John Curl's Blowtorch preamplifier part II

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Do you recall what the temperature coefficient of the output voltages are? There should be partial compensation of the error amp input voltage by the probable tempco of the 2SK170 current generator.

If simulated with the temperature changed for all components in the same range the ps regulator has negative output voltage tempco, If the temperature was changed for CCS and shunt mosfets then the tempco is very close to zero.
In the built regulator there is some increase in the output voltage with the temperature (I don't remember how much, the CCS and shunt mosfets are bolted to the same small heat sink), but the preamp is not in the box yet and influence of the 2SK170 tempco is small.
 
You mean he didn't already ?
In some other forums this thread is an object of joking and reference to something extremely long , boring, fruitless and self-promoting.
Oh, I had learned a lot of things, here. Sometimes, a simple word, in the middle of a sentence, that open my mind.
There are real experts, in this thread. Never found elsewhere at this level. And you know how they are, sometimes very second degree, sometimes too serious... And a lot of various experiences...
Extremely long, for sure, like so many nights in your favorite private club.
Boring, sometimes, passionate at other moments. Life is so.
Fruitless ? Oh Lord, NOT.
Self promoting ? I want to be loved by YOU.
...And ... you know the first rule about the fight club ?

[Edit] Oh by the way, don't expect anything about Blowtorch preamplifier, here. What did you hope ?
 
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Hi Esperado,
There are real experts, in this thread. Never found elsewhere at this level.
I couldn't agree with your statement more! There is lots of excellent knowledge sprinkled throughout this thread. The nature of the discussion prevents all that wonderful information to be condensed into a smaller thread.

Hi gerhard,
Thank you for the LED information. It's nice when it is all tabulated nicely. I use LEDs a lot in power supplies, so the information you posted will probably be useful.

-Chris
 
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Perhaps, we're at the 7th rule . . .

Excellent post BTW (IMHO).


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Yes. I tested this a few years ago with a high intensity strobe.

Of course, bias LEDs are mounted inside the case...

Why would you actually *test* such a thing? It reminds me of the architect that wanted to place a light behind a 1" thick slab of marble, and have it shine through. He suggested a 60 watt bulb ought to do the trick. He was so convinced, he tested it. Result: The marble blocked the light. Boy was he surprised!
 
Sorry for saying this but surely Sy doing some measurement's on LED's is helping Audio reproduction, helping to dispel myths and allow people to concentrate on the real problems in Audio reproduction not the fantasy esoteric side, who's supporters and promoter's are doing the opposite and helping create an image of audiophiles that is not the best...
I am sorry you go out of your way to rationalise some of the silliest components I have ever heard off yet condone scientific experimentation and testing....:confused:
Next you'll be telling me cables need breaking in.......:D
 
Thanks SY, I can understand the motivation, but really.... who could be so stupid/ill informed to think that an LED inside a sealed enclosure is going to be affected by flashing a light at the enclosure?

I mean you don't even need an education to see how ridiculous it is to think it would have an effect.
 
Thanks SY, I can understand the motivation, but really.... who could be so stupid/ill informed to think that an LED inside a sealed enclosure is going to be affected by flashing a light at the enclosure?

I mean you don't even need an education to see how ridiculous it is to think it would have an effect.

Perhaps not, but it's something I run into again and again. I think, as Brad alluded, that the well-known photon-induced leakage when reverse biased confuses people.
 
I am sorry you go out of your way to rationalise some of the silliest components I have ever heard off yet condone scientific experimentation and testing....
Sorry, but I think you misunderstood what BigE was telling.
You are both right. It is ridiculous to measure the sensitivity of a component to light... in the total dark. Unless you want to measure its sensitivity to the cosmic rays ?
In the same kind of idea, I did the same, the first time appeared golden metal cones to be put under our "solid state amplifiers". Hitting the amplifier with an hammer and recording its output.
Oh, it is not a bad method to figure out bad electrical contacts :)
 
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I can just see the crazy audiophile advertisement already how they would shield the individual internal leds so that one does not affect the other through mutual coupling! Anything we can see as obviously a false premise is foisted upon the true believers who want to believe the nonsense, what are we to do about stupid people who want to believe in aliens doing anal probing! Let the buyer beware, to bad most buyers can barely figure out the cost of a piece of fruit.
 
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