Craig Sawyers

That Al does sound really awful. But Doug's comment for some reason made me think of Dr Stragelove....

Well, I tried and failed to get the beast finished before wife and daughter got back from Rhodes. What I do have now is all four Amphenols pigtailed and installed in the now completed chassis. With that in mind, you have to leave the Amphenol fixing screws loose, plug in the umbilical to centre the chassis connector in the hole and then fully tighten the nuts. So only the internal wiring to complete now.

Ah - you spotted that lurking in the background

Just the Amphenols to wire up now http://www.tech-enterprise.com/tekstuff/P9070512.JPG http://www.tech-enterprise.com/tekstuff/P9070513.JPG

Over the years so many useful devices have just vanished. Dangerously unprotected MOSFETs from Siliconix that were essential in certain CCD designs - long dead (came with a wire clip shorting the leads together. Solder in and then remove clip). Sensible dual FET's like the 2SK389/2SL109 - dead. Now pretty much the only 900V PNP - dead. Next on the death list will be components with leads, with surface mount being the only game in town. Lead free solder? A complete sham, which subject I can wax lyrical on at length. One audio manufacturer I know has a reel of lead free solder on the bench for audit purposes, and then uses Wonder Solder or some such leaded solder in building the gear. Don't even get me started on the name change game - Hitachi to Renesas, Motorola to ONsemi, HP to Agilent to Avago. Without even considering the number of useful products that have gone the way of dust as a result of Vishay's quest to own every brand going - then doing "product rationalisation". <soap box mode> = "off"

OMG - I've just been trawling Sanyo's various sites, and eventually found the discontinuation notice Discontinued products property Dead for good at end December 2010, with final order submissions by end September. Good job I had enough stock for the BH; and thirty odd lurking in a bag recovered from an aborted project (don't ask).

Goddit!

?? On other topics, I was merrily torquing down the devices on the amp board, with the torque screwdriver set to the correct value of 1.1Nm for TO220 packages. I then moved on to the 2SA1486's - and promptly split the first one in two. Then I checked - the maximum torque for a TO126 package is 0.4Nm, and use of a washer under the screw head is recommended to further spread the load. Taking those remedial actions all is OK. By the way, I have gone back to using steel screws, but with the Aavid 7721-3PPSG bushes. These have a 3.18mm (1/8") shaft, which goes pretty much all the way through the 4171G ceramic insulators. The steel screws mean that you can get the torque set for maximum heat transfer (with heatsink grease too of course). The 7721-3PPSG is a slip-fit in some device holes and a tight interference fit in others - tolerance stack up I guess. Also, they cannot be used for metric screws because the hole is not quite big enough - so for that insulating bush those of us in metric countries need to get hold of the imperial 4/40 screws and nuts specified in the BOM. What I am doing with the 2SA1468's is to put a 4.7mm length of heatshrink over the threads of the 4/40 screws. This makes a nice fit in the device hole. 4.7mm goes most of the way through the ceramic insulator.

I got mine from Future Electronics.

Geez - I've just spent five hours (a) fitting the DACT and ( fitting half the transistors to the heatsinks (just the 20-off c3675's). Gotta get it more or less finished tomorrow - wife and daughter have gone to Rhodes (I hate hot holidays; I'm a cool climate guy) so I've been using the week as play time. They come back Wednesday, and will expect to find the house not looking like an electronics production shop floor.

Geez - no wonder I couldn't find it! The really stoopid , shot in the foot thing is that quadsunlimited was credited a few posts down. In fact the whole discussion was very pro the work he'd done in stacking. Feels kind of different now, doesn't it?

Apart from the fact I cannot find the mail from John Buchanan to which you are objecting, what precisely is your point? Whichever way you look at it you just got free advertising. And just to be perfectly clear, did you join this forum to make just that one post?

Whohoa! Power supply lives. Just went for broke, screwed the whole shebang into the casework, wired it up and turned it on. Unloaded volts are just about bang on. Haven't checked for ripple yet Now the question is - do I dummy load it, or just go for broke and build the amp up?

