User Guide

C20
Schematic
(Schematic
No.
SC117-201)
NOTES:
(1)
THlS
SCHEMATIC
APPLIES
TO C20
PREAMPLIFIERS
WITH
SERIAL
NUMBERS
6L700
AND
ABOVE.
(2) ALL
ROTARY SWITCHES
ARE
SHOWN
IN THE
EXTREME COUNTERCLOCKWISE
POSlTION.
(3) ALL
PUSHBUTTON
SWITCHES
ARE
SHOWN
IN THE
"OUT"
POSITION.
(4)
RESISTOR
VALUES
ARE IN
OHMS
±10%,
½WATT
EXCEPT
AS
NOTED.
(5)
CONDENSER VALUES
ARE IN MFD FOR
NUMBERS LESS THAN ONE,
AND IN
MMFD
FOR
NUMBERS GREATER THAN ONE.
(6) IN
SOME UNITS C104
MAY BE
FOUND
AS TWO
SEPARATE
2000
MFD/15V
CONDENSERS.
(7) A
RESISTOR
IM
SOME
UNITS
MAY BE
USED
AT
THIS
POINT
TO
ADJUST
THE
VOLUME
CONTROLS
TRACKING
CHARACTERISTlC.
THE
VALUE
IS
MATCHED
TO THE
PARTICULAR VOLUME CONTROL
USED
*
THESE
COMPONENTS
HAVE
A
CLOSE TOLERANCE
ON
THEIR
VALUE,
OR
HAVE
SPECIAL
CHARACTERISTICS
SUCH
AS
LOW
NOISE
OR A
SPECIAL RESISTANCE TAPER.