John Curl's Blowtorch preamplifier part II

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Sounds like you're on the suppliers side, rather than yours ! ?

Maybe you should order you parts from a UK supplier instead !

I'll do that when I decide to commit an economic hara kiri. UK suppliers are at least 40% more expensive than most German suppliers for German made goods, which Wima caps are.


12 months is standard in the UK. I've had no problem returning faulty parts to them & other suppliers in the past, within 12 months.

It's kinda hard for me to do the same when a filter fails and happens to be in Hong Kong or on New Zealand. The shipping costs are like 250 times bigger (both ways) than the price of the failed part.

And my prime obligation is to my customer. I might end up making €1 on any unit, but I will honor my warranty in spirit and to the letter even if it makes me lose money. Customer is God.

To be fair, I must admit that despite the shortened warranty, for the last 12 years, only one (1) unit failed in the field. Most fortunately for me, the owner, a gentleman from Hong Kong, was an electrical engineer who said he'd change the cap, and I said I'll prolong his warranty for an extra year. We still write to each other on occasion, and he did send some trade my way.

Actually, reliability is why I am so strongly biased towards Motorola/ON Semi. In all my active life, NOT ONE of their components (transistors) has ever failed me and was to blame. Not ever! And I know of quite a few examples when they damn well should have failed, but didn't.
 
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You guys worry about the smallest things: Of course, caps sometimes fail. Even REL RT Polystyrene caps sometimes fail, and it has cost either the customer or me, or both of us, a significant cost in repair, as other parts fail then, as well. So be it.
I know of guy, who bought a brand new Porsche dual Turbo, about 15 years ago, who lost a tire, and he had to replace it without warranty. He was upset, too, as each tire cost about $500 at the time, but still, the tire failed even on American roads, and our very low speed limits. Even the best efforts fail sometimes.
 
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If you had any experience in quality measurements,

You know nothing about what I have done or do or will do in that regard but then I don't boast on audio forums, I prefer to assist people instead. You might try that sometime.

you would know that it takes man-months of effort to do anything interesting.

It does? Interesting means what, making excuses up when the results don't match expectations or actually doing the tests?

I am just learning the equipment at the moment.

Take your time, maybe you will get to flipping that on/off switch before the warranty runs out.
 
You guys worry about the smallest things: Of course, caps sometimes fail. Even REL RT Polystyrene caps sometimes fail, and it has cost either the customer or me, or both of us, a significant cost in repair, as other parts fail then, as well. So be it.
I know of guy, who bought a brand new Porsche dual Turbo, about 15 years ago, who lost a tire, and he had to replace it without warranty. He was upset, too, as each tire cost about $500 at the time, but still, the tire failed even on American roads, and our very low speed limits. Even the best efforts fail sometimes.

No argument here, John, but I was pointing out the dichotomy that it was I who was being forced to upgrade what I see as an inferior warranty. To be sure, I still do it, but it's still not fair.

After all, we're not talking of something made by Foo Manchoo Plastics Corp, we are talking about what is supposed to be a world class company. Kensonic Accuphase actually touted using Wima caps in their sales literature some years ago, and they sure ain't no cheap trick.
 
David, gve it a rest. John is right, doing a good and valid measurement takes time, care, and deep familiarity with the ins and outs of the particular equipment.

Months huh? What is he planning on testing that takes that long? Yeah right.

From his past "results" what hope is there for him doing it right anyway? He ignores all help and bulls his way towards invalid test procedures.
 
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SE, you don't have sophisticated test equipment, how would you know?

Instead of resorting to your usual ad hominem attacks, why don't you explain why it would take anyone MONTHS to do a simple distortion measurement on a cable of all things.

Did it take you MONTHS to do the tantalum capacitor measurements you were waving in everyone's face a while back? I don't think so.

Give me a break, John.

I suspect that your new toy isn't giving you all that distortion your ST-1700 was spewing out (which you recently said you still stand by) and now you'll have to try and explain where those diodes in the wire up and disappeared to.

se
 
Instead of resorting to your usual ad hominem attacks, why don't you explain why it would take anyone MONTHS to do a simple distortion measurement on a cable of all things.

Not to speak for John, but for some of us, getting the time to get a good measurement is not trivial. I have some clean-up stuff to do for my latest article and haven't been able to get to it for a month now.

Look at this as a positive- perhaps he's trying to get things right. If not, well, there will be plenty of chances to do peer review. :D
 
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