Craig Sawyers

There is definitely something wierd about watching topics. Nothing I can do gets the SRM-T2 thread on my "My Content" list, in spite of the topic having a watched status. And nothing I can do gets rid of topics I no longer wish to watch - their status is unwatched, but they still appear. Is it just me being dumb?

You have to be careful that your balanced power transformer has enough rating. The T2 amp takes around 120W, plus the power regulator dissipation, plus transformer losses - so at least 200W all up. What is the rating of your balanced transformer?

Will do. I think the thing that bewilders me particularly is the power of the ASA. They investigate every case, even made by a single individual (as with the two cases regarding Russ's mains cables). And once they have made up their mind using the ASA Council, there is absolutely nothing can be done. Major, billions turn over companies like Tesco and RyanAir just roll over. I even tried to find if anyone had taken out a legal case against an ASA ruling. As far as I found, the answer is no. So the ASA is all-powerful. In a court of law, you see your accuser. With the Government you can demand the information using the Freedom of Information Act. But with the ASA you have no such rights. Unfortunately this case has very dangerous implications for the Audio industry as a whole, for both products made and sold in the UK, but also for imported products promoted using literature supplied from the manufacturer. So it can and will hit any audio product imported into the UK from (for example) the US. It leaves it open to every frivolous claim that a product is advertised using wording that the ASA believes is either Untruthful or is Unsubstantiated by their own definitions. For example, Quad's famous "For the closest approach to the original sound" would be disallowed for the above reasons, and would have to be reworded "Quad believes that our products provide a close appromation to the original sound".

I dislike the thermasil stuff for bolt-mounted hardware - particularly with the heatsinks with an oval hole - always cuts through. I now always use either good old fashioned mica, or the 2mm thick ceramic washers that Kevin found for the T2 project. Thermal resistance of all three is about the same. The only time that thermasil works really well is when a spring clip is used to fix the transistor down, and there isn't a hole in either the washer or the heatsink.

A belated Happy Birthday! Hope you had a great one.

