John Curl's Blowtorch preamplifier part II

[dvv]

If the Blowtorch has no blue power on LED, it can't be high end. Just ask the Chinese, I think their toilets have blue LEDs.

 

[marce]

Blue is horrible in LED indicators far to bright and distracting, white is OK if its not blinding, but green and red are my favourites...

 

[billshurv]

HP green in particular (showing my age here)

 

[jacco vermeulen]

I'm talking late seventies here BTW.

As an analogy : life expectancy of a diesel engine is pimarily governed by the average piston speed. Second factor is the power rating, a higher turbocharged engine with identical max continuous rating rpm has a shorter longevity.

White and blue LED's have a short wavelength => high energy.
High energy => higher rating => shorter life expectancy.
Decremental steps are nominally larger than long wavelength LED's as e.g. RED lightning, aka visually fade away much faster.

I have a device with red LED's which has been running 24/7 for 3 decades, 265k hours minus a couple of bridge&dumpster adress switches.
Without a measurement, I can't honestly tell if half-life has been reached.
Yours truly, dr J Hick.

I have to start getting used to adressing you as Mr. Mr. Russell, Mr. Russell.

 

[billshurv]

Although if you read Ricardo he points out that mean piston speed is fairly constant from RC engines down to cathedral diesels.

 

[AndrewT]

............
I have a device with red LED's which has been running 24/7 for 3 decades, 265k hours minus a couple of bridge&dumpster adress switches.
Without a measurement, I can't honestly tell if half-life has been reached.
Yours truly, dr J Hick..........

My oldest LED is probably the channel indicators in a Quad FM4 tuner.
Might be getting close to 30years old and never a problem with any of the green LEDs.
stays on 24/365 and most of the time shows station 5 LED, probably approaching 100000hrs.

 

[jacco vermeulen]

Green LED's have a wavelength inbetween white and red, but low forward voltage.
Life according to hick would assume a green LED has an average life expectancy : a greenie beats a blue meanie, but loses from burning chili peppers (red+yellow).

 

[jacco vermeulen]

probably approaching 100000hrs.

[24/365 times 30 = (24/3)x(365x3)x30~8x1100x30= 8x3x1.1x10k= 264k~265k]

 

[marce]

What is the wavelength of white light Jacco

 

[jacco vermeulen]

Don't know, I use so much whizz, I have to wear sunshades (24/7)

 

[marce]

LOL

 

[jacco vermeulen]

Please excuse my current bad temper, Mr Marce.

Afaig, a white LED basically is a blue meanie on meth.
Does a white LED have a wavelength ? (white light isn't a color, but a mix of illegal refugees)
But I get your point.

 

[AndrewT]

[24/365 times 30 = (24/3)x(365x3)x30~8x1100x30= 8x3x1.1x10k= 264k~265k]

the 5th of 8 might only be on for 30% to 50% of the total ON time and maybe some unknown Tuner OFF time.

 

[marce]

Sorry couldn't resist...
On a more serious note, when I thought about it, I would presume its a broad spectrum of wavelengths that excite our S M and L receptors.

 

[AndrewT]

I thought that blue and white LEDs were more likely to be UV LEDs with a range of visible light phosphors to give a mixture of discrete wavelengths that together mimic whitish light.

Much like colour television and fluorescent tube.

 

[jacco vermeulen]

the 5th

The logic of 100k escaped me.

(you're the principal advocater of accurate English on English forums/fora/fore/fori)

 

[AndrewT]

I typed 100000hrs. I thought that would be universaly recognised as 100000hours.

 

[AndrewT]

The logic of 100k escaped me.

(you're the principal advocater of accurate English on English forums/fora/fore/fori)

I support attempts to write accurate technical english on a technical Forum.
Otherwise we are left guessing at what ambiguous statements might mean.

Spelling errors can be excused, lack of english due to being a non native language is excused.
gobble de gook written to save time can never be excused.

 

[jcx]

white LED are often visible blue with just 2 extra phosphors to make white

but the blue can be annoyingly shorter wavelength than needed by the eye


in bias operation the LED can be operated way below the rated current that the nominal life is given for

 

[johnferrier]

I had almost forgotten that this is what the thread started as.

Ten year anniversary of the two Blowtorch treads coming up this January.

7th January 2006 . . .

Hello,

For years, I collect all the documentatons, informations, schematics of the best audio designers and products. I possess many of the great brands.

The Blowtorch is the only preamplifier to do the unanimity with the audiophiles of the whole world, even for the tubes fans. Also, I am very interested by this preamplifier.

The Blowtorch preamplifier is the work of CTC Builders (Curl-Thompson-Crump). John Curl creates the electrical designs, Carl Thompson engineers the board designs, and Bob Crump chooses the parts.

Unfortunately, Bob Crump has just died at the end of 2005. With his kindness, I had been able to recover some information.

I believe that this preamplifier was built with less than 40 specimens and is not even available in Europe.

I search just in a strictly personal purpose and not commercial ; all the possible information, specifications, synoptic, diagram, schematics, inside pictures, on the Blowtorch power supply and line stage.

Thank you

Best Regards

Darry