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, M4 ALLEN KEY, SCREW DRIVER, SOLDER, ELECTRIC DRILL, 10mm 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).

REMOVE THE VALVES NOTING THEIR POSITION.

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

Remove the base plate..

Stage 1.
Drill a 10mm hole in the back of the unit and fit the rubber grommet supplied. Be careful not to damage any internal components whilst drilling.

Feed the supplied 4-way cable through the grommet. Solder the RED wire to Pin 8 of the 5U4G octal valve base.
Unscrew the PSU PCB and solder the GREEN wire to the -ve terminal of the 220uF/450V electrolytic capacitor.

You have completed the attachment of the High Voltage supply

Stage 2.
Solder the BLUE wire to Pin 7 of the 6SN7 Octal valve base. Make sure all existing connections are maintained.
Solder the YELLOW wire to Pin 8 of the same base.

Dress the new cables tidily and replace the base. Replace all the valves except the 5U4G.

CAUTION: DO NOT REPLACE THE 5U4G

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 new 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.