5
The Rear Panel:
17. AC LINE IN: Firmly plug the female end of the supplied
power cord into this socket, pushing it in until it is fully seat-
ed. Plug the male end of the cord into a properly grounded
AC outlet of the correct voltage. DO NOT DEFEAT THE
GROUND PIN OF THE AC PLUG! Use only the supplied
power cord. If the amplifier is to be used outside of the
United States, see your authorized Crate dealer for infor-
mation about alternate line cords and power converters if
needed.
18. FUSE: This fuse protects the amplifier against damages
caused by overload conditions in the unit. If the fuse blows,
replace it only with the same size and type as indicated on
the rear panel. If the fuse blows continually, the line voltage
may be incorrect, or the amp may need servicing.
19. BIAS ADJUST / BIAS TEST POINT: For qualified
Service Personnel only! (All others please just ignore
these internal Bias adjustment potentiometers.)
20. IMPEDANCE SWITCH: For the best performance and
least strain on the amp, you MUST match the amp’s imped-
ance to that of your speaker cabinet(s). Set the selector
switch to the 8 or 16 ohm position, depending on the total
impedance of your cabinets. The chart below can help you
determine that impedance based on the following combi-
nations of speakers connected in parallel.
CAB IMP.
# OF CABS
TOTAL IMP.
16 ohms
2
8 ohms
32 ohms
2
16 ohms
32 ohms
4
8 ohms
21. SPEAKER JACKS: The amplifier is shipped from the fac-
tory with its internal speaker connected to Main speaker
jack. An second cabinet may be connected to the Ext. jack,
as long as the Impedance switch (#20) is properly set. If an
external speaker cabinet is to be without the internal speak-
er, uplug the internal speaker cable from the amplifer and
connect the external speaker to the Main jack. (When
reconnecting the internal speaker, be sure to use the Main
speaker jack!
22. EFFECTS LEVEL CONTROL: Use this knob to set the
input level of the signal from the Effects Loop Return jack
(#23). The Effects Loop Send level is adjusted by the
Master volume controls (#11).
23. EFFECTS LOOP RETURN JACK: Connection from an
external effects device is made via this jack. Connect a
shielded instrument patch cord from the output jack of the
effect to the return jack. The return jack also doubles as a
"power amp in" jack, to feed a line-level signal directly into
the internal power amp. This is useful when "slaving" two
amplifiers together. When using in this mode (slaving),
make sure the front panel Master volume controls are all
the way down (at “0”).
24. EFFECTS LOOP SEND JACK: Connection to an external
effects device is made via this jack. Connect a shielded
instrument patch cord from the send jack to the input jack
of the effect. The send jack also doubles as a "preamp out"
jack, to feed a post-eq signal to a mixing board, recording
console or external amplifier.
NOTE: Effects loop operation is parallel with the signal
path. Mix controls on the effects should be set to 100% (full
wet). If no effects are connected to the Effects Loop, the
Effects Level control (#22) acts as an extra volume boost
which can be activated by the footswitch. For the best sig-
nal to noise ratio when NOT using the effects loop, keep
the Effects Level control (#22) set to “0”.
25. FOOTSWITCH JACK: Connect the supplied two button
footswitch for control of channel switching and the effects
loop on/off. The tip of the jack is for channel switching; the
ring is for effects. When a footswitch is connected here, the
front panel channel select switch is disabled.
VC-6112/6210/6212 Amplifier
