"Where did you get those MJ15015 at that low price?
Are you sure they are not fake ?"
I bought 300pcs each of 15015/15016 for $1.23/$1.30 from the factory authorized distributor.
The current low demand on those part numbers has increased the price.
Are you sure they are not fake ?"
I bought 300pcs each of 15015/15016 for $1.23/$1.30 from the factory authorized distributor.
The current low demand on those part numbers has increased the price.
For sure, connections that look pretty when new, can fail later. Generally, anything that didn't have physical support, such as tying, glue or bolts, probably will come loose. Other than that, it is really hard to predict what may come loose after a number of years. After six years, I have had two things come loose. They were still shiny, pretty, clean, but not attached!!!
Very interesting - thank you very much. Please let me know the year of release from the mentioned book so as the number of picture in post #69.
If I look in magazines from this year, I must actually find an early advertisement of the 2N3055.
Prof Kaneda 3055
Prof Kaneda in Japan is also a big fan of 3055, he has published many amplifiers
Amplifiers
ƒoƒuƒ‹Šú‚©‚ç‚ÌDCƒpƒ��[ƒAƒ“ƒvƒVƒŠ�[ƒY ˆê——•\
PSU
ƒoƒuƒ‹Šú‚©‚ç‚ÌDCƒAƒ“ƒvˆÀ’艻“dŒ¹‰ñ˜H ˆê——•\
the 209 is 10 W, outstanding Kits Kaneda
BR
Jean-Louis
Prof Kaneda in Japan is also a big fan of 3055, he has published many amplifiers
Amplifiers
ƒoƒuƒ‹Šú‚©‚ç‚ÌDCƒpƒ��[ƒAƒ“ƒvƒVƒŠ�[ƒY ˆê——•\
PSU
ƒoƒuƒ‹Šú‚©‚ç‚ÌDCƒAƒ“ƒvˆÀ’艻“dŒ¹‰ñ˜H ˆê——•\
the 209 is 10 W, outstanding Kits Kaneda
BR
Jean-Louis
Interesting circuits - thank you. The last is similar to this (maybe the predecessor):
http://peufeu.free.fr/audio/schemas/Kaneda_Mosfet.jpg
more circuits with this topology from last URL (Message #199) are listed by number 1 (post #1) under
http://www.diyaudio.com/forums/soli...better-audio-non-complements-audio-power.html
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More details I have found there:
http://www.introni.it/pdf/RCA Transistor Manual 1964.pdf
Vox Solid State amps - transistors
concerning 2N3055 check out post #112-118 under
https://www.diyaudio.com/forums/sol...ary-ab-bipolar-amplifiers-12.html#post5378924
https://www.diyaudio.com/forums/sol...ary-ab-bipolar-amplifiers-12.html#post5378924
A lot of information has already been gathered here - thank you therefore.
But I am still looking for images of a genuine brochure and advertisements from old electronic magazines when RCA's 2N3055 was announced and released in the early 1960's.
Maybe in one of this magazines
HIGH FIDELITY - Consumer audio and music magazine
RADIO and BROADCAST HISTORY library with thousands of books and magazines
as well as in advertising letters that were sent by RCA to the consumer/professional electronic industry (home-audio) at the time.
Now I have found this datasheet - go to the attachment.
also of interest are this German website (for overview of all showed 2N3055 versions scroll down):
RCA 2N3055 (1973 / hometaxial)
The explanation of hometaxial vs. epitaxial process together with the associated images is very interesting - so I think.
This URLs are also of interest:
The RCA 2N3055 transistor
Watt's Up?: Early Power Transistor Evolution, Part 1, Germanium
Watt's Up?: Early Power Transistor Evolution, Part 2, Silicon
But I am still looking for the first commercial advertisements (announcement) so as brochures/flyers opf the (at those days in th early 60s brand new 2N3055) from RCA
Attachments
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Hi,
A contact at Lambda had told me years ago that the original 2N3055 was developed by them specifically for power supply pass transistor use. The original ft was 19 KHz to avoid oscillation mounted away on a heat sink.
You might want to chase that down.
A contact at Lambda had told me years ago that the original 2N3055 was developed by them specifically for power supply pass transistor use. The original ft was 19 KHz to avoid oscillation mounted away on a heat sink.
You might want to chase that down.
@tiefbasseubertr - any luck finding that 2N3055 advert yet?
The first I saw was in the 70's, from a magazine, but I think, if I recall correctly, it was from someone's archive and the mag. may have been 1964-1965.
It advertised the 2N3053, 2N3054 and 2N3055 as a "new range of power transistors" from RCA.
I have tried unsuccessfully to locate the image of the three devices, which showed the TO-5, TO-66 and TO-3 cans.
I contacted one of the magazines which it may have been in, but they only had hard copies (not digital back then). I did not have time, at the time, to take up their offer of browsing through them and don't know if they are even still going.
The first I saw was in the 70's, from a magazine, but I think, if I recall correctly, it was from someone's archive and the mag. may have been 1964-1965.
It advertised the 2N3053, 2N3054 and 2N3055 as a "new range of power transistors" from RCA.
I have tried unsuccessfully to locate the image of the three devices, which showed the TO-5, TO-66 and TO-3 cans.
I contacted one of the magazines which it may have been in, but they only had hard copies (not digital back then). I did not have time, at the time, to take up their offer of browsing through them and don't know if they are even still going.
Very interesting. 2N3055 single ended output stage for a preamp ?
If yes, probably similar sonic character than "ZEN"power amp versions from Nelson Pass.
Are there schematics ?
Probably the first datasheets was published 1964 in this data book from RCA:
http://www.introni.it/pdf/RCA Transistor Manual 1964.pdf
I suspect that announcements, advertisements and brochures about this product with its special features were to be found shortly beforehand in a large-scale advertising campaign in various magazines for industrial electronics from those days.
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If it’s in a preamp it’s probably the voltage regulator - what the 2N3055 was originally DESIGNED for.
No, it's the main amplifying transitor in this design, together with a lot of matched BC 184's.
Powersupply is seperate, 24 V DC.
Willem.
Powersupply is seperate, 24 V DC.
Willem.