Topaz 211C stereo amplifier
Specifications
TUBE COMPLEMENT: (4)
1 octal base 6SN7WGTA dual triode NOS
1 octal base 6BX7GT dual triode NOS
2 4 pin base 211 VT-4C large triode [ VALVE ART ]
1ST & 2ND STAGE
The large octal based triodes have lower microphonics and improved resolution over their smaller 9-pin counter parts. Our exclusive use of exceptionally large value Solen polypropylene coupling capacitors was implemented to improve the low frequency response.
OUTPUT STAGE
Single ended and self-biased the 211’s drive the refined double C core Bartolucci transformers with an improved low frequency response and theoretically lower distortion. Individual selection of speaker load impedance (4 + 8 Ohm) is accomplished via dual contact high current switches. (40 ampere rating)
ALL STAGES
Operate in class "A1" single ended. Self-biased...no adjustments (tweeks can swap valves without consequence) < ZERO FEEDBACK > No LOCAL or GLOBAL FEEDBACK of any kind!
POWER SUPPLIES:
- Dual output winding toroidal power transformer for 211 filaments is full wave rectified and DC filtered separately for each channel providing superior performance without the need for elaborate test equipment to balance out AC ripple and modulation effects which normally occurs when using AC current!
- Separate power transformers and filters provide total isolation between the INPUT and OUTPUT stages. The INPUT High Voltage power supply (+450V) uses a double Π L.C. filter network to obtain complete immunity from power supply induced signal aberrations. The 1st stage is further isolated from the 2nd stage using an RC filter network. Two power transformers are used in the output power supply to further reduce mechanical vibration. The OUTPUT High Voltage power supply (+1200V) uses a current surge limiter and a dual full wave rectifier configuration feeding a double Π L.C. filter network for excellent regulation as well as superb ripple and noise rejection!
- Four large chokes and seven polypropylene capacitors [ 3 are oil filled ] are used in the two high voltage power supplies which makes this a " PURIST POWER SOURCE " of the highest caliber!
MECHANICAL CONSTRUCTION:
- Extremely rugged (12 gauge) all welded steel chassis was implemented to further reduce any possibility of vibration induced signal aberrations.
- 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.
- Tubes are left uncovered to enhance the visual arts.
CIRCUIT BOARDS :
PCB's using precision double turret terminal posts
Our fixed terminal hand crafted printed circuit boards are a new technology used in construction and is a first in the industry. Again Wyetech Labs is at the forefront and is always looking for ways to improve reliability and construction.
Much of the components are mounted on double turret terminal post, especially the power resistors, which improve the heat flow. These boards are then held elevated from the surrounding metal chassis to avoid any capacitive coupling between components.
The double turret terminal post are first swaged to the printed circuit board and soldered into place. After that the boards are then hand assembled with most parts soldered to these terminal post using silver based solder. For wiring to and from the boards Weco screw down terminal connectors are used to make connections between the various components and to facilitate easier replacement of parts for future reparability and long service life. This technique will result in much faster trouble shooting and repair in the event of any failure requiring servicing.
AUTO-SEQUENCING:
Power on cycle completes in 60 seconds
- Three time-delay relays provide proper power sequencing for stabilized circuitry before use and to provide extended tube life.
- STANDBY SEQUENCE 1: Allows filaments to reach operating temperature before applying high voltage. Can also be invoked manually via the POWER SWITCH.
- POWER SEQUENCE 2: Applies high voltage to input stages and allows circuit elements to stabilize before next sequence.(red LED lights)
- POWER SEQUENCE 3: Applies high voltage to output stage. (Green LED lights--red LED turns off)
- POWER SEQUENCE 4; A few seconds later the auto-mute is disengaged completing the turn-on sequence.
POWER SWITCH SETTINGS:
- TOP - ON ( auto-sequencing )
- MIDDLE - OFF
- BOTTOM - STANDBY ( sequence 1 only )
FREQUENCY RESPONSE :
+/- 1 dB .... 16 Hz to 22 KHz
| INPUT IMPEDANCE: | 100K OHMS |
|---|---|
| ABSOLUTE PHASE: | non-inverting |
| GAIN: | 27db (0.55VRMS maximum for full output) |
| POWER OUTPUT: | 18 Watts RMS |
| NOISE & DISTORTION: | below audibility |
| STAGE WIDTH: | wide open |
| STAGE DEPTH: | exceptional layering |
| PERCEIVED SOUND FIELD: | precise imaging |
| CLARITY: | crystal clear |
| POWER CONSUMPTION: | 300 Watts continuous |
WEIGHT:
| NET: | 102 LBS (46 KG) |
|---|---|
| SHIPPING: | 125 LBS (57 KG) |
| DIMENSIONS: | 16” W x 22”L x 10”H |
|---|
LIMITED WARRANTY:
| TUBES | 1 YEAR PARTS |
|---|---|
| COMPONENTS | 10 YEARS PARTS & LABOR |