install a 20AWG buss wire through all “sleeve” terminals as well as the top “tip” terminal. Tack
solder in place the wire in all terminals (photo 5.28a).
Step 2
– On the upper jack (HI input), install a 1M resistor between the top
“sleeve” terminal (extending this lead to the grounding washer) and the bottom
“tip” terminal (extend this component lead to the lower jack). Solder all upper (HI
input) jack terminals, including grounding washer.
Step 3
– Thread the lead from the upper jack 1M resistor through to the lower (LO
input) jack's top “tip” terminal.
Step 4
– Locate the two 33K / 1/2W resistors and twist together one lead from
each resistor.
Step 5
– With the other two open resistor leads, connect them close to the two
lower jack “tip” terminals and solder both in place.
Step 6
– Remove the normal channel jack assembly from the vibrato position and
place on the workbench.
Step 7
– Cut a 6 1/2” length of shielded wire and strip 1” from each end.
Step 8
– For the tube socket end, carefully cut and remove the exposed shield.
Step 9
– Cut a 3/4” length of 1/8” heat shrink and install over the end of the wire.
Step 10
– Shrink the heat shrink to cover where the shield was cut (photo 5.28c).
Step 11
– Strip and tin the center conductor.
Step 12
– For the jack end of the shielded wire, separate the shield from the
center conductor.
Step 13
– Tightly twist the shield together and tin.
Step 14
– Remove the thin black conductive plastic shield from around
the center conductor.
Step 15
– Strip 1/4” from the center conductor and tin.
Step 16
– Solder the center conductor to the point where the two 33K
resistors twist together and trim any excess twisted component leads.
Step 17
– Tack solder in place the shield of the shielded wire to the lower
“sleeve” terminal of the bottom (LO input) jack.
Step 18
– Cut a 4” length of 18AWG black wire and strip and tin each
end.
Step 19
– Solder one end of this wire (along with the other wires
connected to this terminal) to the lower “sleeve” terminal of the bottom
(LO input) jack.
Step 20
– Make sure all terminals and connections on these jacks are fully soldered.
Step 21
– Install the completed assembly into the normal input jack position (photo 5.28b).
Step 22
– Run the shielded cable along the chassis edge from the jack assembly to V1 and
solder the heat shrink end to pin 2 of V1 (photo 5.28d).
photo 5.28c
TubeDepot.com 27
photo 5.28d
Photo 5.28d shows a 10pfd silver mica cap between the input terminal 2 and ground. This
is a great mod for reducing unwanted radio station reception in the amp.
MOD
