The German Physiks Emperor Extreme stereo power amplifier uses a large toroidal power transformer and generously rated reservoir capacitors to deliver 600W RMS into 4 ohms with both channels driven.
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The heart of an amplifier is the power supply, so great care was taken with the design to ensure that it would be able to provide the audio sections with a source of power that was as stable and noise free as possible. The low level signal section, power amplifier stage and control section all have their own independent toroidal power transformers. These were chosen for their low external magnetic fields. To minimise the effects of stray magnetic fields, all three transformers are housed in their own screened enclosures.
The amplifier’s incoming mains power is not routed through the power switch, as these can have a detrimental effect on the sound, more so with power amplifiers. Instead, this switch supplies power to the standby circuit and when the front panel On button is pressed, this turns on a high current relay which carries the mains power. When a large power supply is connected to the mains supply, the initial in-rush current can be high enough to trip circuit breakers or blow fuses.
To prevent this, a 4-stage soft start circuit allows the power supply to “slowly†charge before it is switched out of the circuit. This also reduces the stress on the power relay. High quality power supply capacitors are used with additional decoupling capacitors located physically as close as possible to where they are needed in the circuit. Great care was also taken with the internal grounding to prevent the introduction of noise.
Premium grade WBT loudspeaker terminals provide a reliable and high quality connection and are also easy to secure and release. A ground lift control allows the signal ground to be disconnected, which can be helpful in reducing mains hum caused by earth loops. This may be operated using the remote control that is supplied with the preamplifier. Great attention was also paid to the aesthetics and the mechanical construction. High voltage power supply rails for the low level signal stages and a balanced output stage ensure a very wide dynamic range. ■
