RedPlate BlackMagic Operations Guide
4
H.T.Fuse
– This fuse is an extra layer of protection for the output transformer and power
transformer. If this fuse blows it generally indicates an output tube failure. Always replace with
same type and rating 3AG 1 amp fuse.
Bias adjustment and bias test point
– Allows external access for bias adjustment (see bias
procedure in the
Maintenance
section).
LINE OUT
– A line level signal jack derived from the speaker output which contains the whole
tone of the amplifier.
Speaker Jacks
– The MAIN and EXT jacks are wired in parallel. The MAIN jack must be used
first because it has a protection device. ALWAYS HAVE A SPEAKER CONNECTED TO AVOID
PERMANENT AMPLIFIER AND OUTPUT TUBE DAMAGE.
Impedance Selector Ω
- Set this to the total impedance of all attached speakers.
Presence Control
– The presence circuit uses global negative feedback to remove low
frequencies which frees up bandwidth for more midrange and highs. The effect of this control is
altered by the setting of the DEPTH control (See below for details). The control clicks off when
rotated to zero for no presence.
Depth Control
–
Works within the presence circuit to adjust the contour of negative
feedback, higher settings allow more low bass to come through. The control has no effect
when the Presence control is rotated to the bypass position.
SEND and RETURN Jacks
– The send jack connects to the input of an external effects device
and the return jack connects to the output of an external effects device. The return jack interrupts
the signal path so the external effects unit must mix the wet and dry signals.
Footswitch Jack
- This is a standard 180 degree 5 pin DIN jack for footswitch connection. If a
replacement cable is needed, make sure all 5 wires are supported. The pinout is conveniently
located on the rear panel for use with automated switcher conversion boxes.
OTHER FEATURES
The BlackMagic comes complete with a 4 button footswitch and a footswitch cable. The cable
used is a regular MIDI cable and is readily available in any length at most music stores.
FOOTSWITCH
CLEAN
– Light on = Clean Channel, Light off = Lead Channel – the footswitch has no effect if
the Volume control on the Lead channel is pulled out (duplicate function).
LOOP
– (All Channels) Light on = normal operation, Light off = Loop jacks are bypassed,
bypassing all effects in the Loop.
Gain2
– (Lead Channel) Light on = engages the Gain2 control. Light off= Gain2 is deactivated.
MASTER2
– (All Channels) Light on = Master2 Control, Light off = Master1.