Re: transistors in amplifier ear

ajholme_at_hotmail.com
Date: 07/11/04 

Date: 11 Jul 2004 03:13:59 -0700

pil wrote:
> 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

The oriignal parts list states:
Q1,Q2,Q3,_____BC547 45V 100mA NPN Transistors
Q4____________BC337 45V 800mA NPN Transistor

They recommend a heftier transistor for the output stage.

Your available transistors are:
2N2222 NPN 40V 800mA
2N3904 NPN 40V 200mA
BC309 PNP 80V 1A
BC258 PNP 80V 1A

So, unless you want to re-design the output stage (i.e. turn it upside
down and use a PNP transistor) I would try:
Q1,Q2,Q3 2N3904
Q4 2N2222

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