Rigoletto. Series of live performances from the locations that Verdi set the opera in, in Padua. Placido Domingo as Rigoletto, with remote orchestra conducted by Zubin Mehta. First act was last night, second was midday today, and final act tonight at 10:30. Amazing. I watched a similar exercise around 20 years ago of Tosca, again with Domingo, set in the correct settings around Rome. Final act was 4am - that one needed some stamina to watch.

There are some versions of the BOM lurking earlier in the thread. But I'm a relative newcomer to this electrocution-grade amp thread - I've been concentrating on KG's ultimate madness - the T2. Just got the power supply board and three transformers mounted in the power supply chassis. Without the front and top it is nearly a hernia lift - it is Krell-like mass, must be 30lbs+. And then there is the amp.... That animal operates from +500 to -560V rails, plus others at 250V, -260V, +/-12V. I'm really taking my time and doing the build with real electrical best practice - there is just no room for error, or getting a finger in the wrong place. But somewhere not too distant down the line, I'd like to have the option of building the KGSSHV - hence the request for a board set. I has just got to be cheaper and easier than the T2, which runs to several thousand of whatever currency takes your fancy, and more construction hours than a sane man can safely contemplate.

Massively off-topic, but..... A branch of my family did just that, in 1921. Looking forward to a life in the coal mines of North East England, Adam McKinght uprooted his family (wife and two children) and off they went to Vancouver. And there that branch of the family live to this day. Actually 80 years previously to that, his grandparents escaped from Ireland just at the start of the potato famine in the 1840's, and found their way to the NE to become coal miners. Given these traumatic events, I'm sure they ended up with a much better life (Adam McKnight opened a general store in Nanaimo; better for sure than hewing coal). And yes - I got heavily into family history a few years ago.

Nah - I couldn't cope with imperial measurements on a day to day basis

Yes - because the part is made in the US, then has to travel several thousand miles to get to Farnell. So I can either buy at half the price from Digikey, then pay shipping to the UK plus tax, then wait a week for them to arrive, and then drive 40 miles round trip to collect from Parcel Force to pay the tax. Alternatively I can get them the next day from Farnell, cheaper in overall terms (no 40 mile round trip etc etc). The only place that really has international trade sorted out is Mouser. They have arranged with UK customs to charge tax in advance, then offer free shipping for orders over $100. On a big project, peppered with Dale resistors and other fancy stuff, I can order on line and the damned stuff arrives from the US through my mail box two days later. Digikey has something to learn.

So I understand from KG - so that is what I've done. I think he's updated the PSU schematic to include all this stuff - usual link. Took more than half an hour to find my 1/4" crimp receptacles. Aagh.

Plus the 10k resistor between the voltage reference and pin 2 of the OP27.

Who was that? Dalbani/Nikko or some other one I haven't found yet? That price seems very good. OK - I'll bite - put me down for a set. After all, how many KG designs does a man need? Um, how about a full house.... In the UK Farnell stock them (at least if we're talking Aavid 6300BG), their part number 1213471 at

First things first - welcome back! I've done the mod, board bolted to heasinks, just wiring in the transformers. Hopefully later today this puppy will get fired up.

Um - surface area of Britain (England, Wales and Scotland added together) is 94,000 square miles. The USA is 3,718,000 sqare miles - so you could fit 40 Britains into the US. Texas alone is about three times that of Britain at 262,000 square miles. We're about the same surface area as many individual States (Wyoming, Nebraska, New York etc). Except we have 60,000,000 people crammed in. If you take just England the comparison is even more extreme - England is a truly tichy 50,000 square miles, about the same size as Pennsylvania.

In the UK you cannot drive for that length of time without ending up in the sea (assuming you don't drive in circles) - even Lands End to John'O'Groats. The record for cylcing the 874 miles is not much more than twice the number of hours you drove yesterday - 41 hours. But I've driven many times in the USA, and it is bewildering how long you drive for and hardly make a dent on the country.

Been there, done that, got the badge.