Ah - I have to declare an interest here. I have both been working with Russ on his three year battle with the ASA, and also he markets one of my designs under license (The Superkord-SD range), where the S is for Sawyers). The problem is there is a lot of hyperbole about mains cables, one way or the other. But this particular tussle had its genesis with a guy called Ben Goldacre. He has a column in a UK daily newspaper called The Guardian called Bad Science. He's also published a book of the same name (which I have read and enjoyed), and has a website with a forum. Ben Goldacre is a practicing medical doctor, and makes an excellent contribution to debunking the Pharmaceuticals industry, homeopathy, and the media portrayal of health risks. However, he has neither the training or techical skill to pronounce on other topics. However, around four or five years ago, and (as above) based on no technical evidence whatever, attacked Russ in national media regarding claims about the attributes of his mains cables. A few months later, he phoned the sales people at Russ Andrews and bought one - after which it went kind of quiet, which could certainly be interpreted as Goldacre actually having heard a difference. The next thing that happened was a *single* complainant, who is listed as being a customer of Russ Andrews, raised three objections (All public domain - check the ASA's site). A response was made by Russ before I got involved, the ASA appointed their own expert - a Nottingham University academic, and in 2008 the complaints were upheld. Subsequently a second complaint was made, not dissimilar to the first. At this point I have to say that the ASA protects the anonymity of complainants - you have no right in law to get this information. The Freedom of Information Act does not apply to the ASA, since it is not a Government body. This puts the accused under significant pressure - for example if the complainant is a media figure, which might allegedly influence the ruling of the ASA decision - well tough luck, defendent. You also have no right to know whether the first and the second complainant are the same person (it is highly likely that they are). Russ then commissioned Ben Duncan to carry out a programme of work to demonstrate the RFI rejecting properties of the woven cables. I was asked to scrutinise Duncan's work to make sure that there were no technical flaws (I sought and received no pay for this; it was simply a cause worth the fight). Ben measured the attenuation of the Classic, Reference and Signature power cables as compared with a regular IEC cable and a reference RG58 cable from 100MHz to 1.8GHz using an HP spectrum analyzer). What came out was that there was a baseline attenuation and a comb-like filtering effect, both of wich improved as the number of cables in the weave increased. Technically this is a result of the very low characteristic impedance of the woven cables - in the range 11 to 30 ohms - and impedance mismatch at either end of the cable produces the attenuation effect. It is significantly higher attenuation as compared with a regular IEC cable. These measurements were performed in Differential Mode only, at this stage. The ASA appointed a second expert, this time in the field of EMC. He objected to Duncan's report on the basis that (i) DM rfi is not the main problem, CM (common mode) rfi is the dominant source of interference and (i) the 50-ohm environment is not representative of a real mains supply; he suggested using an ISN at 150 ohms (which is no more representative than 50 ohms). We subsequently measured CM RFI attenuation, and showed that this was also significant and had similar characteristics to DM. Eventually, after 15 months, the ASA upheld the secnd set of complaints. They cited the lack of CM measurements (which is clearly incorrect) and other major incorrect and inconsistent assertions that were all covered in the techical reports and measurements. Because of the failure of process and content, the ASA have (most unusually) granted an appeal post ruling, which is under preparation. The average time that the ASA takes to rule is 13 days after complaint. The Russ Andrews case is now in its third year. The ASA council, who eventually rule on cases, is predominantly humanities based (including Andrew Motion, the Poet Laureate), and ill equipped to rule on a highly technical case. Now two things are worth noting. First is that Russ Andrews is a micro-business. It employs less than ten staff. They work out of a unit in Kendal in the Enlish Lake District, which is an employment black spot. It is neither wealthy nor has significant financial reserves. In my experience, the staff are committed and highly professional. Russ has a 60 day no quibble returns policy - and currently returns of mains cable products are running at 3%. So there is actually zero customer risk - you don't hear a difference - send it back for a 100% refund. They have also had to take out bank loans to fund their activities againt the ASA. So there the matter rests. Candidly, and given the history of this case, going back to Goldacre's media attack, I suspect that the ASA will still uphold their decision. And at that point, there is nothing more to be done - a small, sub-million-pound turnover microbusiness with 8 employees will have lost. History aside - do these products work? Well, my system is wired with a selection of Russ's mains cable and signal cable products, and both systems (including the T2) are sitting on RA's torlyle racks. Which is all the evidence that I need.

Check. All working now. The only setting I have not found yet is how to get PM's copied to my e-mail address. That was a kind of useful feature, and must exist somewhere - anyone cracked that one yet?

That is a 547 with 1A4 if I'm not mistaken. Hybrid with quite a good mix of sand and tubes. 50MHz bandwidth. Heh. I'm a bit of a Tektronix and test equipment geek. I have a bunch of ancient stuff (545A, 547, two 545B, 585A, two 575's etc) and a pretty much complete set of 7000 series scopes and plugins. That is not counting the Fluke/HP cal lab, and a bunch of General Radio stuff. The scopes that get used the most are a 475DM44, a 7904 and a 577 curve tracer. My wife says that there is a very fine dividing line between "collector" and "mental illness". But I'd say that for total flexibility, a 7000-series scope takes a lot of beating - plugins will do just about everything from sampling up to 14GHz, a real time bandwidth of 500MHz for the 7904/7904A, spectrum analyser plugins, etc etc.

Walter Shawlee at Sphere http://www.sphere.bc.ca/test/ was offering a repair service on those IC's. Problem was that they (I think it is the Y amp chip with an integral heatsink) operated very hot, and there was a bond wire failure. Walter used to collect a bunch from people with dead scopes, ship them to Japan where he had found a guy who would take the can off and re-wire-bond them.

Yup. That is the reaction I was expecting

Is there a smiley pop-up window linked anywhere? I can never remember all the smiley's I use off-hand.

All understood and sorted now - I was just being a hardware geek, and not finding the right place to look. All PM history present and correct.

Yeah - I was looking in the right place. Showing zero - so I guess the migration of old PM's failed for me. Reks - do me a favour and PM me something, just so I can veryify I get an e-mail copy too.

Todd - my hat seriously off to you. This looks like a non-trivial exercise to migrate across, so bloody well done. As others have said this new software really rocks along. Can't find my PM history though - am I one of the ones for whom that migration failed? Or am I just not looking in the right place?

