Preamplifier circuit diagram:

This is the Preamplifier circuit diagram for the amplifier. Every amplifier needs a bass tone control circuit. and also a pre-amplifier. This is a mono circuit. For stereo needs a dual circuit. This circuit runs with 12 volts. This circuit can control bass and tone. Here are 3 volumes. one for volume, one for the bass, and another one for the tone.

How to add an extra transistor:

How to add an extra transistor? A Maximum transistor amplifier can add extra transistors, but it will not work if we don’t increase the amperes or voltage. If we want to add an extra transistor, then we have to increase the voltage and amperes. like the voltage is 35-0-35 and 3 amperes for 2 transistors. If we add an extra 4 transistors, then we have to add an extra 4 amperes. And the voltage can be 45-0-45 maximum.