NEW MORRIS KESSLER SIGNATURE ATI AT-6000 SERIES AMPLIFIERS
Product Description
Advanced Limited Edition amplifier designed by Morris Kessler. The “Signature Series” designation with a facsimile of Kessler’s signature on the main panel acknowledges the special nature of these designs.
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 unlmited slew rate and are better able to reproduce today’s best music and film.
3. Kessler used Thermaltrak output devices for the 6000 series. Unlike traditional designs where external diodes attached to the heat sinks track the amplifiers operating conditions and use the details to adjust bias, Thermaltrak devices have the temperature sensor in the same package as the transistors. 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 insignificant levels.
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 performance.
6. All of the amplifiers in the series use dual toroidal transformers, dual power switches and dual line cords.
7. Additional channels (up to 7 maximum) may be added at a later date should ones needs change. Transformers: Dual Toroidal MOH type. Each transformer has an independent secondary winding for each amplifier channel. Electrically this is the same as a separate transformer for each channel. Power supply: Each module is a complete amplifier channel including power supply rectification and 59,400 microfarads of capacitance. Output Devices: High-current bi-polar and ThermalTrak devices with active bias for real-time optimization regardless of operating temperature or duty cycle. Circuit Boards: Double-sided, FR-4 glass-epoxy, "Mil Spec" boards. Assembled in-house. Protection Circuits: Complete, over-temp, over-current and DC protection without any current limiting. There are no fuses or relays in the active audio path. All protection is optically coupled with full automatic reset. Remote Trigger: Activated from 3.3VDC to 24 VDC via a heavy-duty relay Soft Start Circuitry: Ultra soft turn on reduces in-rush current to a minimum. Multiple units can be turned on without tripping circuit breakers eliminating the need for sequencing. Complete turn-on takes approximately 45 seconds. Power Cord: Dual, detachable, 3-wire IEC 15-amp cords. Warranty 90-days parts and labor extendable to 7-years with product registration. Dimensions:
17 1/4" W X 9 1/2" H X 18 1/2" Handles protrude 1 3/4" from front panel. Please allow 1 1/4" to rear for I/O jacks. Weight: Unit weight is 85 lbs. Shipping weight is 110 lbs
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 unlmited slew rate and are better able to reproduce today’s best music and film.
3. Kessler used Thermaltrak output devices for the 6000 series. Unlike traditional designs where external diodes attached to the heat sinks track the amplifiers operating conditions and use the details to adjust bias, Thermaltrak devices have the temperature sensor in the same package as the transistors. 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 insignificant levels.
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 performance.
6. All of the amplifiers in the series use dual toroidal transformers, dual power switches and dual line cords.
7. Additional channels (up to 7 maximum) may be added at a later date should ones needs change. Transformers: Dual Toroidal MOH type. Each transformer has an independent secondary winding for each amplifier channel. Electrically this is the same as a separate transformer for each channel. Power supply: Each module is a complete amplifier channel including power supply rectification and 59,400 microfarads of capacitance. Output Devices: High-current bi-polar and ThermalTrak devices with active bias for real-time optimization regardless of operating temperature or duty cycle. Circuit Boards: Double-sided, FR-4 glass-epoxy, "Mil Spec" boards. Assembled in-house. Protection Circuits: Complete, over-temp, over-current and DC protection without any current limiting. There are no fuses or relays in the active audio path. All protection is optically coupled with full automatic reset. Remote Trigger: Activated from 3.3VDC to 24 VDC via a heavy-duty relay Soft Start Circuitry: Ultra soft turn on reduces in-rush current to a minimum. Multiple units can be turned on without tripping circuit breakers eliminating the need for sequencing. Complete turn-on takes approximately 45 seconds. Power Cord: Dual, detachable, 3-wire IEC 15-amp cords. Warranty 90-days parts and labor extendable to 7-years with product registration. Dimensions:
17 1/4" W X 9 1/2" H X 18 1/2" Handles protrude 1 3/4" from front panel. Please allow 1 1/4" to rear for I/O jacks. Weight: Unit weight is 85 lbs. Shipping weight is 110 lbs
