Biasing values for transistors---n00b question

[rockgardenlove]

So I'm wanting to add another transistor to Joe Davisson's Easy Drive to make it a bit louder.



I was thinking of just taking the output(collector) of Q1 and sending it to the base of another transistor, etc. and output from the Q2 collector.  This would work right?  The only issue is, how should I bias the second transistor?  And how do I figure out how to bias things on my own?

Thanks!

[BrianJ]

You might try the same circuit again, without the diodes, 22uf cap, and .01uf cap, after the one you have built.  You would probably want to attenuate the signal between the two stages (volume control?) so you don't clip the second transistor.

That's easiest thing I can think of.

[R.G.]

And how do I figure out how to bias things on my own?

I must have typed in polemics on biasing a dozen times here.

Search for "R.G." and "biasing".

[cd]

And how do I figure out how to bias things on my own?

I must have typed in polemics on biasing a dozen times here.

Search for "R.G." and "biasing".

Or Google, type in "transistor biasing" (no quotes) the first ten or so links are very informative.  IIRC one has a Java or Flash applet that lets you play around with things.

[brett]

Hi.
The output of this is reasonably high.  Ther 2N5089 going flat out has plenty of oomph, but with 2 Si diodes the output is clipped to about 1.4 V p-p.  So try 6 diodes instead.  4 in one direction and 2 in the other.  (or 3 red LEDs) That'll give you about as much output as you can reasonably get.
cheers