8
Controls And Features (Continued)
10 - Master Volume:
This control determines
the overall volume of the amplifier Rotating the
control clockwise will increase volume and
increase the harmonic distortion of the amplified
guitar signal.
11 - Edge:
The Edge control is technically a
variable negative feedback control. Please refer
to the operation notes for a complete
explanation of how to use this control.
12 - Presence:
The presence control adds
high frequencies to the guitar tone. Rotating
the control clockwise increases the tone’s high
frequencies.
13 - Pilot Light:
Illuminated when Power
Switch is moved to the “on” position.
14 - Standby Switch:
When moved to the play
position the amp is ready to play. When in the
“standby” position the tubes remain heated but
no sound passes through the amplifier.
15 - Power Switch:
The power switch allows
the flow of AC voltage from the power source to
the amplifier. Move to the “on” position to
power on the amplifier and to the “off” position
to power it down.
16 - Fuse:
Replace only with a 3A slo-blo
fuse.
Never install a larger fuse than specified.
Failure to install the properly rated fuse could
result in damage to the amplifier.
Fuses
provide a critical safeguard for the amplifier and
a blown fuse could be an indication of a much
bigger problem either with the amplifier or the
power source.
See a service technician if the
amplifier is repeatedly blowing fuses.
17 - Rectifier Selection Switch (Not available
for 67100 or 67100-JC):
Your amplifier has the
ability to operate on either a tube rectifier or
from a solid state rectifier and the Rectifier
Selection Switch determines the mode of
operation. The tube rectifier will be a bit
warmer with a softer feel while the solid state
rectifier will provide the player with a bit more
volume, immediacy, and edge.
The amp must
be in Standby mode before changing the
position of this switch.
18 - Bias Adjust Control:
This control allows
either the end user or a qualified technician to
set the idle current of the power tubes.
Approximately 35ma should be used to set the
bias. Your amplifier may have test jacks
installed that can be used with a multimeter to
set the bias. If available they will either be
located next to the tubes on the bottom of the
chassis or on the back panel. Red jack for
positive lead and black jack for negative lead.
19 - Half Power Switch:
Your amplifier is
capable of reducing output using the Half
Power switch. On the 6750 and the 6750-JC
this is accomplished by running the power
tubes in triode mode. When using this option
on those amplifiers you will need to adjust you
tone controls to approximate the tone at full
power. This is not as much of an issue with the
67100 and the 67100-JC.
Effects Loop
20 - Send:
Connect this jack to the input of your
effects chain.
21 - Bypass:
This switch is a true bypass
switch for the effects chain. When the effects
loop circuitry is engaged there will be a slight
increase in white noise
22 - Return:
Connect the return jack to the
output of your effects chain.
23 - Speaker Impedance Selector:
Position
the selector switch to match the amplifier
speaker load.
24/25
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Main And External Speaker Jacks:
Connect a speaker to either of these jacks.
Both jacks can be used at the same time to
drive multiple cabinets. Do not connect a
combined speaker load less than 4ohms or
greater than 16ohms.
IMPORTANT: A speaker
load must be connected to the amplifier at all
times during amplifier operation.
Failure to do
so will result in output transformer failure very
quickly and will not be covered under warranty.
It is a good practice to get in the habit of
listening for normal amp noise as soon as the
standby switch is moved into the play position.
If no noise is heard the amplifier should be
turned off immediately and the speaker
connections checked.