4
In order to change the tube type the user needs to remove the installed Current Source board, and replace it
with either another board, designed for a particular tube type, or install the 5881 tubes as a direct plug-in.
Only the 5881 tubes can be used directly upon the removal of the 6C19 current source board.
Please consult the factory regarding options for other tube types that may be available in the future.
WARNING:
The following procedure should only be performed by qualified personnel
To change the current source:
1. Turn the unit OFF and wait at least 5 minutes to allow the tubes to cool down and the power
supply charge to dissipate.
2. Remove the six screws holding the current source board.
3. Pull the current source board straight up to disengage its connectors.
4. Install the new current source board making sure its connectors are properly aligned. Board will
be positioned properly when the mounting holes in the circuit board align with the standoffs.
5. Install the six mounting screws.
6. Turn the unit ON.