Just close the two switches fast.
The first stage is a differential amp dealing with the AC gain, the second stage is again a differential amplifier dealing with the DC offset. The voltage gain is set at 11, so for a full output swing, you'd need a preamp for almost any signal source. The output stage is composed from two Sziklai pairs, which is very common for my topologies, as you may have noticed. Gives a little more headroom, and less distortion than a typical Darlington. Some of the specs are:
- Input Sensitivity - 1.76Vrms
- Output Power - 95W
- Drawn Power - 131.5W
- Efficiency - 72%
- THD+N - 0.01%
- Bandwidth - <1Hz to only limited by the 22pF cap, maybe around 100kHz
- Ripple rejection - very good, residual ripple almost immeasurable.
