This is a HiFi pre-amplifier circuit diagram with low noise output. Very wide range frequency from about 10Hz until up to 100Khz will be gained by this preamplifier for maximum audio performance. This circuit uses BC550C / BC560C transistors as active component. Use regulated power supply 15VDC for maximum result.
Here the response of the preamp’s frequency and phase:
Here the diagram of total noise at output, measured with 600R load:
circuit by Graham Maynard