It won't improve the circuit significantly.
- It will reduce the input impedance
- It will reduce the standing current in the stage and make it more difficult to predict
- There's no emitter degeneration so it won't increase the stability which makes it just an extra component
If you want to improve the circuit take the 100k to the junction of the pot and the collector instead of the positive rail, or introduce emitter degeneration which will almost certainly require that you make the 2 voltage divider resistors less than 100k.
w
For a simple circuit like this taking the input bias resistor to the collector circuit is best, as wakibaki suggests. It doesn't really matter whether you connect to the collector, or the variable resistor, or even the junction of the two diodes. Emitter degeneration would also help, but introduces complications which you may prefer to leave for later on.
Bear in mind that you won't get much output from such a low supply voltage.
Bear in mind that you won't get much output from such a low supply voltage.
Hello again, thanks for the replies. After adding an active tone stack i found that i had to remove the first transistor to get the amp working. I am now trying to finish this little amp now (i know its taken ages, i've been very busy) and i only have one speaker. Could i make 2 identical amps, bridge them and invert one by sending one channel into the inverting input of the preamps opamp and the other channel into the non inverting terminal of the other preamps opamp? Or is there a better method for this?
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