Mark Levinson JC-2 - Manual (Page 9)

NEW DEVELOPMENTS IN THE JC-2
JC-2 Preamplifiers starting with serial number 2148 differ from previous units.
They are equipped with lemo connectors, a new power supply (PLS-150), two phono inputs and new
phono plug-in cards.
PHONO SECTION
The standard systems are now A3, D5 and d6. The plug-in cards contain a two-station
program switch for selection of input and gain characteristics.
System Rocker Switch Function Open Closed
A3 1 input impedance 100k 50k
2 gain 30dB 40dB
D5 1 CRC* CRC out CRC in
2 gain 54dB 60dB
D6 1 CRC CRC out CRC in
2 gain 60dB 66dB
System A3 permits optimum loading for cartridges such as the B & O, Grace and Audio Technica
types which are designed for 100kOhms termination. Certain high output moving coil cartridges such
as the EMT, the Supex 901, the Satin and the Ultimo, may be used in more efficient systems with the
40dB gain implemented.
System D5 and D6 are identical except for the gain. Both offer switchable CRC for flattening the high
frequency response of certain cartridges like the Fidelity Research FR-1Mk3, the Ortofon SL15
(original type), and certain other moving coil types (high frequency response varies from batch to
batch of most MC cartridges.)
System D5 offers 54 and 60dB gain positions. 60dB gain is the same as previously
supplied by our System D and D1. 66dB is especially intended for use with low output MC cartridges
such as the FR-1 Mk2 and Mk3 when used with inefficient systems requiring more voltage gain in the
preamp.
WHEN NOT OTHERWISE SPECIFIED, SYSTEM D6 WILL BE DELIVERED.
Selecting the appropriate gain for the record output level may be accomplished by selecting the right
phono plug-in systems.
Note:
System A3 cards MAY BE USED in earlier units. System D5 and D6 MAY NOT BE USED in
earlier units. To accomplish the switching facility, differences had to be incorporated in the modules
which DO NOT ALLOW Compatibility. For detailed information, contact the factory.
For any questions concerning individual units, give us the SERIAL NUMBER of JC-2 in question.
*CRC: Cartridge Resonance Compensation. The CRC circuit supplied rolls the high frequency
response at 6dB per octave, -6dB at 20kHz. In particular, this curve has been successful in improving
the performance of the FR-1Mk3. Other corrective curves are available on request.