Tube Position - Jadis Orchestra reference Owner's Manual

First of all, remove the grid which protects the tube sockets (be sure
the mains connector is unplugged).
Warning: For mounting the tubes, do not force them, this may
damage the sockets. Be careful at dressing power tubes because they have stop
pins on the central parts of the mounting base. Every tube replacement causes an
in-built adjustment modification that must be made by a skilled technician. You
must use tubes that
Mount first the two driver tubes then mount the power tubes . The
tubes placement is shown at the top of this page.
Replace the grid and never remove it when the amplifier is
connected to the mains voltage, whether it is running or not.

Tube position

provide from your distributor.