Fisher KX 100 Service Manual

Page 1

KX-10

50-WATT _
STEREO CONTROL '
AMPLIFIER

Page 2

AVERY FISHER

Fund»: and Prurdu-J
MM! F in: Corporation

A Message From Avery Fisher

It is now almost twenty-seven years since we made and delivered our tirst instrument
for high fidelity reproduction oi radio and records. (That instrument Is now in the
Smithsonian Institution, Washington, D. C.) Beginning with that first unit it has been
our unfailing policy to manufacture only the very best of equipment, and to make that
equipment available to the widest possible audience.

it is with great pleasure that we are now able to furnish Fisher equipment in kit form,
thus bringing instruments of Fisher quality within the reach of a wide, new audience

The kit you have lost purchased represents the efforts of the linest single group of
engineers in the high fidelity industry. Our entire approach to the problem of designing
a kit was based on two simple rules. The first was that the quality must In every par»
ticular be on a complete par with the finest comparable Fisher equipment. as built in
our own Production Department. The second was that the method of assembly must
be so thoroughly simplified and organized that evan the most unskilled purchaser
could expect a perfect and result. No ellon has been spared to achieve these two
objectives and I know that the building at this kit will bring you a sense of accompllsh-
ment based on the pleasure of creating something line. and on the knowledge that here
is an investment that will bring virtually unnumbered years of musical enjoyment to
you and your family.

a iDiA may. nula tunnel-tartan

Page 13

STAGE 2

0U WILL. NEED TO SOLDER in this Stage, so if your soldering iron is Step 2-C
Ynot heated, plug it in now and read through the Stage while you [El
are waiting.

Cut a 34" length of bare wire and connect it between lug A
on llie front section of control P03 and Lug E on the rear
section.

Important: Step 2-D Connect the 4 black wire (the longer of the two} between
When you are to connect but not solder a wire or part lead to .3 lug E 1'13 A 9" the 70 396 0f control P03 and center lug B
you will be instructed to "connect. If the lead should be soldered 0f control P04"
after it is connected, you Will be instructed to solder". In short) can St 2 E Solder iS-two) One c d of the remainin black wire to center
nect" means connect and solder means connect and solder". ep - lug B «If control P0: The free end wilgl be connected later
Whenever you are instructed to solder" 3 lug, you will be told how '2
many leads are on that lug. For example, you might be instructed to Step 2-F Connect the green wire between lugB of the from. section of

Solder (S-two) one lead of R21 . . .. The "(S-two)" would indicate ,
that there was another lead previously connected and there should he 8
two leads on the lug at the time you solder. Nole that sometimes you

will insert a wire completely through a log {and then over to anothcrl. Step 2.6 Cut both leads oi one of the 22K ohm resistors, R40, (red,
in this case the wire will he treated as one even though both enrls. IE/ red! orange) to %.jnch.

are coming out of the lug.

In this stage you will begin to wire the dual Volume control P03, the Step 2-H
Loudness switch 56 and the Balance control P04, Use the parts in g
StrataPack 2 and, it necessary, refer to Fig. 8. If you have not yet
clone 50, open the hardware box and remove the solder spool, the roll
of bare wire, and the roll of insulating spaghetti.

P05 and lug C of P04. Dress it as shown in Fig. 2-1 and
solder [S-one] lug B of P03;

Solder (S-three] one lead of R40 to lug A on the front sec:-
tion of P03. Connect the other lead to lug F of switch 56. .

Step 2-]

[E

Ste?

Cut both leads of the remaining 22K ohm resistor, R39, to
l/2~incl't Solder (S-lwo] one load to lug E on the rear section

Locate figure 11, the front panel photograph, on separate sheet No. 2. 0f [03- Connect 0 other lead to lug C Dr 56-

. . . h l _' , . . l
The photo l3 Intended to e a re ercnce dont try to wire from it Connect the white wire between lug F on the rear section
Refer to Fig. 2-1 for the following steps: of P03 and lug A of P04. Solder lS-onel lug F of P03,

Step 2-A Solder (S-one) one end of the brown wire to lug D on the

Step 243

front section of control P03. Connect the other end of the
wire to lug E of switch 55. Dress the win against the front
panEl,

[ET

Solder (S-onc) one end of the red wire to lug H on the rear
section 0i P03. Connect the other end of the wire to lug B
on switch 56. Dress the wire against the panel.

11

This completes Stage 2 Notice that you now have a wire hanging
loose from the panel; you will connect more in the next few Stages
until you have quite an octopusl Eventually, all of these wires will be
connected into the main chassis circuits.

Page 30

Figure 11-1

23

Page 35

STAGE 13

OUR CHASSIS is almost ready to meet the front panel you previously
I wired! Before they get together the input jacks J1, J2, J3 and I4
will need to be prepared. You will do this now.

The ground connections on the input jacks 11, I2, 13 and J4 must be
connected together. You will use here wire and spaghetti to do this.
The first line in each step will indicate the necessary length of wire
and spaghetti.

Step 13- A 13/2- inch ban: wire; 1- inch spaghetti. Connect lug B of jack
J]. to lug E of jack J1.

Step 13-3 lye-inch bare wire; 1-inch spaghetti. Connect lug B of jack
J2 to lug E 01 jack 32.

Step 13-C 1-inch hare wire; a/3-ineh spaghetti. Connect lug B of jack

m J3 to lug D of jack 13.

