Formula Sound FSM-400, User Manual

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Page 5
Service and Configuration
Several internal options are available on the FSM-400. These should only be undertaken by
qualified personnel.
Always remove the power cord before removing covers.
To gain access to the internal parts of the FSM-400 remove 4 screws from each of the two
side covers which surround the FSM-400. This will give access to the internal jumpers and
adjustments.
Channel options (remove top cover).
Channel 1. One jumper fitted towards the top of the channel pcb provides microphone
phantom power selection. Pcb notation shows positions.
Channels 2-4 - N.B 2 jumpers per channel must be moved
4 jumpers located behind the input selector switch provide selection for input A and B to be
set to low gain. They are labelled AR (chan A right) BR (chan B right) AL & BL etc. The low
gain setting is with the jumper positioned away from the switch.
Ensure that the correct jumpers are moved and they are correctly located on the pins.
Removing all the jumpers will set inputs A and B to the low gain settings .
2 jumpers provide selection for the A input to be a flat line input or an RIAA magnetic
cartridge input. Pcb notation shows the position for the jumpers.
Ensure that both
jumpers are moved to the correct positions and located correctly on the pins.
MAINS VOLTAGE SELECTION - The FSM-400 can be switched to operate on
220-240Vac or 110-120Vac. The selection is by a slide switch mounted on the power supply
pcb at the mains transformer end. Notation on the pcb and switch clearly show the switch
position. If you need to change the mains operating voltage you will also need to change the
main fuse. The fuse is located in a slide out drawer which is part of the mains connector. The
connector is mounted on the mixer rear panel.
Fuse sizes 220-240v operation = 315mA anti surge 5 X 20mm fuse
110-120V operation = 800mA anti surge 5 X 20mm fuse
Removing the top cover also exposes the right end output pcb. The sub bass adjustment is
located on this board - and is controlled by 1 jumper located above the sub bass jack socket.
Adjacent notation shows the positions.
Fader Replacement
Should fader replacement become necessary any of the faders can be replaced by removing
the bottom side cover. Remove the 2 screws securing the fader and disconnect the
connector. Replace with a new fader assembly.