[sdiy] hi hFE transistors indicated for "muting" purposes used as high gain amps?

[anthony]

I always wondered what separated the tansistor with a high hFE (800+) 
specified on datasheets for use in audio muting applications from other 
transistors with a high hFE. And of course I always forget if I am talking 
about hfe or hFE...

Oh I see by checking the datasheet for a 2SC3622, for example, it is the 
high DC current gain or hFE.

So I wouldn't really want to use these for, say a low noise, small signal, 
high gain preamp?

Of course I have some 2SC1222's and some 2SC900's and 2SC1000BL's that would 
fit the bill for that

Most of my parts I get from gear that I cannibalize. I make note of the 
quality of the piece and it gives me an idea what to expect from the parts. 
And though you'd never guess that you can get premium-ish parts from a JC 
Penny branded stereo, you can...

I like it when I luck upon some 2SA798 matched duals and their NPN 
counterpart that I can never remember...

So I guess I'm answering my own question.

Of course you can't judge a transistor for preamp applications based on high 
hfe alone. 2SC828's & 2SC373's do just fine with hfe's of 200-300.

What usually brings up this line of thinking is substituting parts specified 
in a certain project. For instance, I have VERY few BC550C's or 2N5087's or 
2N5088's. So I have to come up with a good, usually Japanese substitute. 
I've gotten pretty good at figuring out which ones would work where, but the 
"muting" transistor puzzled me. I guess if I'd just paid attention to the 
point being it's high DC current gain and not small signal gain.

Also it occurs to me that a lot of datasheets that specify a transistor as 
"low noise" are actually fairly deprecated. It would be good to hear from 
anyone with good luck with low noise transistors of relatively recent 
manfacture, like 2SC3199 (or is it the 2SC3189 or is it both?) and, the 
2SC2458(L), etc...


Cheers,
Anthony