Border Patrol Power Supply Installation Instructions.

Model: Audio Innovations series 700.

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ELECTRICAL KNOWLEDGE IS REQUIRED IN ORDER TO PERFORM THIS CONVERSION SAFELY. POTENTIALLY LETHAL VOLTAGES ARE PRESENT. WE CANNOT BE HELD RESPONSIBLE FOR ANY ERRORS OR ACCIDENTS THAT MIGHT ARISE WHEN PERFORMING THIS CONVERSION. IF YOU HAVE ANY DOUBT ABOUT YOUR ABILITY TO PERFORM THIS CONVERSION SAFELY PLEASE CONTACT US FIRST.

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 AND 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 (15 mins is usually sufficient).

REMOVE THE VALVES TAKING CARE TO NOTE THEIR POSITION.

Installation of the power supply is completed in two stages. The first stage is the disabling of the on-board high voltage supply and the connection of the new off-board supply and the second stage is the connection of the relay to switch the new off-board supply on and off from your current on-off switch. Remove the knobs and the selector switch/ volume pots/mains switch mounting nuts (later units have these switches mounted on the under tray rather than the lid so removal of these nuts is not necessary). Remove the 4 Allen bolts securing the lid and taking care not to damage the mains switch remove the lid.

Stage 1.
There are two green printed circuit boards inside the unit, a large full width board carrying the valve bases and a smaller board located towards the back of the amplifier carrying power supply components. Locate the Bridge Rectifier (a black plastic rectangular object with four metal legs) mounted on the small PCB. Whichever capacitor this is located above will be referred as Cap1. The other capacitor which is connected to the output transformers will be referred to as Cap2. Remove the four stainless steel screws which secure the board to the capacitors. Locate the 47ohm ceramic dropper resistor, de-solder it from underneath and remove it.

Cut the two Red wires that come from the mains transformer to the Bridge Rectifier and insulate their ends with the heat shrink provided. Do not remove or damage any of the other wires leading to and from the board. Re-fit the board using only the screws for Cap1. Drill a 10mm hole either in the underside or the back of the unit and fit the rubber grommet supplied. You may find an existing hole that can be enlarged on the bottom of the unit. Be careful not to damage any internal components whilst drilling. Feed the supplied cable through the hole and secure in place with the cable ties provided. Feed one of the left over stainless steel screws through the circular tag on the RED cable, through the PCB hole marked positive (+) and into the terminal of the Cap2. Repeat for the GREEN cable with the circular tag through the PCB to the negative (-) terminal of Cap2. Screw down tightly ensuring that the tags do not touch each other. You have completed the attachment of the High Voltage supply.

Stage 2.
Locate the bridge rectifier on the full width circuit board. Locate the accompanying 4700mF/16V (or similar) electrolytic capacitors. Solder the blue lead to the positive terminal (marked +) of the capacitor and the yellow lead to the negative terminal (marked either - or with a black band). This completes the connection to the relay inside the off-board supply.

DANGER: Check that the two circular connectors on the H.T. supply are not touching each other.

Dress the new cables tidily and replace the lid. Re-fit the selector switches and volume/balance pots if necessary, replace the valves and connect the umbilical lead to the new off-board supply. Replace the mains lead to both units. Switch on the Audio Innovations 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.

BorderPatrol 63 Berriedale Avenue, Hove Sussex England
Tel/Fax +44 (0) 1273 276716