McIntosh MA5100 Service Information

SCHEMATIC NOTES
MA 5100
Unless otherwise specified: Resistance values are in ohms, 1/2 watt, and 10%
tolerance; capacitance values smaller than 1 are in microfarads (mfd); capacitance
values greater than 1 are in picofarads (pF) ; inductors are in microhenries (µH).
Printed circuit board components are outlined on the schematics by dotted lines.
The circled numbers on the dotted lines correspond to the numbers of the PC board
layouts.
The heavy lines on the schematics denote the primary signal path.
The terminal numbering of rotary switches is for reference only.
All voltages indicated on the schematics are measured under the following condi-
tions :
a. Use of an 11 megohm input impedance VTVM,
b. All voltages ±10% with respect to chassis ground.
c. No signal at input terminals,
d. AC input at 117 volts AC, 50/60Hz.
e. Front panel controls at:
Input Selector
Mode Selector
AUX
STEREO
Volume
Power
MAX
ON
All other controls in normal position.
1. In units with serial numbers below 46H01, the output monitor PC board is not
used.
2. In units with serial numbers below 44H50: R256 & R25? are not used; R254 &
R255 are 120 ohms; transistors Q205 & Q206 (132-021) and pots R221 & R222
(134-120) are used; the emitter of Q2l5 & Q216 is connected as shown by the
dotted line; C221 & C222 are used.
3. In early units, C5 & C6 were 39pF.
4. In units with serial numbers below 30H15: L201, L202, R241, R242, C215,
C216, C217, and C2l8 are not used; C227, C228, C229, C230, C231, and C232
are used; R229 & R230 are 100 ohms; C201 & C202 are 330pF.
5. In early units, C207 & C208 were 200µF, 3V (part number 066-086).
6. In units with serial numbers below 30H30: D201 & D202 were two diodes
(part number 070-022).
7. In units with serial numbers below 28H00: C3, C4
}
C5, C6, R9, R10, and
R314 are not used.
8. In early units, C308 & C309 were 10,000µF, 40V (part number 066-090).
9. In units with serial numbers below 24H05: R237 & R238 are .47 ohms; R233
& R234 are 220 ohms; C211, C212, C213, and C2114 are .01µF.
10. In units with serial numbers below 23H7S: D211, D212, D213, and D214 are
not used.
11. In units with serial numbers below 22H00: R227 & R228 were 1K, 10%, 1W,
12. In units with serial No's below 54H60: R254 and R255 are 18 and F201,
F202, F203j and F204 are 3A fuses. (Part Ho. 089019)
LOCATION OF TRANSISTORS NOT ON PRINTED CIRCUIT BOARDS

McIntosh MA5100 Specifications

General

Frequency Response	20Hz to 20kHz
Input Sensitivity (MM)	2.5 mV
Signal to Noise Ratio (MM)	70 dB
Signal to Noise Ratio (Line)	80dB
Output Impedance	4, 8, 16 ohms
Input Impedance (Line)	250k ohms
Input Impedance (MM)	47k ohms
Total Harmonic Distortion	0.5%
Input Sensitivity (Line)	250 mV
Type	Solid State Integrated Amplifier
Power Output	45 watts per channel