Rega Osiris - Manuel (Page 7)

TECHNOLOGY BEHIND THE OSIRIS
Amplifier circuit.
The Osiris uses a fully symmetrical circuit throughout and a low distortion high linearity
and bandwidth common base voltage amplifier driver stage. This type of symmetrical
circuit topology will provide the necessary voltage swings to enable the Osiris to drive
any speaker system with the minimum of distortion. Eight Sanken 200 Watt output
transistors are used in a “triple” high current output stage enabling the Osiris to drive
even the most awkward of speaker systems with ease. The cascoded differential input
amplifier uses two low noise LED referenced current generators. The open & closed loop
feedback levels and gain bandwidth product components are optimised to give a tight and
controlled sound stage, especially at the low frequency end of the audio range. Nichicon
audio grade capacitors are used in bypass and decoupling positions. Electrolytic
capacitors have been bypassed with polyester capacitors where necessary improving on
the HF performance. Low inductance film SM power resistors are used in the output
stage. All these features amalgamate to create the supreme level of performance found
in the Osiris.
Power supply.
The Osiris uses two low noise purpose designed 400VA toroidal transformers using
high-grade fully bonded core material. The transformers are mounted to the chassis
using Rega’s innovative mounting technique, which eliminates noise being transferred
from the transformer to the case when the transformers are operating under arduous
mains (line) conditions with high levels of asymmetric mains (line) distortion. These
transformers combined with 40,000
µF of Rega K-Power smoothing capacitors per
channel, provide more than enough current to drive the hardest of loads. All the power
supplies utilise fast recovery rectifier diodes throughout. (Fast diodes generate less high
frequency switching noise therefore giving rise to a cleaner DC). The input and low-level
driver stages are fed from a regulated symmetrical tracking power supply with a low
noise voltage reference, which provides a fully stabilised low noise voltage, ensuring the
highest level of sonic purity. All the dedicated audio power supplies feed only the audio
circuits. The input switching, display & micro controller and protection circuits have their
own dedicated supplies, thus keeping the audio signal path as pure as possible.
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