Diffuse blue getting difficulty to find these days... you are lucky you’ve got a bag of the good ones! 🙂 🙂 🙂
Diffuse blue getting difficulty to find these days.
5mm Diffused Round Top LED - Blue
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3MMLED-BLUE: Jameco Valuepro : LED Super Bright Blue Diffused 3mm (T-1) 465nm 5000mcd : Opto & Illumination
XLCBD12D: Sunled Corporation : LED Blue Diffused 5mm T-1 3/4 460nm 995mcd : Opto & Illumination
LL-50ABD2E-017: Jameco Valuepro : LED Blue Diffused 5mm T-1 3/4 470nm 350mcd : Opto & Illumination
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did I told ya that I spotted at Pa's biiiiig box of Sylvania 6DJ8, and - when I asked for what's that, he said - some nice project for Greedy Boyz.....
of course that I stole two dozen of these, too

of course that I stole two dozen of these, too

did I tell you that I spotted.. some nice project for Greedy Boyz .....


Found the reason for unique uniqueness of Sound of all Papamps!!
he's using diffuse blue LEDs in front!
😛
You're absolutely right! The first blue leds that I ordered weren't diffused and my amp sounded harsh. When I replaced them with diffuse leds the aural image snapped into focus, the background became black as night and the musicians sounded as if they were in my room! I could almost smell their boozy breath!!!
Diffuse blue getting difficulty to find these days... you are lucky you’ve got a bag of the good ones! 🙂 🙂 🙂
Who would've thought diffuse leds would become unobtanium? Papa does like those esoteric parts!
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At a local surplus shop, I found some early SiC blue LEDs. Unlike the current GaN variety, they have a pleasing sky blue color rather than the aggressive shorter wavelength blue (I get tired of seeing them everywhere...). The SiC LEDs aren't all that bright, but I'm using them as pilots rather than illuminators, so I don't care. I may use one as a pilot on my latest project, a headphone amp that will also find life as a ~5W/channel Class A amp. the board you see below biases up with ~1 mV offset. Next up, I need to take it down to the basement and tickle it with a function generator to see if it actually makes noises like an amplifier. I'm using a new position for compensation that worked well in simulation, but you know how that goes...
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For a fascinating description of the first blue LED (GaN) and the Nobel Prize which it received, have a look at Wikipedia
Shuji Nakamura - Wikipedia
Shuji Nakamura - Wikipedia
SiC blue leds preceded GaN, but the efficiency and easier processing of GaN kicked SiC summarily to the curb. Cree was a producer (looking for a market to flog SiC technonogy - they have a better one now), as well as Liteon.
We have an Audio Precision Sys2 at my work place used to measure spurious audio from power supplies. It has a pathetically dim sickly greenish blue (kinda bluish cyan) pilot light that I suspect is an old SiC "blue" led.
For a fascinating description of the first blue LED (GaN) and the Nobel Prize which it received, have a look at Wikipedia
Shuji Nakamura - Wikipedia
Interesting wiki. Thanks for the link.
It's nice to see that Nakamura hakase is now at UCSB. 🙂
It was almost unprecidented that Nakamurra was able to put those basic patents in his pocket and walk away from Nichia. These days he's mostly working on GaN active devices - not the only one, either.
The company I work for has shipped more GaN active devices than everyone else on the planet combined...
Cool news !

Time to test them or ready done ? Hfe, leakage etc.
yup
just lacking some time.....
working these days to finally finish one Iron Pumpkin SE, for Bob's My Uncle
hope Plains soon starting their Pony Express duty ......
just lacking some time.....
working these days to finally finish one Iron Pumpkin SE, for Bob's My Uncle
hope Plains soon starting their Pony Express duty ......
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