"Paul Burridge" wrote in message
news
On Sun, 11 Jul 2004 00:43:11 +0200, "pil" wrote:

BC 547
BC 337

"Norm Dresner" wrote in message
...
"pil" wrote in message
...
With what transistors can I substitute the ones in the amplifier ear?
http://www.electronics-lab.com/projects/audio/023/

I have the following available:

2N2222
2N3904
BC309
BC258

What was originally used?

Just use the 3904s all through (first substitute) or 2222s mebe. Ought
to do the trick, I'd have thought. Without thinking too deeply about
it, of course.
I stand to be corrected, as always.

2N3904's are fine for Vceo and Ft. Their Hfe(min) is also similar to the
two BC's, but falls short of the BC's max by a factor of 2. It's not all
that obvious from a quick glance why two different transistors were used in
the original but I'd certainly try 2N3904's in both places and see what
happens.

Norm