BC184C / BC214C replacements

[ruffrecords]

I'm not an expert in transistor but I'm building a 8 channel neve style preamp and on the BOM I also have bc184c as a transistor to use, but the guy that made the project told me to get a bc109c that was used on the early 1073. He also put a footprint on the PCB for a TO-13 transistor and not a TO-92 that why I was confused about it...
Any thought about this one?

In the early 1960s when transistors first became available in the UK, almost all of them were housed in metal cans. The BC109C was the very first go to low noise high gain NPN silicon transistor. Everyone in audio used it. Later on, the cheaper plastic TO92 packaged transistors came out and everyone switched to using BC184C instead. Not because it was any better, but because it was cheaper.

Cheers

Ian

 

[NOON]

I'm SURE I've seen some 184s in metal cans in recent days but I can't find them now. I did find some standard TO-92 ones with what looks like a Fairchild logo. I've run a couple with different date codes through the DCA75 and attached the Ic/Vce curves. When I get a few hours to spare I'll run some more and a bunch of different types from my collection, including some vintage germaniums, and upload the lot to a new thread. Let me know if there's any specific information you're after.

 

[NOON]

Maybe I was hallucinating the 184s in metal cans, I've been sorting huge piles of random transistors into proper storage containers lately and have been squinting at far too much fine print.

 

[Matt Syson]

Of course some of this has to be looked at from the perspective of when the various transistors (and op amps) were brought out. 'Low noise' was a comparative, comparing them to other devices available at that time. As has been alluded to, 'low noise' at what part of the current range you want it to work?
Transistors like the BC184 were also available in alternate pinout configurations L being a common orientation. C being higher Hfe specimens of whichever range. Previous transistors had green yellow or (blue?) spots on them to denote Hfe range. Of course knowing the expected bias voltages and the resistances around any given transistor it is easy enough to work out what the 'usual' collector current 'should' be. 'Kids these days don't know how lucky they are'. The early Op amps (709? which used asymmetric supply rails and would die if you shorted the output once you had persuaded it to stay stable in the first place. Scraping the paint off OC71 transistors to get a handy light sensitive transistor, or ensuring the earlier production versions were kept dark and cool if you want your circuit to work as you wanted. the happy hours spent comparing transistor specs in the Towers transistor selection guide.

 

[ruffrecords]

Ah, Matt. That brings back some fond memories. The very first transistors I bought were red spot ones. Onty 22/6 (£1.12.5 in decimal) and in those days my pocket money was £1 a month I rememeber when they started filling OC71s with an opaque goo which meant you could no longer scrape the pain off to make an opto-transistor.

Cheers

Ian

 

[Whoops]

Yes! Would love to see the Vce vs Ic for different base currents on the BC184C! And more than one would be great!

So I did the Vce vs Ic tracing on 6 different BC184C transistors, 3 of them are from Fairchild and 3 of them from TI.
Just to let you know that these are the possible tracing measurements on the DCA75:




here are the HFE of each of the BC184C transistors tested:
Fairchild 1: 732
Fairchild 2: 586
Fairchild 3: 686
TI 1: 592
TI 2: 537
TI 3: 578

____


FAIRCHILD 1


FAIRCHILD 2


FAIRCHILD 3


TI 1



TI 2



TI 3