Mosfet Hi-Fi Power Amplifier

14 EE February 1989 MOSFET HI-FI POWER AMPLIFIER A quality 160-watt hi-fi output amplifier based on the Siemens BUZ series MOSFETs. Until not so long ago, the BUZ series of MOSFETs from Siemens were hard to come by and very expensive. That was a pity, because these devices offer a very good specification. Fortunately, the situ- ation has improved considerably, although the transistors are still only available as n-p-n types. However, n-p-n types can be used just as well as com- plementary pairs as the present circuit proves. A power amplifier, whether it uses bipolar devices or MOSFETs, needs a drive circuit. When MOSFETs are used, that circuit can be kept pretty straight- forward. This means that any modifi- cations in respect of power handling, bandwidth and distortion may be brought in fairly easily. The device chosen for the present circuit is recommended by Siemens for use as a power opamps in control engineering, which indicates that it is a very stable component. None the l...