17
q F rom the rear side of the chassis screw on the switch nut using a
5/16” nut-driver, lightly tighten it. Installation of the lock washer is
optional. These switches can be delicate, be careful not to over
tighten the nut. Also note that the switch can be knocked and
damaged if you are not careful while handling the chassis.
RCAJack to Mute Switch Wiring:
H e re is where your nimble little fingers will give you an edge over the
next guy. If you are a practicing brain surgeon or the S.W. A . T. team
bomb specialist, or simply an accomplished needle nose master, you
may find these next few steps entertaining. For the rest of you, just
take your time, what’s the hurry, I have not been timing you.
q Take a good look at the photo of these wired components and start
by taking one of the cut resistor leads and connecting it to one of the
eyelets of the RCA jack solder lugs.
q Crimp the lead into position through the hole on the RCA solder
l u g .
q Do not solder it into position yet. The signal common wire needs to
be inserted into this hole later.
q Do the same on the opposite RCA solder lug.
q Bring these two leads together onto the center terminals of the Mute
switch, bridging the left and right center switch terminals together as
well. Trim the length of the leads as necessary.
q C a refully solder these center terminals of the Mute switch to the two
g round leads.
q Find two more cut leads long enough to fit between the RCA center
signal pin and the top lug on the Mute switch. See the photo as
n e c e s s a ry.
q One end of these leads wraps around the Mute switch top term i n a l
lug closest to its adjacent RCA I/P jack, and the other end is then
i n s e rted into that RCA jack center pin hole.
q Repeat this for the opposite channel.
q At this time solder the leads at the Mute switch only.
Chassis Solder Lug:
The single point chassis ground for this amplifier is located dire c t l y
between the RCA jacks and above the Mute switch, on the inside of
the chassis. If there is paint on the standoff top, it must be re m o v e d .
This is a good time to ensure that all chassis ground connection point
s t a n d o ffs are free of paint. Note the 4 diff e rent standoff locations to
check for unwanted paint.
q solder lug
q #6-32 1/4” zinc scre w
q If this standoff has no paint on its top surface, mount the solder lug
using a #6-32 1/4” zinc screw and bend the lug out to be like the
p h o t o .
q Next, using one more cut resistor lead, wrap one end to the solder
lug on the chassis standoff. The other end connects to the center of
the ground connections made on the Mute Switch (center pins).
q Solder the connection at the Mute Switch only at this time.
Input wiring:
M o re fun to come doc’. We are now going to pre p a re both ends of the
Signal I/P cable and attach one end to the RCA jacks.
q Shielded 4 Conductor Input x 24” (710mm) (Sig)
Signal cable
q 3/16” Heatshrink tubing 1/2” (13mm) x 1
q Check that this cable is no longer than 28” (710mm)
q On one end of the cable, to be dubbed ‘the long end’, remove 1.5”
(38mm) of the outer insulating jacket. This is the signal input end of
the wire .
q On the other end of the cable, to be dubbed ‘the short end’, re m o v e
1.25” (32mm) of the outer insulating jacket.
q With a sharp fine tip equipped utensil like a safety pin, care f u l l y
unbraid the outer braided shield of this cable. Use the tip to
methodically comb back one braid bundle at a time. Settle back in a
c o m f o rtable chair because will take 5-10 minutes each end to do.
q Do the same on the opposite end.
q Once you have unbraided the shields back to the jacket, on the
‘long end’ straighten and twist the shield wire into a nice single
conductor and cut it to 1” (25mm) in length. Tin this end.
q On ‘the short end’ we do not need the shield at all. Please trim it right
back to the outer jacket.
q At both ends, trim off the cotton filler material with your side cutters.
q Notice the colour coding of the 4 conductors. 1 pair has solid
colours and the other is not, it has a stripe. Twist into like pairs and
p re p a re and tin the ends by stripping off the standard 1/8” (32mm) of
the wires’ jackets.
N o t e : These conductors are not tin plated copper wire so you must
be sure to tin the ends thoro u g h l y. The conductor jacket is
polyethylene so it can take the heat.
q Basically we now have a blue and a white wire in each twisted pair.
For clarification, we will use the SOLID Blue and White wires as the
Left channel, and the Blue wire will be the signal common for this pair.
q The first connection to make with ‘the long end’, will be the Solid
Blue wire to the Left channel RCA jack solder lug (this is the jack to
your right). Simply slide this Solid Blue wire into the open solder lug
hole and solder both conductors into place.
q Do the same on the Right channel connecting the Blue w/white
stripe wire to the Right RCA solder lug hole.
q To connect the remaining White wires, try to maintain the twisted pair
and position the wires into the holes of their respective RCA signal
input pins.
q Solder these connections to the RCA jacks.
q Almost there, one more connection to make. That would be... to
connect the shield wire. Not sleeping I hope.
q Locate the chassis solder lug and notice that nice larg e
accommodating hole just waiting to be used. Solder the shield into
this position.
q Finally we will dress this cable by sliding a 1/2” (13mm) piece of
3/16” shrink tubing onto the cable from the free end. Slide it over the
exposed shield and wires as far as you can neatly do, then shrink into
p o s i t i o n .
q Te m p o r a r i l y, you may want to tape this cable to the inside of the
chassis along its walls to the right side and then the front. This will
keep it out of harms way, not to mention testing your patience.
Well, was the operation a success? I hope so, because we are not
going back in.
IEC - AC Power Socket:
The IEC socket is the next component to be installed. I am sure that
you know that this is where the AC power cord is connected, but this
is also where the main power fuse is housed. Notice the small sliding
drawer below the receptacle opening, on the front side. You may even
notice that the fuse drawer will not open if the power cord is installed!
We will need to pre p a re and attach a few wires to this IEC socket
b e f o re we install it into the chassis, so here we go.
q Black 18awg 4”(100mm) x 1 wire ‘A’
q Black 18awg 2”(50mm) x 1 wire ‘C’
q G reen 18awg 2.5”(64mm) x 1 wire ‘B’
q Heat-shrink tubing 1/8” .5” (13mm) x 3
q IEC Socket x 1
q M3 10mm (3/8”) Blk CS screws x 2
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