PLEASE READ THE INSTRUCTIONS FULLY BEFORE COMMENCING


KIT CONTENTS. POWER SUPPLY, 4 WAY TERMINATED CABLE, RUBBER GROMMET, HEAT SHRINK, IEC MAINS LEAD.


TOOLS REQUIRED. SOLDERING IRON, PLIERS, M3/4 ALLEN KEY, SCREW DRIVER, SOLDER, ELECTRIC DRILL, 10mm DRILL BIT.


DISCONNECT THE AMPLIFIER FROM THE MAINS BEFORE BEGINNING. If the unit has been used recently, allow sufficient time for the power supply capacitors to discharge before beginning (5 mins is usually sufficient).


This is a two stage conversion. Stage 1 disables the on-board high voltage supply and connects the new off-board supply. Stage 2 enables the new supply to switch on and off from the amplifier.

Remove the amplifier lid.

Stage 1.
The power supply components are located on a PCB on the left hand side of the chassis. Locate the 47R resistor nearest to the Bridge Rectifier BR1 and remove it. Cut the two (red?) wires that come from the mains transformer to the Bridge BR1 and insulate them using the heat shrink provided. Drill a 10mm hole in the back or bottom of the amplifier, fit the rubber grommet and feed in the umbilical cable. Connect the RED wire to the +ve terminal of C2 and the GREEN wire to the -ve terminal of C2.
This completes Stage 1.

DANGER: The two Red wires carry high voltage AC. Make sure they are fully insulated.

Stage 2.
The large mains transformer on the left of the chassis has a winding marked either 0-3.15-6.3 or 3.15-0-3.15. Bare back the insulation on the two outside terminals and solder the BLUE wire to one terminal and the YELLOW wire to the other. DO NOT REMOVE OR DISTURB ANY OTHER CONNECTIONS TO THESE POINTS. This completes Stage 2.

Dress the new cables tidily and replace the lid. Connect the newly installed umbilical lead to the off-board supply. Replace the mains leads to both units. Switch on the amplifier as usual. Your amplifier should now be ready to play. The valve supply will take longer to come up to operating voltage than the old supply but this will have the advantage of lengthening the life of the valves.