|The X150 stereo amplifier embodies the design technology and
refinements of the larger "X" series amplifiers including the patented
The Supersymmetry circuit topology improves the
performance of a balanced amplifier by precisely matching the characteristics of the two
balanced halves. To the extent that distortion and noise can be made identical on the two
output connections, they will not be seen at the balanced output. Ordinary matching
techniques can achieve improvements by a factor of 10 or so under the best conditions, but
the Supersymmetric technique lowers distortion and noise by another order of magnitude.
The amplifier uses ultra matched components in a simple balanced Class A circuit. It
contains only two gain stages: a balanced single-ended Class A voltage stage driving a
bank of 20 high power Mosfets operated as followers. The X150 accepts both single-ended
and balanced inputs and is fully DC coupled with no capacitors in the signal path.
The X150 is rated at 150 watts per channel in 8 ohms and 300 watts into 4 ohms. The
output stage is biased at an idle dissipation of 100 watts per channel, operating Class A
to 50 watts and Class AB at higher power levels.
The power supply features a high current toroidal transformer driving dual mono
secondary output stage supplies. Four 31,000 uF computer grade storage capacitors reduce
power supply ripple to about 1/10 volt. The front end circuitry is powered by a separate
secondary system with an additional 30 volts DC to drive the output stage "rail to
rail" without distortion.
The appearance of the X150 is similar to the larger amplifiers in the series. The face
plate is machined from thick aluminum stock and then anodized machine gray. The handles
are exactly the same extrusion as utilized on the larger amplifiers. The main power switch
is located on the rear of the amplifier and a convenient standby switch is located on the
front panel. Convenient front panel LEDs indicate the status of the amplifier. The input,
output, and AC connector are located on the rear of the amplifier. Single-ended inputs are
via RCA connector and balanced inputs are via XLR connector. Heavy duty five-way binding
posts are provided for the speaker outputs.
The amplifier is 19" wide, 7" high, and 22" deep front handle to rear
handle. The X150 weighs approximately 90 pounds in the shipping carton.