Discrete opamps can give lower noise for RIAA EQ, and indeed Sam Groner developed a discrete version of the NE5534A that was better performance all round https://groupdiy.com/threads/just-for-fun-discrete-ne5534.57544/ . No surprise that the low noise dual he specified in 2004 is obsolete though.

Heads up - the best (ie best noise performance) single opamp for moving magnet cartridges - the NE5534 in all variants has been obsoleted by both TI and ONsemi. So if you need some for stock before this excellent device is obsolete sand, now is the time to buy. I've just ordered 50, which is enough to see me out.