High Power Class A Mono Design Incorporates Sony VFET Output Stage
LAS VEGAS, Jan. 7, 2014 – At a special press briefing held during the 2014 International CES, Sony Electronics joined with Pass Laboratories to demonstrate a unique high powered (250 watts output into 4 ohms) Class A amplifier which incorporates hand-selected Sony Vertical Field Effect Transistor (VFET) output devices.
This special model was developed specifically to commemorate the 40th Anniversary of VFET technology, which was utilized by Sony and a handful of other companies in a limited series of amplifiers in the late 1970s.
According to Nelson Pass, founder and president of Pass Laboratories, “These historic amplifiers are now prized for their exceptional sound, which is a credit to their extraordinary linearity of their VFET devices. As a result, they established a benchmark for the next generation of solid state amplifiers which followed, that have become the reference standard in high quality music reproduction today”.
“Triode-like” Sound Quality
Sony’s VFET devices, also known as Static Induction Transistors (SIT), were smaller, less costly and much more efficient than conventional vacuum tube designs and were widely acknowledged for their “Triode-like” sound quality. Additionally, these transistors serve as extremely fast switching devices, which enabled Sony to introduce the first high-powered Class D audio amplifier in 1976.
This exclusive Pass Laboratories commemorative amplifier employs complementary matched pairs (2SK82 and 2SJ28) of Sony VFETs, which were in storage for nearly 40 years. The mono block amp operates in Class A mode, with a balanced circuit from input to output and no feedback required. The amplifier also includes a highly regulated stable power supply, which enables it to achieve 250 watts peak power into a 4 ohm load, with relatively low distortion (less than 2%).
In developing this product, Pass Laboratories utilized Sony’s highly acclaimed AR-1 reference loudspeaker, which proved to be an ideal match for the amplifier’s overall performance.
To celebrate this remarkable achievement, Sony Electronics will join with Pass Laboratories following CES in sponsoring a select number of demonstrations of this amplifier at Sony and Pass authorized dealers located throughout the U.S.