26
676
TU B E M I C
CHAN N E L STR I P
Replacing The Tube
INSTRUCTIONS FOR QUALIFIED SERVICE PERSONNEL:
CAUTION!
These servicing instructions are for use by qualified service personnel
only. To reduce the risk of electric shock, do not perform any servicing other than that
contained in the operating instructions unless you are qualified to do so. Refer all
servicing to qualified service personnel. Disconnect mains power before servicing.
The 676 ships with a 12AU7 dual triode vacuum tube. Although other tube types, such as the 12AX7 and 12AT7, will work
in the 676, be aware that they will change the saturation characteristics of the preamp. Various manufacturers make these
types of tubes and each will impart different tonal and sonic qualities. Although the 676 ships with a tube that suits various
applications well, finding the tube which imparts the qualities which best suit your taste can make the 676 an even more
valuable tool.
To change the tube:
1�
Disconnect the power cord from
the 676.
2�
Remove the 8 lid screws as
shown in the illustration to the
right – the 2 center screws in
the front panel require an Allen
(hex) key and all remaining
screws require a Phillips
screwdriver.
3�
Lift the lid straight up and off
the chassis.
4�
With the 676 chassis held
securely, carefully pull the
tube straight up and out of the
socket.
5�
Line up the replacement tube’s
pins with the socket then insert
the tube, being careful to push it
straight in to avoid bending the
pins.
6�
Re-attach the lid, making sure
the lid is properly oriented and
the Allen screws are inserted
into the front panel.