Border Patrol Power Supply Installation Instructions.

Model: Audio Innovations 1st and 2nd Audio amplifier.

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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 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, CABLE TIES, HEAT SHRINK, IEC MAINS LEAD.

TOOLS REQUIRED. SOLDERING IRON, PLIERS, M4 ALLEN KEY, SCREW DRIVER, SOLDER. (ELECTRIC DRILL AND 10mm BIT)

DISCONNECT THE AUDIO INNOVATIONS 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 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 coloured plastic sleeve from the on/off switch with a firm tug. Remove the 4 Allen bolts securing the lid and taking care not to damage the on/off switch, remove the lid.

Stage 1.
Depending on the age of the unit, next to the mains transformer, you will see either a green printed circuit board (PCB) sitting on top of two large electrolytic can capacitors , or two large electrolytic can capacitors connected via a 47,100 or 220 ohm 50Watt metal-clad resistor.
PCB version.
Locate the Bridge Rectifier (a black plastic rectangular object with four metal legs mounted on the PCB). Whichever capacitor this is located above will be referred to 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.
Hard-wired version

Locate the Bridge Rectifier (a black plastic rectangular object with four metal legs screwed to one of the large electrolytic capacitors)). 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. De-solder or unscrew the large metal clad resistor. Cut the two Red wires that come from the mains transformer to the two legs of the Bridge Rectifier marked (~) and insulate them with the heat shrink provided. 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 the stainless steel capacitor terminal screw through the circular tag on the RED cable and into the positive (+) terminal of Cap2 (make sure that the existing tag which contains the feeds to the output transformers is also re-connected). Repeat for the GREEN cable with the circular tag to the negative (-) capacitor terminal of Cap2. Screw down the two circular connectors tightly ensuring that they are not touching each other. You have completed the attachment of the High Voltage supply.

Stage 2.
Locate the bank of electrolytic capacitors at the front of the unit (10 4700mF/16V capacitors. Solder the blue wire to the positive terminal of the centre two caps and the yellow wire to the negative terminal of the centre two caps. This completes the connection to the relay inside the off-board supply.

DANGER. Check that the two circular connectors on the High Voltage supply are not touching each other.

Dress the new cables tidily and replace the lid. Replace the valves and the on/off switch 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 Audio Electronics
c/o Kaja Music Systems   Waldorf  Maryland  USA

Phone/Fax +1 301 705 7460
E-Mail. bp@borderpatrol.net