Mend it Mark takedown.

[DrStrangelove]

Does it comply with the "China Export" definition?

Just askin' for a friend.

I well recall the joy of CE testing.

I wonder how well it responds to the sparky thing and the transmitter thing.

I'm so glad I don't have to do that sort of thing any more.

[Craig]

I guess it could stand for Cymru Export....

Craig

[BusyBee]

Of course it has now got more complicated anyway with CA markings https://www.gov.uk/guidance/using-the-ukca-marking

[Mark Hennessy]

Not really, as the UKCA scheme has been effectively abandoned. The CE mark will be recognised in the UK indefinitely.

https://www.gov.uk/government/news/uk-go...businesses

[ppppenguin]

Not immediately relevant to this thread but since we're on the subject of "China Engineering", MK have been caught out:

https://www.gov.uk/product-safety-alerts...-2411-0130

[Mike Watterson]

That's is what happens when a previously top company outsources "Don't own the mill only market" and doesn't do QA. How did they ever pass test?

[Craig]

I use MK logic plus double switched sockets, which I think are still made in the UK.

Since I installed them, MK have introduced screwless terminals, which seems to be a really positive innovation.

Craig

[DrStrangelove]

I guess it could stand for Cymru Export....

Craig

ROTFLMFAO.

Indeed to goodness, boyo, so it could. 

From the valleys too. 

[Diabolical Artificer]

I've been watching this unfold & commented on the original video echoing Jeremy's comment about putting tantalum caps across power supply rails as tants fail SC as seen in vintage Tektronix scopes etc. I also had a swipe at the "genius at work" caption on Tom's website. In fairness though Tom may have written that with tongue in cheek. We're Englishmen, we don't blow our own Trumpets, the American's do, they also go woohoo a lot instead of politely clapping.

I read Tom's response, there's always two sides. Regardless, packaging heavy items is an art & also an engineering exercise, not everyone is good at it as we all know.

As to design of the preamp, I can't comment, the 25 grand price tag is excessive to most of us, but there are other factors in play. As a very minor maker of valve amps I know how much work goes into making them & how hard it is to sell them to cover my costs. I've lost money on every one, but I build amps for the love of it, not as a business. If you do want to sell hifi amps in the low numbers a one man workshop can make, like all things in this world you need spiel, some blurb to make your product stick out: it's the way of the world. Yes we know most of it is BS, but a bloke with 25 grand to spare & who doesn't know a long tailed pair from a differential IP.....

I think all the waffle on YT & elsewhere is just the same old righteous indignation we humans like to engage in, we love to have a good old moan. Ce la vie.

Ho ho ho, have good un, love & peace to you all, Andy.

[Craig]

As far as tant bead capacitors go, it is all to do with headroom. Back in the day, when I was designing equipment, I used lots of tantalum bead caps on the power rails. The data book said to use 6V parts on 5V rails and 16V parts on +/-15V rails. They made those voltage ratings at common rails +1V for that reason.

If any of my designs is still in use (and this was mil-spec gear) I can absolutely guarantee those caps will be failing short circuit now, after 40-odd years.

Provided that you use capacitors with enough headroom >>1V I suspect they will be reliable enough. So 10V rating on 5V rails and 20-25V on 15V rails. I do not know what voltage rating was used on the £25k phono stage.

I think it is telling that Tektronix went from using immolating tants to electrolytics in later production. As an example I have several 7A26 dual trace vertical amps, some with tants and others with aluminium electrolytics, fitted from new. But they followed the rail +1V for their tants. And astonishingly a 50V tant bead on the 50V rail. No prize for what happens to that part.

Craig