User manual

and music as well as instrument signal. When the feedback control is set to minimum, the
amp will behave with a stronger degree of punch and brightness. When the Feedback control
is set to maximum, the amp will be dampened down to allow a better clarity and less
aggressive tone. The Feedback control can help shape your sound and feel of your sound.
14.Bias. The Bias control can make drastic changes to your amplifier’s sound. This control is
able to make your tubes run “hotter” or “colder.” By allowing the tubes to run colder, the Bias
is effectively cutting-off the tube signal. A strong signal will be needed to break over the cut-off
level on the power tubes. This can act like a noise gate and create a sharp cut-off when notes
are transitioned form “on” to “off.” By setting the Bias to HOT the tubes are on and will
produce sound with the tiniest signal. Using this control can make enormous differences in
the attack and decay of your amp’s response.
15.Indicator Lamp. The Indicator Lamp only lights when there is AC power present at the input
power receptacle. The Indicator Lamp can only light when the power switch is turned “on.” If
the indicator lamp is not lit, either the power switch is turned “off” or there is no power at the
AC receptacle.
16.Standby Switch. When the Standby Switch is switched into the down position it will activate
the high voltage on the plates of the tubes which energize the tubes and amplifier. When
Standby is placed in the “up” position, the high voltage is disengaged and the amp in de-
energized.
17. Power. Power switches the AC power “on” and “off” for the amplifier.
18.AC Input. Plug your AC power cord in this socket. Be sure your power cord is securely
pushed in and firm for good contact. If the power cord is loosely plugged in, you may
experience intermittent power.
19.Mains Fuse. This is the fuse for the power, which is supplied to the entire amplifier. Use
correct fuse if replacement is needed. Contact a qualified service person before changing any
fuses.
20.20 Variac Line Fuse. This fuse is specifically for the Variac transformer. If this fuse needs
replacement, use exact replacements. Consult a qualified service person before changing
any fuse.
21.High Tension Fuse. This fuse is for the high voltage applied to the power tubes. A failure of
one or more of the power tubes will cause this fuse to blow. Refer to a qualified service
person for further attention.
22.Pre Amp Fuse. This fuse is specifically for the high voltage applied to the preamp tubes. If
there is a need to replace this fuse, the pre amp tubes need to be checked and or replaced.
Refer to a qualified service technician for further assistance.
23.Speaker Output Jacks. Plug your speaker cabinet into one or both of these output jacks as
needed. A single 8 ohm cabinet can be plugged into either of the two jacks but only one jack
need be used. If you are running two 16 ohm cabinets, you may connect both cabinets, one
cabinet to each jack for a total of 8 ohms output impedance. Be sure your speaker impedance
switch is selected to 8 ohms. If you have a single 4 ohm cabinet, you may use either one of
the two speaker output jacks for the 4 ohm cabinet. Be sure you have your speaker
impedance output switch selected to 4 ohms if using a 4 ohm cabinet. If two 8 ohm cabinets
are to be used, plug each cabinet into one speaker output jack. The total output impedance
will be 4 ohms. Be sure to select 4 ohms with your speaker impedance selector switch.
NOTE: If using one speaker cabinet, either 4 or 8 ohm, use only one speaker output
Dirty Boy User Manual