Craig Sawyers

I'll have to check that my router does not have a grandfather clock

That is a watch made for Marie Antoinette. Took 45 years to build from 1782 to 1827 at which point Antoinette had been 34 years dead from the Guillotine. The work was partly done by the original Breguet, and finished by his son after his death. There are currently two of them. The original was stolen, and Breuget (still in business!) made a duplicate, which even with the original drawings took them three years to build. Then the original was recovered - and is currently insured for $30m. One of the most famous watches in existence, and a thing of real beauty - particularly when you consider it was completed nearly two centuries ago.

Miss Atomic Bomb 1957

Nice looking set up. Quad power amps - don't recognise the deck - a Linn? And what is the pile of stuff behind the left speaker? Sub amp and mains regenerator?

That is awesomer than my anecdote for the night. Went to see Amanda McBroom http://amcbroom.com/ this evening in London. Been listening to her music for decades. I went and said hello afterwards and got a cuddle. Seventh heaven! But McCartney - wow!

Apart from the 2SK170/LSK170 the lowest noise n-channel FET I've found is the BF862 with 0.8nV/rootHz. This is a 700MHz surface mount device and is made in the bucket load, and is a factor of several cheaper than the LSK170. The key it seems is to chose RF devices in which noise sources with low impedance drive (like an antenna) are important. Difficulty of course is finding complementary devices - the closest are the current offerings from Linear Systems. At least they do the LSK389 - if they eventually produce the LSK109 (they took long enough to crack the LSJ74 fab problem!) that would be nice indeed.

Happy birthday - have a great one!

Well that was seven kinds of awesome.

Analog Devices (actually now TI) just announced the obsolescence of the lowest available noise biplolar parts - pnp matched doubles with a noise of <0.7nV/root Hz and 1/f corner of 3Hz - SSM2220 and MAT3 http://www.analog.com/media/en/PCN/ADI_PDN_16_0034_Rev_-_Form.pdf . The MAT12 is still current, buy eye poppingly expensive in a metal can only. These have a noise equivalent resistance of about 30 ohms. The only thing I know of that used to have lower noise was the late lamented Rohm 2SB737 with <0.4nV/root Hz and <10 ohms equivalent resistance. That was just too damned useful to survive without being discontinued. Lots of fake Chinese stuff out there. Also the On Semi 2N5087 low-ish noise PNP is now obsolete too. What have manufacturers got against audio?

Repair goo only works if you have a slow-ish leak. When was the last time you had a slow leak? Every tyre that has gone on me in recent years has been a hole in the road shredding the tyre beyond goo. An X5 has no spare? WFT. You're right to ditch run flats though - see above comment on shredded tyres. They are an expensive useless nonsense.

Happy birthday!

Is it too late to order a pair of Golden Reference boards?

I've checked with all my usual suspects on the bookshelf, and the only thing that I can find relates to minimising DC offset - in a unity gain buffer fed by a source with output resistance R, you put R between output and inverting input - so the same bias current flows into both inputs and hence minimises output offset in a simple way. Why would it act as a bandwidth limiter?

Was looking forward to black pudding with a poached egg on top, with bacon, post run. But there was (boo hoo) no bacon. So I had to make do with black pudding with poached egg - which was still awesome.

Now that I have not tried. But I did go for a plate of duck gizzards some time ago in France - rather weird but not at all as bad as it sounds.

The miniDSP's seems to be well thought of, and astonishing value form money for the 2x4 (available either single ended or balanced), which is all you will need to integrate subs with whatever. The miniDSP range are the ones that Linkwitz now uses for all his current speaker designs - he has discontinued support for the analog active crossovers. I don't know what the Hypex one is like, but their class D power amps seem to have a strong following.

The only thing in common is puppets - different quality and storyline, and age it was aimed at. As was its Supermarionation precursor out of the Andersons, Fireball XL-5 (made at the same time as Hoppity - very early 60's) The single legged Chucky-like Hoppity was aimed at the same very young audience as similarly naff things like Andy Pandy and The Woodentops. The one that was half way decent out of the same stable as Hoppity was Space Patrol. So yes - I did watch Space Patrol, Fireball XL-5 and Thunderbirds. In a sense it was almost inevitable that many decades later I would spend five years managing a space instrument project (MIXS - the Mercury Imaging X-ray Spectrometer), due for launch next year. But even when tiny I loathed Andy Pandy with a passion.

It apparently ran for 52 episodes following that pilot. I was 4 to 6 years old when it ran, so I must have been right in its target audience. Fortunately I have no recollection of this puppet nightmare.

Depends. I used big Fischer heatsinks on my power amps, and the mounting face was pretty banana shaped - actually fairly typical of big section extrusions. Took quite a bit of work to level them (all 8!) - abrasive paper taped to a glass plate. But in fairness to Fisher, they say that if surface flatness is important they should be machined flat (which they offer to do - for an undisclosed price). But polishing isn't really necessary - heat sink goop fills in minor surface irregularity. But I did not flatten my T2 heatsinks, and have not had any problems.

When I was 16 I discovered the difference between rms and peak by using a capacitor across a mains switch of an amp I had built. BANG. That was the first in a catalog of stupidity over the decades - the last was destroying quite a lot of my Tektronix 577 curve tracer by plugging the power supply back in with the connector one pin along. Fist I knew I had a problem was when the top of a 741 op amp blew across the room smoking. Still repairing that......

Careful of the feedback paths, particularly since it goes over two boards with I would guess wires to connect. The T2 is prone to oscillation which can be quite tricky to sort out. The thing you have going for you in this regard is the compactness with SM. Why go to the trouble of mirroring? If you have a layout that works, you might well run into problems with a mirrored version with different tracking (since active devices themselves do not mirror).

Well the thermal resistance seems to be pretty constant from lowish torque (at least from the graphs in the apps note). The importance is that it stays put as temperature changes and polymer materials (like the AAVID insulation washer) creep with time under pressure and temperature.