Technical information

STEP 6: Installing the output tube sockets
Locate (4) MICALEX OCTAL SOCKETS, (4) TUBE RETAINERS (EL34 OR 6550 size depending on your
output tube type), (4) 2 HOLE GROUND LUG AND (8) # 6 – 3/8” machine screw and Nyloc nut.
Install each of the four tube sockets and retainers referencing the pictures for orientation and location
of ground lugs.
The Micalex sockets install from the inside of the chassis
and the tube retainers on the outside. Each of the socket
assemblies is identical.
Install each socket with the locator notch (between socket
pins 1 and 8) pointing towards the rear of the chassis.
Also install a ground lug on the mounting screw nearest
the rear of the chassis on each socket.
Secure the tube retainers, sockets and ground lugs to the
chassis using a Philips screwdriver, 5/16” nut driver and
this hardware sequence:
SCREW – RETAINER – CHASSIS – (GROUND LUG) – NUT
TECH NOTE: the ground lug on the socket mounting screw is a critical
connection. This is the ground reference for the output tube plate, grid
and screen grid. If this connection is loose or intermittent it will cause
instability in the amp. Be certain that the Nyloc nut is fully tightened
and the socket rests flush on the chassis.
Assure that the tube retainer mounting tabs are oriented as pictured.
You’ll want the maximum amount of space between the socket and the
retainers, especially if you are using 6550 output tubes. The base of this
tube is larger in diameter than the tube socket and they may not fit
securely if partially blocked by the retainer mounting tabs.