519p 13-13 1-inch hare wire; 1errinch spaghetti. Connect lug D of jack
E J3 tolugFoijock J3.

Sfep 18- E 1-inch bate wire,- %-inch spaghetti. Connect lug F of jack

lg/ J3 to lugHof jack J3.

Step 13-F 1-inch hare wire; %-inch spaghetti. Connect lug B of jack
lEl J4- to lug D DE jack J4.

Step 13-6 1-inch here wire; a/g-iuch spaghetti. Connect lug D of jack
J4 to lug F oi jack J4.

Q

Step 13-H 17inch bare wire; 3/a-inch spaghetti, Connect lug F of jack
El 14 to lug H of jack J4.

33

Since none of these wires are soldered make sure the connections are
tight. Also, of course, be sure these (shorter) ground lugs are not
accidentally shorted to the longer hot lugs.

Now wire the grid circuits of the 7868 power output tubes as follows:

Step 13-] Cut all eight leads of the four 1K ohm resistors (brown,
black, red) to 1/2-in<:h.

Step Ia-K Connect one of these, as R61, from log 2 of socket V7 to
IE/ lug A of strip STlS. Solder. (S-ooe) lug 2 of socket V7.

Step 13-1, Connect another, as R63, from lug 6 of socket V8 to lug C
of strip STIS. Solder (S-one) lug 6 of socket V8.

Slep 13- M Connect another, as R62, from lug 2 of socket V9 to lug A
of strip STU. Solder (5- one) lug 2 of socket V9.

Step 13-N Connect the lust 1K ohm raistor, as R64, from lug 6 Di
Er socket V10 to lug C of strip 5T19.Soldor (S-one) lug 6
of socket V10.

Step 13-P Cut all eight leads of the four 330K ohm resistors (orange,
3 orange, yellow) to lé-inch.

Step 13-Q Connect one as H59 between lugs A and B of strip ST18.

El

Step Ia-R Connect another, as R57, between lugs B and C of strip
E, STIS. Solder [S-three] lug B ol strip STlS.

Step 13-5 Connect another. as R60, between lugs A and B of strip.
STIQ.

Step 13-T Connect the remaining resisLor, as R58, between lugs 13 and
M C of strip ST19. Solder (S-four) lug B of strip ST19.

Page 39

STAGE 15

You WILL CONTINUE in this stage to connect the front panel to the
chassis. Refer to Fig. 15-].

Step 15-A Connect the white lead from lug A of strip 5T4 on the front
panel to lug 3 of socket V1.

Step lS-B

IE/

Step I 54C

Connect the purple wire from lug B of strip 5T4 (NOT from
switch 51) on the iront panel to lug 3 of socket V2.

Locate the white-blue shielded cable from center lug B of
switch 53 on the front panel. Connect the center wire to lug C
of strip 5T5. Connect the ground wire to lug B oi strip STS.

Step 1 5-D Loente the black-white. shielded cable from center lug E oi
Ex' switch 53. Connect the center wire to lug G of strip 5T5.
Connect the ground wire to lug F.

Step 15-E Now locate the purple wire connected to lug 2 on the rear
'2 deck of switch 51 Connect this wire to lug E of strip 8T5;

Remove the Mack and the white wires from StrumPaek 15.
Step IS-F Solder (S-one) one end of the white wire to lug 6 on the
rear deck of switch 51. Connect the other end to lug A of
strip 5T5.

Step 15-6 Solder (s-one) one end of the black wire to lug 11 on the
rear deck of switch 51. Solder (S-one) the other end to lug D
of strip 5T5.

Remove the shielded cables from StratePack 15. Strip lid-inch of insu-
lation from the center wire at both ends. These cables will be run from

the from to the rear of the chassis. Keep them dressed neatly against
the chassis but do not insert them under any existing wires.

Sfep 'l 5-H Cut off the ground wire at one end of the white-black shielded

IE cable. Solder (S-one) the center Wire at this end to lug 10
on the [rent deck'oi switch 51.
Step 1 5-1

El

Position the cable as shown over to the right and down the
chassis. Solder (S-two] the ground wire to lug B of jack i3.
Solder (S-one] the center wire to lug A of jack 13.

519p 15-K Cu! Ofl the groundwire atone end of the, white-green shielded
cehle. Solder (S-one) the center wire, at this end, to lug 9
on the front deck of switch 51,

Step 15-l.

[Q/

r

Position the cable in parallel with the other one. Solder
(Educate) the ground wire to lug D of jack 13. Solder (S-one]
the center wire to lug C of jack 13.

513p IS-M Locate the white-blue shielded cable connected to lug A of
E, strip 5T2. Position it as shown. Solder (S-three) the ground
wire to lug F of jack l3. Solder (S-one] the center wire to

lug E of I3.

Step IS-N Position the white-brown shielded cable (from StrataPeck
E/ 15) as shown.Solder (S~two) the ground wire to lug H of
Bi Solder (S-onel the center wire to lug G of 13,

Step 15-? At the other and, bend the cable over to strip STIU. Connect
M/ the center wire to lug A oi STIO. Connect the ground wire
to lug B (of STID).

This completes the wiring of jack 13. Make certain the longer hot
and shorter ground logs are not shorted to each other by solder or
here wires.

37

Page 48

Figure T9-I

4O