Wyetech Labs Pearl Stereo Tube Linestage Preamplifier

[ 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..

FREQUENCY RESPONSE

[ reference to a sine wave at 3.5 Vrms output ]