This is the connection diagram for the menu sent to Eastcote. The
numbered drum sets are on the left and the Diagonal Board letters
on the right. The allocation of menu links to drum sets is chosen
so that the maximum number of drum sets are connected in sequence,
with the minimum number of multiple connection to avoid the use
of commons, a notorious source of bad connections. You will see
that drum sets 1 to 5 can all be connected in series and commons are
required on the input to 1, the join from 3 to 4 and 4 to 5 and also to
join 9, 10 and 8.
So put in the joining links between the connections for drum sets 1 to 5.
Now connect a 26 way lead from the input to 1 to the top set of commons.
Two leads then go from this common, one to socket A at the top of the
diagonal board vertical strip of sockets, the other to the output socket
from drum set 7.
The rest of the wiring connections are then made in a similar manner and
the output indicator plugged to the common between 3 and 4.