Friday, June 13, 2014
Orpheus Heritage Power Amplifier
The Heritage power amplifier is the latest high-end amplifier from Orpheus.
Its internal topology is based on a complete dual mono architecture. The amplifier has several operating modes: stereo, mono and bi-amp.
The rated output power is of 2 x 250W in stereo and bi-amp mode. In mono mode the output power is of 1 x 1000W (on 8 Ohms).
Using two separated power supplies and amplifier boards in stereo and bi-amp mode, makes the two channels of the amplifier totally independent to minimize channel-to-channel crosstalk.
In mono mode all the cards are interconnected together in order to deliver the maximum power to the load. The different modes of the amplifier and its high power allow it to be used with a wide range of speakers.
The power amplifier uses a class AB output stage based on four hand matched pairs of mosfet power transistors per amplifier board. Mosfet transistors advantages are numerous compared to usual bipolar output stages. Lower ‘ON’ resistance and by the way that the power is identically distributed between the transistors makes them more efficient to transmit more power to the load rather than dissipating it as useless heat. Mosfet technology also has higher switching speed resulting in a faster, sharper and more accurate response compared to bipolar systems.
The output stage is biased with a voltage to set the operating point of the power transistors to get extremely low THD and exceptional audio performances (THD of 0.01% for 200W on a 8Ω load in stereo and bi-amp mode).Thermal compensation of the output stage has been also developed in order avoid overheating of the transistors when they are strongly solicited. Several internal protections are constantly monitored like the instantaneous power consumption, power supplies voltages and currents and heatsink temperatures of the amplifier.
The two low-noise power transformers are able to provide a total amount of power of 2000VA to the amplifier when used in mono mode. The total capacitance of the power supplies in mono mode is more than 180mF. The oversized power supplies guarantees the unit to provide large peak currents and stable voltages even when delivering high output power.
Heatsinks have been cleverly integrated into the device to optimize heat dissipation assuring perfect operating conditions. Its outstanding specifications, imposing size and weight (50kg) followed by refined and stylish curves makes this anodized aluminum piece of art remarkably stand apart from conventional amplifier.