Our first headphone amplifier is a new and ground-breaking development in which the analogue amplifier section, the converter section and also the case mechanics operate to perfection. The analogue section of the HA 200 is based on the unique T+A HV technology. Its high-performance output stages operate in Class-A mode with a high idle current, and are effortlessly capable of driving even the most difficult of headphones. The impedance of the three headphone outputs can even be matched to the headphones in use and the individual sound ideas. A crossfeed function for creating a sound stage image positioned in front of the head is available on request. The high-quality mains sections – one digital, one analogue with two separate torroidal transformers- provide very generous reserves of power.
The digital section is fitted with the proprietary T+A True 1-Bit digital / analogue converter, which provides an incredible DSD 1024 for Bitstream, and the T+A quadruple converter with 32 Bit / 768 kHz for PCM. Like all current T+A DACs the new HA 200 also features a sophisticated and completely separate decoder architecture for DSD and PCM, ensuring that all digital formats are decoded to the finest standards.
The design and materials of the case harmonize perfectly with the unique electronics. The HA 200 is significantly larger and heavier than other headphone amplifiers, but this is not surprising given the more than 2300 components and the sophisticated HV technology. All the case components are produced from non-magnetic aluminium, and the front panel is machined from solid plate material – just like the HV series. Accurate QPPM metering instruments and a large screen supply important system information, and provide an accurate indication of operating conditions. The FM8 IR remote control controls all functions of the HA 200. We have designed the HA 200 in every respect with no hint of compromise and without regard to cost, for we had only one goal in mind: musical reproduction to the very highest standard of perfection.
Amplifier Section
The amplifier section has an absolutely crucial part to play in the overall design. And that’s why we decided to adopt the principles of our HV series: pure analogue Class-A design with special MOS-FET transistors, no op-amps, no chips and a separate 100-Watt analogue mains section. Even the crossfeed function is generated by an analog filter circuit. The XLR and Cinch inputs take the same form as in the HV series, and the pre-amplifier is designed in such a way that it feeds the output stage in the optimum manner. Gas-tight encapsulated gold contact relays take over the volume control and adjustable loudness function and bridge the tone control completely (flat) on request, they are absolutely free of distortion and noise. Even after many years of operation these components are not subject to contact problems due to corrosion, dust or ageing effects. The relays are integrated directly into the circuit design, keeping the signal paths as short as possible.
Since we had decided to cater for different headphone types, the output stage needed to be extremely sophisticated. Normal loudspeakers have impedances in the range 2 to 10 Ohm, which is not critical. However, headphones may have impedances in the range 10 to 1000 Ohm, and this certainly presents a challenge. Low-impedance types draw high currents, whereas the currents flowing in high-impedance types are relatively low; however, the voltage must be very stable. We overcame this problem by designing the output stage of the HA 200 to be capable of effortlessly delivering relatively high currents, while the mains section transformers (2 x 50-Watt) are extremely stable and constant.
