Which BC108 for a silicon Fuzz Face?

[Fancy Lime]

I picked up some BC109C's to try out. Smallbear didn't have any 108s when I ordered so I went with the next thing on the list that could be used in place of them.

The BC109C is identical with the BC108C except for the noise specs. The 109 has a lower maximum noise figure. So there is really no reason to try and find a BC108C if you can have a BC109C. However, if you want a lower gain variant, it seems like most manufacturers never made a BC109A, while BC108As are quite common.

Andy

[j-pee]

Lower gain device should be Q1 - so use a plain (no suffix) 108 for Q1, followed by a 108A or 108B for Q2.

as to "no suffix" / "ungraded" 108... (or 109)
I've just read that they are usually higher in HFE than "C" versions...
but measuring it helps either way

You're a little late...

being a little late if you take this forum as a real time conversation, sure... 12-13 years is quite a lag...

but why did I bump into this thread in the first place? cause I was seeking info... which I found here...
which means that this thread qualifies a valid source of info, so why not add to it?

ANYWAY:
as to the "no suffix" versions of these transistors,
I've just measured 12 pieces of BC109
and they were either around 300, in hFE, or 400...
whereas my BC109c stash has ones with hFE 500-550...

which means two conclusions:

the ungraded version can be LOWER in hfe, indeed, as said
the ungraded version produces a significant diversity, which means,
in 12 peaces you can find about 4-4 "pairs" or pair candidates

[j-pee]

I'd posted the above response twice (cause after posting it it looked like something had gone wrong) and I couldn't delete it ... hence this line here -- sorry

[j-pee]

as to "no suffix" / "ungraded" 108... (or 109)
I've just read that they are usually higher in HFE than "C" versions...
but measuring it helps either way

I don't think that is true and it's not what I've seen throughout my life.

My understanding is the uncategorized version is just chosen at random.  The datasheets show a wide range of possible hFE values.   The idea is they are cheaper.  In practice I didn't see much difference.   An interesting dilemma is how they could guarantee the part is in spec without measuring hFE, it is possible but with some risk attached.

this is absolutely my (lately gained) experience, too
what I posted was what I had just read
thanks for the clarification!