Before you start
You can print silkscreen images of both Amplifier and PS boards from these links:
Do not use these images for drill templates. These images are enlarged to make the component numbering clear. Drill templates can be found in the Boards section.
It's a good idea to study both boards and the components for each one. Also, look at the Amplifier Schematic and PS Schematic diagrams to locate each part on their respective layouts. Measure each resistor before you install it to make sure that you're reading the code properly.
PS Board Assembly Instructions
Solder the components to the board from lowest profile to highest, roughly in this sequence:
- Resistors that lay flat on the board and the zener.
- The film capacitor (C2), the connectors, the trimpot (P1), and the resistors that stand vertically (R7 and R8).
- The tube socket.
- The mosfets and their heatsinks.
- The electrolytic capacitors.
- Insert the rectifier tube.
WARNING: Always use heatsink mounting kits for the mosfets and be absolutely sure that both devices are insulated from the heatsinks. Attaching the mosfets directly to the heatsinks will float the heatsinks at high voltage, significantly increasing your risk of shock and injury. Don't try to get away with this because you won't.
Make sure the the heatsinks are not touching any of the traces or other components. Attach the heatsinks to the board by soldering their through pins to the bottom-side pads.
Amplifier Board Assembly Instructions
- Populating the amp boards is straightforward. Follow the same instructions as the PS board leaving out the mosfet step.
- Insert the tubes making sure you get them into the correct sockets.
Do not wire across J1 unless you are having hum or noise problems that cannot be solved by any other changes. See the Troubleshooting section for more information.
Clean up the solder flux residue from the board with isopropyl alcohol (or electronics flux remover) and a brush.
Inspect all solder connections carefully, using a magnifying glass, to make sure there are no solder bridges or cold solder joints. Use a multimeter in ohms scale to check for short circuits. Correct any mistakes before proceeding.