Vectronics VEC-1680K - Manual (Page 16)

VEC-1680K Owner’s Manual Vacuum Tube Preamp
16
! ! Cut a 6” length of hook-up wire and attach it to tab #2. Solder.
! ! Thread the 6” and 4” leads through the mounting hole.
! ! Holding the switch so tab #1 is up toward you, firmly press the switch into
its mounting hole (it may take some pressure to collapse the plastic
retainers on each end) . The switch should snap into place and hold
securely.
! ! Connect the 4" wire from tab #1 of the switch to PWR on the PC board.
Solder.
! ! Thread the 6" wire through the power-jack mounting hole at the rear of
the chassis.
! ! Find the remaining red wire from the power transformer and thread that
through the power jack mounting hole.
Locate the 2.1mm power jack and position as shown in the pictorial diagram.
Note that there are three terminals. The terminal held in place by a rivet head is
attached to the center pin of the power connector. This is the (+) connection.
! ! Attach the 6" lead from the power switch to the (+) connection on the
power jack.
Find the terminal that exits the jack on the edge of the brown phenolic insulator.
This is the (-) connector, or ground.
! ! Cut a 4" length of hook-up wire and dress both ends.
! ! Connect one end to the (-) tab of the power jack without soldering.
! ! Connect the remaining red lead from the power transformer to the (-) tab
of the power jack and solder both leads in place.
Find the two (2) 2-56 screws and matching nuts.
! ! Install the power jack and secure it in place with 2-56 hardware.
! ! Connect the 4" lead from the (-) side of the power jack to GND on the PC
board and solder.
Locate the 12AX7 tube and remove it from its box. Note that the tube's 9 pins
are keyed to insert into the socket only one way. Turn the chassis over, find the
socket at V1 (through the hole in the top), and align the tube pins with the socket
holes.
! ! Carefully insert the 12AX7 tube into its socket (V1), taking care not to
bend or fold over any pins.