TOPAZ 572B STEREO AMPLIFIER
SPECIFICATIONS
TUBE COMPLEMENT
| 1 | octal base 6SN7WGTA | dual triode |
| 1 | octal base 6BX7GT | dual triode |
| 2 | SV-572-10 SVETLANA | large triode rated for 125 watts plate dissipation |
CIRCUIT DESCRIPTION
All stages operate in class "A1" single ended and contain automatic self-biasing circuitry. Our exclusive use of exceptionally large value Solen polypropylene coupling capacitors is one of the reasons for our extended low frequency response. Each Svetlana directly heated triode ( DHT ) drives its own exquisitely refined Audio Note output transformer to get 23 watts RMS per channel in pure CLASS A1 operation. The output transformer windings from each channel can be switched via dual contact high current switches to allow the selection of speakers rated for 4 or 8 Ohms. WE EMPLOY NO FEEDBACK of any kind due to the low distortion ultra-linear amplification stages employed in our design.
POWER SUPPLIES
- Dual output toroidal power transformer for 572-10 filaments provide a filtered DC separate power supply to each output triode eliminating the typical AC balance adjustment while providing superior performance.
- Separate power transformers and filters for the two high voltage power supplies provide total isolation between the INPUT and OUTPUT stages. These filters enable complete immunity from the AC power line.
- Polypropelene in oil capacitors have doubled the storage capacitance from that used in the 211A model.
- A total of six heavy chokes and seven large polypropelene capacitors are used in the power supplies.
- Complete elimination of electrolytic capacitors in the High voltage power supplies.
MECHANICAL CONSTRUCTION
- Extremely rugged (12 gauge) all welded steel chassis was implemented to further reduce any possibility of vibration induced signal aberrations.
- Highly polished showcase chrome and black nickel plating on brass accentuates the chassis styling.
- Very high quality pearl enamel baked on finish to further enhance the artistry.
- Rugged solid brass handles with nickel finish are implemented for ease of handling.
- A fine mesh screen covers the high voltage transformers and chokes.
CIRCUIT BOARDS
(Hand crafted Vectorboards using precision double turret terminal posts)
The components are mounted on Vector boards which contain swaged terminal post. These posts are divided into two areas. The wiring used is laid out on both top and bottom of the board and is soldered to the bottom layer of the terminal post. This point to point wiring allows the highest possible component density while maintaining the shortest possible SIGNAL PATH! The components are then soldered into place on the top layer of the terminal which allows the replacement of any part without removing the circuit board. High quality Teflon coated Silver plated OFHC copper wiring is used where appropriate and silver solder is used throughout.
AUTO-SEQUENCING
(60 second power on cycle)
Three time-delay relays provide extended tube life and proper power sequencing for stabilized circuitry.
| POWER SWITCH SETTINGS | A 3 position toggle switch provides ON, OFF and STANDBY functions |
| IMPEDANCE MATCHING | Two high current toggle switches enable setting for 4 or 8 ohm speakers |
| FREQUENCY RESPONSE | +/- 0 dB > 100 Hz to 10 kHz -1 dB > 20 Hz to 25 kHz -3 dB > 16 Hz to 37 kHz |
| INPUT IMPEDANCE | 200 kW |
| ABSOLUTE PHASE | non-inverting |
| GAIN | 25 db (0.75V RMS maximum for full output) |
| DYNAMIC HEADROOM | 4 db (short duration music peaks of up to 90 watts for extended dynamic headroom) |
| POWER OUTPUT | 23 watts RMS per channel |
| POWER CONSUMPTION | 375 watts |
| WEIGHT | NET: | 102 lbs ( 46 kg ) |
| SHIPPING: | 117 lbs (53 kg) |
| DIMENSIONS | 16" W x 22" L x 10" H | |
| LIMITED WARRANTY | TUBES | 1 YEAR PARTS |
| COMPONENTS | 3 YEARS PARTS & LABOR | |
| EXTENDED WARRANTY | COMPONENTS ONLY | 20 YEARS PARTS & LABOR (See warranty registration) |
LIMITED EDITION
Each unit comes with a gold plated brass nameplate individually engraved with its own unique serial number.