CL-35-Mk3
ULTIMATE
HIGH
FIDELITY
STEREO
COMPONENT
[l[]]OOOO[)G[jO
CL35 /m
CONTROL CENTER
SERVICE
MANUAL
CIRCUIT
DESCRIPTION
'.
1/2
12AX7
ECC83
1/2
12AX7
ECC83
1/2
12AU7
ECC82
200V
2«JV
l.OK
t------;jw~~::l
Signal
out
put
2",H
non ieverted
in put
fig. -1
Equalizer Amplitier
inverted
input
The
circuit
is
shown
in
the
Fig.
1.
This
amp
has
not
standard
method
of
Feedback,
about
which
special
explanation
is
made
hereunder.
Fig.
2 shows
its
concept,
wherein
A-3 means
cathode-follower
with
its
gain
at
OdB.
While
A-2
has
+39dB
and
therefore
the
gain
is
+39dB
thru
A-2 and A-3.
At
A-I
the
output
impedance
is
110K ohms by means
of
electric
feedback
from
the
cathode
side.
Local
feedback
by 2.2M
ohms
can
be
stipulated
as
th~
formula
Beta
=
1/19.8
and amount
of
NF
is
14dB.
Therefore
the
gain
is
+25dB
thru
A-2
and
A-3, and
input
impedance
becoms
210K
ohms.
At
A-I
load
is
120K ohms and
gain
is
+32dB, and
therefore
the
total
gaLn
is
57dB.
Fig.
3 shows
R.I.A.A.
complex.
The.
total
NF
shall
not
be
levied
below
the
cut-off
frequency
of
50Hz.
In
the
case
of
triode
it
is
possible
to
suppress
the
distortion
below
the
sensing
level
under
flg.-2
small
signals.
The
present
operation
point
lies
at
the
total
distortion
balance.
~
II
,.
..
..
330lPF
\~PF
II II
l;~F
rr
220PF
2201<
."
~
phono
position
MlC
position
This
amp.
plays
the
role
of
mic.
amp.
as
well.
fig.-3
1/2
12AX7
ECC83
1/2
12AX7
ECC83
82K
18K
10K
.--------_------Cl
+21OV
fig.-5
output
1/400V
non
inverted
input
0-----11-
inveried
in~ut·
o--~r-1IH
fig.-4
Fig.
4 shows
the
circuit,
where
the
2nd
stage
is
constituted
by
dual
amps
of
local
feedback.
The
feedback
circuit
is
shown
in
Fig.
5.
~ow
Frequency
Trimmer
operation
is
done
by
the
feedback
circuit.
At
the
G)
position
roll-off
takes
place
at
100Hz
and
cut-off
takes
place
at
250Hz,
while
at
the
()
position
cut-off
commences
at
100Hz
and
roll-off
starts
at
220Hz.
25lJ<.
B
1/2
12AX7
ECC83
Tone
Control
'"
~
§
~
l.
05mA
245V
Made
of
LUX's
exclusive
NF
type.
All
circuits
are
shown
in
Fig.
6.
This
is
standard
tone
control
with
LUX
amps.
Incidentally
operation
of
tubes
at
this
stage
depends
on
distortion
and
level
of
grid
current.
Signal
output
1/400V
140V
10001<
Signol
input
fig.-6
fig.-]
~271'
Signnl ovtp'ut
Low
Cut
Filter
As
per
Fig.
7.
this
is
-12dB/oct.
filter
composed by
2-stage
coupling
of
CR.
This
filter
frequency
depends
on
the
level
set
volume,
and
the
standard
point
lies
at
the
5th
decrement
from
the
max.
position
(-6dB)
.
"
2
?45V
~':!!2'!!_~~2.:.
Composed by
cathode-follower
as
per
Fig.
8.
The
bias
is
fixed
at
this
stage.
Noise
"
of
zener
is
reduced
down
to
the
aliowable
Signal
level
by
high
cut
filter.
'Jutp.Jl
fig.-S
4700P
4.7K
5.6K
92rnH
~~~~-g,!!_~~~!~::
Shown by
Fig.
9,
and
attenuates
-12dB/oct.
by
means
of
LC.
The
filter
frequency
is
decided
inview
of
load
and
lOOK
ohms
+ 200pF
(main
input
impedance
and
shield
wire).
Signa~
o----c)-.M)-----f--------1I------<O
S~~~pa~t
input
270P
470K
fig.-9
6.52V
Fig.
10
shows whole
circuit,
which
is
made
by
whole
stage
direct
coupled
pure
complementary
SEPP
configuration.
Q2
retains
the
fixed
current
load
triggered
by
Q3
and
yields
the
output
of
about
100rnW
into
8 ohms.
Ql
Q3;2SC1222
Q2
;2SAMO
Q4 ; 25C375
Q5 ;2SA562
Signol
output
~~g~:l
0--II-.Mf'-~-+___I(
p
2.
2/
22K
t---t--N'I--+-:-::C::c-1--lII---r--G
1.2K
fig.-lD
3
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