I have receive this sites from the RCA handbook 1981 - thank you therefore. There are not to find online e. g. by datasheetarchive and alldatasheet. Please let me know the exactly title of this book.
by post #33 and #34 about
http://www.diyaudio.com/forums/parts/167680-vintage-transistors-4.html
you will find cover images from various other RCA databooks.
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When the output swings near the rails the Voltage across the transistors will approach 110 Volts on a 60 Volt device.
I once mistakenly put an RCA 40411 into a Phase Linear 400. The 40411 was rated 90 Volts and the Phase was 160 (+/- 80 rails). Amazingly it did not blow up before I discovered my error.
Also there are times when the line voltage is high which makes the margin even worse. Stay within the 'absolute maximum' values in he data sheets.
G²
In those days each year RCA release a new edition of that databooks.
in the attachement two examples.
sometimes about
power | eBay
there are such vintage data books.
The question is, in which year the 2N3055 first time mentioned.
Is there any brand name or model number of this device available?
Attachments
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Well let us see the design has THREE pairs not one. It runs from 55 volts and has 2 Vbe drops so the maximum output voltage is under 38 volts RMS. However the maximum RMS voltage that will not blow up the 60 volt power transistors is 20 volts! The maximum current has already been discussed.
Do you know what power is? 20 x 20 / 8 = 50!
Collector−Emitter Voltage VCEO 60 Vdc From the ON Semi data sheet! +/- 45 = 90 volts above what a 2N3055 is rated!
I think, there are various missprints in the schematic from the first post here.
go to post #79 about
http://www.diyaudio.com/forums/soli...odels-quasi-complementary-power-output-8.html
there you will find a topology for higher voltage use of low Uce BjT devices. I assume, basiclly the same topology is used in the amp from post #1.
Mr. Nelson Pass uses also such topology by the Threshold 800A and 400A for using higher voltages:
go to post #12 and #14 about
http://www.diyaudio.com/forums/pass-labs/5426-800a-schematic.html
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Take a look at the data sheet for SOA or safe operating area. http://www.onsemi.com/pub_link/Collateral/2N3055-D.PDF
At 60 volts the safe current (under 1 amp) is not high enough to be useful!
I also have a copy of that RCA book in tiefbassuebertr's post in my posession. It dates back to 1981 (my student days) and all of a sudden it makes me feel very old.
There are two versions of the 2N3055 in it. The normal one (equivalents listed as 2N6569, BDX18, 2N6594 and MJ2955) and a Hometaxial (equivalents listed as 2N6253, 2N6254, 2N6371 and 40251) version, labelled as "formerly 2N3055H." Go figure.
There are two versions of the 2N3055 in it. The normal one (equivalents listed as 2N6569, BDX18, 2N6594 and MJ2955) and a Hometaxial (equivalents listed as 2N6253, 2N6254, 2N6371 and 40251) version, labelled as "formerly 2N3055H." Go figure.
go to the attachement by post #9 about
http://www.diyaudio.com/forums/solid-state/32694-simple-stereo-amp-aroud-2n3773-3.html
concerning the 2N6253, 2N6254, 2N6371, 2N3055H and 40251 there must be also such an overview from RCA and divided in families.
No, I don't stop this. My inane requests for literature - as you call this - is necessary to find out several important things.tief;
With all due respect, will you PLEASE stop littering every topic on diyaudio with your inane requests for literature ?? It is really irritating when I see the original topic get sidelined by your bleatings.
Not everything, that is important to know, is to find online.
supplement to post #69:
Another explanation could be, that the used main transformer is very small (low value of VA). Thus the voltage of +/-55 volts goes down already at low current flow through the load.
Hi everyone i was the one who put the original statement up about that the basic reason i started it was i have a surplus of 2n3055 transistor in my junkbox allready mounted in heatsinks. Now as these amps are not going to be hi fidelity all i wanted was the best way of using these transistor for maximum power. I don't mind if its Class B or Class A B or Complimentary symetry or quasi whatever i just wanted the best design i could find to deliver the most power the only schematic i could find otherwise that could possibly deliver 150 watts is this one i found made by Sunn which in the sixties was a off spin of Fender as far as i understand (correct me if iam wrong) but the problem being that it fed the output transistors with a transistors which in a sense is a better way of doing it keeps them isolated but where the hell you would work out the specs of the transformer and then get it wound or diy i really don't know. So if anyone has a schematic that i could use to get maximum power out of these transistors to at least use them up i would love to hear from them. Ultimately i would like to use them up rather than decorate the shed with them. Thanks
View attachment sunnconcertbass.pdf
from doing my homework or maths i should say on that first schematic i posted yes when that amp is run at full power the off transistor would see the full rail voltage. the rail voltage as far as i can see would have to be around 40 volts so 80/2.828 then square the answer which is 800.24 then divide that by the speaker impedance so 4 ohms and that comes to 200 watts if you do the same calculation and divide 800.24 by 8 ohms you get 100 watts. Now thats my calculations on how i got that result i welcome anyone to show me where i have gone wrong. Cause we can all learn from each other.
I think everyone around here would rather you decorate the shed and the Christmas tree with them, and go spend money on new C5200's or 21194's to build amps. But we see the reason why people occasionally post on here about building with 3055's - because they ALREADY HAVE THEM. I played with this about 2 years ago, but other things like building a new shop got in the way. If you want something bigger than a NAD3020, start with something like in post #30. It should work. Whether it's possible to convert to quasi-comp is still unknown, but what would it hurt to try? You have nothing to lose but a few small signal transistors and a few (dozen, hundred, etc.) otherwise useless 2N3055's.
This is a reasonable request, but you need to tell us exactly what type of 2N3055 you have there and how many. Are they the H version? How big are the heatsinks?
The obvious answer is to build something like the HK Citation 12, but with lower supply voltages if you do not have the H version or do not screen your parts to be sure that they will take 90V or so. The obvious way to get more power is to build two on the lower supply voltage and bridge them, however you'll probably want to double up on the output devices if you do this.
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At 40 volts rails into 4 ohms the peak current would be 10 amps into a resistor. (This ignores the 4 volt drop the data sheet has for this transistor.) The drive current in the schematic is .05 amps that goes into the first 2N3055 that then drives the others. The gain of the first transistor would be around 20 that would give you 1 amp to drive the output devices. Their gain at high current would be around 5 so that would only give you half of the current required to drive a resistor. so 5 x 5 / 2.828 x 4 = 35 watts! So the actual power would be determined by the actual transistor characteristics as you are ignoring the guaranteed minimum values. Of course a 4 ohm loudspeaker is not a resistor,
Of course the next issue is if all of your 2N3055 are actually the same. Otherwise they will not share the current and one will burn out.
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