- MARK LEVINSON INSTRUCTION MANUAL PREAMPLIFIER JC-2

TAPE 1/TAPE 2 - selects either tape input 1 or tape input 2 for the input/
monitor switch.
MONO/STEREO - selects either a mono or a stereo mode at the main outputs.
HIGH/LOW - selects either 21dB gain (HIGH) or 11dB gain (LOW) in the
output stage. Line level inputs should generally be used only with the
low gain setting. Low level phono inputs can be used with either HIGH or
LOW depending on the output level of the phono cartridge. If when using
the low gain position, the output level control is set close to maximum
for a pleasing level, i. e. above 7 or 8, turn down the output level and
switch to the high gain position. This will give a broader range of
operation for the output level control. Conversely, if in the high gain
position the output level control is set below 1 or 2, switch to the low
position.
This switch does not affect the tape outputs.
BALANCE 1 and 2
- these switches are used to precisely set channel balance
for a correct stereo panorama. There is a total range of nine dB in one dB
steps for each channel. The normal position for these controls is 0dB.
At this position there is a gain in the output stage of 11dB in the LOW
gain setting, and of 21dB in the HIGH gain setting.
These controls do not affect the tape outputs.
OUTPUT LEVEL
- adjust volume at the main outputs for both channels
simultaneously.
5. OPTIONS
5.1. The JC-2 Modular Plug in Phono System (from S/N 1122)
The basic JC-2 Preamplifier contains two extremely high performance
ultra-low noise amplifiers encapsulated in special thermal epoxy. The
external regulated power supply and the internal active filter in the
JC-2 make it possible to incorporate very high gain phono circuitry with
great immunity to hum pick-up and other power supply noise. A series of
plug-in cards is available, containing equalization and other circuitry
to match the characteristics of the phono section to practically every
cartridge available now and in the future. The basic amplifiers and the
plug-in cards feature gold-plater pins and sockets for highest reliability.
As part of this system, MLAS offers a revolutionary moving coil cartridge
amplifier which provides DIRECT input, WITHOUT BOOSTER AMPLIFIER, of even
the lowest output MC cartridges. The input stage accepts 7 millivolts at
1kHz, and 70
millivolts at 20kHz, which allows enough headroom for the
highest peaks it is possible to encounter (80cm/s). Transient distortion
has been greatly reduced, giving a significant increase in transparency
and openness of sound. This system includes one JC-1SM plug-in card and
two Universal Phono plug-in cards (see below).