WHOOO - well done Andy. A dead Bourns pot was not remotely on my hit list of possibilities - hats off for tracking that down. And hats off to Stax's design and KG's reproduction - seriously robust, both to Andy's wiring problem and once working it seems to stay so (knock on wood...) Looking forward to hearing the report on the sonics!

Nothing much at John-o-Groats, it is just where the land runs out. And no pub. So a pretty unusual place. Yup. That is precisely what we're like - similar to the way that Family Guy portrays us.

It has crossed my mind, but it would have to be 2012 - I've just not got enough time to get that fit this year. But certainly count me in if you have a twinkle in your eye to do this particular ball breaker. My other big goal is another attempt on the Bob Graham Round in the English Lake District. 42 peaks, 66 miles, 29,000 feet of ascent. Has to be done in less than 24 hours. Had a go five years ago, and in spite of being as fit as a butcher's dog, got lost in heavy mist on the summits at 2am, so had to abort. Skiddaw, Great Calva, Blencathra, Clough Head, Great Dodd, Watson's Dodd, Stybarrow Dodd, Raise, Whiteside, Helvellyn Lower Man, Helvellyn, Nethermost Pike, Dollywaggon Pike, Fairfield, Seat Sandal, Steel Fell, Calf Crag, Sargeant Man, High Raise, Thunacar Knott, Harriston Stickle, Pike'o'Stickle, Rosset Pike, Bow Fell, Esk Pike, Great End, Ill Crag, Broad Crag, Scafell Pike, Scafell, Yewbarrow, Red Pike, Steeple, Pillar, Kirk Fell, Great Gable, Green Gable, Brandreth, Grey Knotts, Dale Head, Hindscarth, Robinson. Then relax.

Ah - I'd linked in to the Appalachian trail, for which the stats are correct. Much further from Washington State though. Although there is a Transamerica trail, it is usually cycled. From Astoria Oregon to Yorktown Virginia, 4261 miles. Or the Transameric run, LA to NY next due in 2011. Usually 64 days. Longest leg 59 miles.

Uh - looking that up, it is 2200 miles with 475,000 feet of ascent (er - 16 Everests). Apparently the record stands at about 47 days - or about 47 miles a day and 10,000 feet average. Jeeze. In the UK, you'd have to do Lands End to John'o'Groats, back again, and then return to John'o'Groats to cover the same distance. And you'd never get that amount of ascent.

Yeah - the big ones cover a lot of the country. The longest individual event is the Canal Run Grand Union Canal 145 mile Race - Welcome at 145 miles, from Birmigham to London. I've organised a Thames Path run twice, from the Thames Barrier to the Source, which is 185 miles, but as a relay with individual legs of between 5 and 20 miles. Both these are flat of course. But the US has some of the toughest ultra trail runs in the World that UK trail runners would find really difficult to cope with.

Metabolising fat is a real bugger. Once the glycogen store has gone, and you're in the fat burn zone, it is total misery. I'm a stone or more over at the moment, so I know what I've got coming. I don't tend to use software. If I'm training for something specific like a marathon or some long-distance stupidity I draw up an excel spreadsheet. You can't do any of this stuff without building up and grinding out the miles. Reckon that over the last 35 years I've covered the thick end of twice round the planet.

And that is a solid two weeks. Not counting my semiconductor difficulties the total integrated build time must have been at least 80 hours, and probably a fair chunk more.

Absolutely. Today was just a single mile, partly for the reason you said, but also because I was honestly knackered. Tomorrow as they say is another day. The big thing is psychological - but as (when I'm fit!) I do ultra distance trail running, I know all about the battles with the mind.

Good heavens - I'd missed that too. Must have been amazing to have your exploits immortalised in a series, which was made all the better by the testimony sections where the real guys talked before or after an episode. Still - he made 92, which is not at all a bad age to go.

The building is the fun of the chase. I can't understand desiging stuff for the hell of it without reducing it to practice and testing the design in real hardware. It is a bit like designing a bridge using CAD and FE analysis but not knowing whether the design is fit for purpose. Or am I just being wierd?