For your consideration.
Excellent condition, 7 month old, AT6005 amplifier.
Beyond Kessler’s personal identification, these amplifiers are new in more significant ways.
1. As in Kessler’s previous top-of-the-line designs, these amplifiers
are fully balanced, differential amps, but unlike his earlier balanced
designs which were essentially balanced bridged amplifiers, the 6000
series uses only a single input stage with dual-differential output
stages. The reason: the advantages of balanced designs are retained
and noise is reduced by 50%.
2. The design uses current feedback instead of the more common
voltage feedback. The reason: current feedback amplifiers are faster
with virtually unlimited slew rate and are better able to reproduce
today’s best music and film sound.
3. Kessler used Thermaltrak output devices for the 6000 series.
Unlike traditional designs where external diodes or transistors attached
to the heat sinks track the amplifiers operating conditions and use the
details to adjust bias, Thermaltrak devices have the temperature
sensing device in the same package as the output transistor. The
results: bias is optimized in real-time.
4. The 6000 series use dual DC servos to track and maintain DC
offset. The result: DC in the amplifier’s output is reduced to
5. These amplifiers use a revised PCB layout. They are still
modular with the complete amplifier including the power supply parts on a
single card, but now the AC components are on one edge of the board and
away from the signal input. The result: improved signal-to-noise
6. All of the amplifiers in the series use dual toroidal
transformers, dual power switches and dual line cords. The results:
the AT6002 is now a complete dual-mono design and the amplifiers with
many channels, as in the 7-channel AT6007, can be hooked-up to two
independent 20 amp circuits for greater sustained output power than is
possible from a single AC circuit.
All the amplifiers in the 6000 series are rated at 300 Watts RMS from
20 Hz to 20 kHz with no more that 0.03% THD at 8 ohms with all channels
driven and 450 Watts RMS at 4 ohms under the same conditions.
Signal-to-noise ratio is typically 128 dB referenced to full output so
each amplifier in the series is capable of playing back the full dynamic
range available on today’s lossless recordings.
Sound and Vision review: http://www.soundandvision.com/content/ati-at6005-amplifier
Questions gladly answered.