Jacks J1 and J2 have thread lengths too short to reach
through the 1/8” thick hardboard.
A simple solution is to use a flat tip 1/2” drill bit to
carefully remove enough material from the back of the
rear assembly to allow the threads to protrude sufficiently
out the front side.
After all the holes are drilled, peel off the graph paper
and clean the surfaces. This is a good time to apply a dark
walnut stain if you desire.
Cut two 7-1/4” lengths of square dowel, then use 12
brass wood screws to attach the front and rear assemblies
to the base. Use 1/8” pilot holes into the dowel to avoid
splitting it (see Figure 6). Mount all the components to the
assembled chassis except for audio module LN-1 and the
V1 socket. When satisfied with the fully assembled and
populated chassis, remove the front and rear assemblies
from the base.
Leave the base attached to the square dowels.
Chassis construction is now complete.
Wiring the Circuit
The next stage of construction involves wiring the
circuit. Mount the socket for V1 upside down on the base,
using 3/4” standoffs and 6-32 x 1” machine screws. This
will provide a convenient platform on which to pre-wire
components associated with V1. If you are not
experienced with soldering, search You Tube for “how to
solder.” You can also refer to the recent series, “Basics of
Soldering,” which started in the December 2014 issue of
SERVO Magazine ( www.servomagazine.com).
Use Wiring Diagram 1 to wire components
connected to V1’s socket. Wire the components in this
order: connect the wire from pin 5 to pin 8 first; then
connect R5, C3, and finally C5, layering one above the
other. The remaining components and wires can be added
in any order.
Follow the recommended lead lengths, allowing 1/4”
additional to wrap around the connecting terminal for
mechanical stability. For instance, if the lead length
specified is 3/8”, cut the lead initially to 5/8” (3/8” +
1/4”). Use spaghetti wire insulation on all bare leads
longer than 1/4”. Solder all connections.
When done, inspect all soldering joints, then remount
V1’s socket right side up.
Before moving to the next stage of wiring, mount the
front and rear assemblies to the base. Use Wiring
Diagram 2 to connect the wires and components
previously prepared on the V1 socket.
Now, add C7, R9, and the additional wires including
those to terminal strip TS2 and J4. Trim wires and leads to
their minimum length and use spaghetti wire insulation on
30 May 2015
■ FIGURE 6. Side view of
■ Wiring Diagram 2.
V1 and front panel
■ Wiring Diagram 1.
V1 socket wiring.