Arcam A60 - Manual (Page 11)

Cartridge loading modules
These are purely passive modules designed to modify the input impedance of the amplifier in
order to obtain the best match with the cartridge in use. The ULM/M is designed for use with
moving magnet cartridges and the ULM/C (to be used in conjunction with the MC60 pre­
amplifier board) is for use with moving coil types. Each is user adjustable via switches on the
module and offers the facility for additional components to be wired on to provide customised
loads.
The loading module should be plugged into the A60-I- in the position shown in the diagram
opposite.
DO NOT OPERATE THE LOADING MODULE SWITCHES WHEN THE AMPLIFIER IS
SWITCHED ON. THIS MAY DAMAGE YOUR AMPLIFIER OR YOUR LOUDSPEAKERS.
It must be emphasised that these passive modules mainly affect the sound balance and
frequency response. They will have little or no effect on the sensitivity of the amplifier except
with some moving coil cartridges where lower resistance loadings may reduce the cartridge
output significantly and necessitate a higher volume control setting.
Most cartridges will perform satisfactorily without any loading module.
MC60 moving coil pre-amplifier
The MC60 is designed for use with a wide range of “low output” moving coil cartridges. Its
input impedance is adjustable by using the ULM/C module as described above. To install the
MC60 the following procedure should be followed:
1 Switch off and disconnect the mains supply to the A60+ and remove all input and output
connections.
2 Remove the wooden cover (see above)
3 Remove the linking socket from the 8-way plug near the disc input socket (see diagram on
page 8) and retain this in a safe place.
4 Insert the MC60 board into the 8-way plug ensuring that all pins engage correctly and that
the board is in the correct orientation (see diagram on page 8).
5 Replace the wooden cover and re-connect as before.
In the SYSTEM BLOCK DIAGRAM:-
O the C.D. input is at 200mV nominal level and has additional h.f. filtering to remove unwanted ultrasonic signals
O the tuner and tape are at lOOmV levels and feed via the selector switch directly into the volume control
O the tape input, in addition, feeds via its own 100k ohm tape presets
O the disc input signal is amplified to lOOmV to feed via the selector switch directly into the volume control
O the mono switch has two functions: it monos separately the feed to the power amplifier and the feed to the tape and
aux outputs