Wyetech Labs “Pearl” preamp in very good condition. Clear plexiglass top ... the way I received it ... no metal top in hand. No noticeable marks or scratches on paint (see photos). These limited, hand built products have very high-end parts and are well constructed - originally with a 10 year warranty that speaks to its durability. See Wyetech Labs review links for more information if interested. This Line stage offers a truly Memorizing and Engaging Listening Experience and is a Very well reviewed and well thought of piece........
- Machined aluminum plates [1/4” & 1/8” thick] bolted to square post are used to construct the preamp chassis. This provides excellent shielding from external radio frequency fields.
- Hard GOLD or BLACK NICKEL plated solid machined brass knobs for smooth operation of switches..
- Gold plated machined brass holder with 3M rubber feet inserts accentuates the styling and allows proper air flow for the vents under the chassis.
- The stepped Volume control has gold plated contacts with surface mounted 0.1% precision metal film resistors. [channel balance within +/- 0.05db]
- Balance control uses a sealed Electroswitch with silver plated contacts and 1% precision resistor networks.
- Selector and Tape Monitor switches now control relays located next to the RCA connectors
- Tape Monitor switch can also function as a processor loop
- OCTAL SOCKETS are hard wired to turret terminals which are then soldered to the PCB board making them easily replaceable. This insures many decades of operation while ensuring a lifetime of serviceability.
- Noiseless TOROIDAL power transformer and NKK rugged quality toggle switches
- Non magnetic stainless steel and brass hardware is used throughout.
- Automotive high gloss paint finish.
[ Hand crafted 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.
Most of the components are mounted on double turret terminal post. The OCTAL TUBE SOCKETS are also hard wired to these fixed terminals which in turn are soldered to the printed circuit board. This makes the tube sockets easily replaceable should the need ever arise. The muting relay and 555 timer chip are mounted in premium gold sockets which are soldered to the board for ease of replacement
The double sided printed circuit board [ PCB ] has been manufactured with the same high standards as that found in the Sapphire amplifier. It has full solder masking on both sides of it's premium glass epoxy board with white silk screening that identifies parts and there placement for fast efficient hand soldering and assembly. These boards are held elevated from the surrounding metal chassis to avoid any capacitive coupling between components.
We also use WECO screw terminal connectors to fasten wires to the PC board 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 a failure and thereby reduce the labor and cost of any necessary repair.
High quality Teflon coated silver plated OFHC copper wiring is used where appropriate to make connections to and from each board and silver solder is used throughout.
AUTOMATIC POWER SEQUENCING & MUTING:
To allow circuit stabilization and quite operation a 45 second automatic muting is activated during power up. Muting is accomplished using a 2-pole relay that shorts the preamp outputs. When disengaged the muting circuit is not in the signal path.
SELECTABLE GAIN CONTROL
Overall amplifier gain is controled by a toggle switch for each channel. It can be swirched between HIGH [ 13db (4.4x ] and LOW [ 5.5db ( 1.85x ] gain..
To change the gain settings, you must remove the top cover [ see page 2 for proceedure ] the analog board on the left contains the left and right channel switches to select high or low gain..
[ reference to a sine wave at 3.5 Vrms output ]1.+/- 0 dB FLAT ... 15 Hz to 200 kHz2.+0 dB/-1 dB ... 7 Hz to 520 kHz3.+0 dB/-3 dB ... 3 Hz to 950 kHz