McIntosh C108 -, Инструкция по эксплуатации

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Channels 1 and 2:
Channels 1 and 2 are each terminated by a potentiometer. These potentiom-
eters are screw driver adjustments on the back panel and should be used to reduce
signal input to these channels if in excess of . 1 volts. Correct adjustment occurs
when the sound level of channels 1 and 2 is equivalent to that of channels 4 or 5.
High impedance sources, such as crystal microphones and the detector output of
tuners, may be connected directly to these channels since they have an input
impedance of 660, 000 ohms.
Channel 3:
Channel 3 is a high gain microphone channel having an input impedance of
100, 000 ohms. The input to this channel should not exceed 60 MV. Low impedance
microphones in conjunction with an input transformer, such as the McIntosh M-107
(ATI-1), may be used on this channel.
Channels 1, 2 and 3 provide flat amplification from 20 cycles to 20, 000
cycles with the bass and treble controls in their central position, and the treble
compensation switches in the up position. These controls may be used to alter the
response of these channels as shown on page 9.
Channels 4 and 5:
Channels 4 and 5 are equalized for use with magnetic phonograph cartridges.
The degree of equalization may be varied with the bass and treble compensation
switches as shown on pages 8 and 9. The bass and treble tone controls may be
used to supplement these compensation switches.
The inputs of channels 4 and 5 have been terminated to give flat response from
the Pickering and Audax Polyphase cartridges respectively. If cartridges of other
manufacturers are used, the terminating resistors should be replaced by values
recommended by the manufacturer. For example, the 47, 000 ohm terminating
resistance of channel 5 should be replaced by 12, 000 ohms if the G.E. reluctance
cartridge is used. If it is desirable not to alter the C-108 an 18, 000 ohm resistor
may be connected across the G.E. cartridge in the line to the cartridge.
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