This is Simple video amplifier circuit using LM359. That use a op-amp IC number: LM395 or similar, which can work in high frequency such as LM3900 series [...]
These are many pre tone control circuit, use transistors as main. so low noise,good sound, cheap and easy to buy parts, you can builds with PCB layouts
This is Simple preamplifier circuit using transistors,low noise and easy to builds we have many circuit below, simple to difference projects [...]
This is a 4 transistor audio amplifier circuit. Which is a 4-transistors complementary push-pull amplifier, that shows the basics of audio amplifier design.