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MI-3
SCHEMATIC NOTES
AUDIO DRIVER
P.C. BOARD 043-984
I. Unless otherwise specified: Resistance values are in ohms, 1/2 watt, and 10% tolerance;
capacitance values a re in microfarads (µF).
2 . Printed circuit board components are outlined on the schematics by dotted lines. The
circIed numbers around the dotted lines correspond to the numbers on the PC Board
layouts.
3. The terminal number ing of rotary switches is for reference only.
4. All voltages indicated on the schema tics are measured under the following conditions:
a. Use of an 11 megohm input impedance VTVM.
b. All voltages ±10% with respect to chassis ground.
c. No signal at input or antenna terminals.
d. AC
Input
at 117
volts,
50/60
Hz.
e. Mode selector at test position.
5. In
units with
Serial
No's
below
10E26,
two
neon
bulbs (Mclntosh Part
No.
058-002)
are
used in place of R59 -
6. In units with Serial No's from 10E26 to 15E00, R60 and R61 are used.
7. In units with Serial No's below 13E00, a 6W4 rectifier tube (Mclntosh Part No. 165-016)
is used in place of SR7 -
8. In
early units,
PC
Board
043-984
and R43 and R50 are not
used.
The arm of
R48A
is
connected directly to pin No. 2 of S1 and the arm of R48B is connected directly to C7.
