Channel 2
Channel 2 is extremely flexible, with a
flavor that brings to mind the great classic American
tones and textures. You can get some pretty impressive
lead overdrive distortion out of Channel 2, and as a rhy-
thm channel it brings out every subtlety of your playing.
The range of tones can be anywhere from sparkling-
clean to perfect for bluesy rhythm—the kind of sound that has an attitude and gets meaner as you pick harder.
Volume
The Volume knob regulates the preamp’s volume and works with the Master to set the level and dis-
tortion amount. A simple rule of thumb is, the higher the Volume is set, the more distortion you get.
Treble (with Pull Bright switch)
This treble control is similar in operation to the one on Channel 1.
In addition, it has a built-in Pull Bright switch. When pulled out, it adds bright highlights to the tone.
Middle (with Pull Notch switch)
The midrange circuit has a slight notch in the frequency spec-
trum at about 550 Hz, and turning the knob alters the depth of that notch. Its Pull Notch switch shifts the
frequency center of that notch down to about 250 Hz. (For reference, most 1950s tweed amps have their
notch centered at 550 Hz, while classic “blackface” amps have theirs centered at 250 Hz.) Experiment with
this, especially if you’re looking for a uniquely expressive rhythm texture.
Bass
The “chunk” and support that form the backbone of your tone come from this control.
Master (with Pull Ninja switch)
Channel 2 has a special EQ circuit that works in conjunction with
the distortion circuit to sweeten the tone. Therefore, the Master knob’s effect goes beyond loudness control. Try
it with different Volume and Middle settings to adjust the amount of “singing” and “grit.” The Ninja Boost™,
activated by pulling out the Master knob, is a sweet-sounding boost characterized by a more subtle effect on
the harmonics than Channel 1’s Boost control while adding sustain. The Ninja Boost helps to drive the power
amp, and the best description of its influence over the tone is that it thickens it.
Reverb
In the tradition of classic amps, your Hundred Duo Twelve is equipped
with a spring reverb. Its single-knob operation controls its effect on the signal com-
ing from both preamp channels. Specially buffered circuitry drives the reverb, keep-
ing your tone intact and minimizing harshness.
Presence
The Presence control is incorporated as a vital part of the power amp sec-
tion. Think of it as a final brightness control after all the EQ, distortion, effects, and reverb.
Standby
By turning the Power on and the Standby off (the down position, labeled with a
“0”), you can warm up the amplifier before applying full voltage to the preamp and power
output tubes. This prolongs tube life. Using the Standby switch when you’re taking a break
also helps to extend the tubes’ life, plus it keeps the amp constantly at the ready. Just flip the
Standby switch to the up (“I”) position, and you’re ready to play.
Power
This is your main power switch. The on position is indicated by the light being illuminated. The off
position is marked by the “0” on the switch. Before turning the amp on, always check that a speaker is con-
nected and that the power cord is firmly plugged into the amp and the outlet.
9
8
7
6
Channel 2
Channel 1
Hundred
Duo Twelve
PULL
SELECT
PULL
BOOST
STANDBY
POWER
LOW
GAIN
HIGH
GAIN
VOLUME
BASS
MIDDLE
TREBLE
MASTER
VOLUME
TREBLE
MIDDLE
BASS
MASTER
REVERB
PRESENCE
HANDCRAFTED BY RIVERA RESEARCH & DEVELOPMENT
SUN VALLEY, CA USA
INPUTS
PULL
BRIGHT
PULL
NOTCH
PULL
NINJA
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
Channel 2
VOLUME
TREBLE
MIDDLE
BASS
MASTER
PULL
BRIGHT
PULL
NOTCH
PULL
NINJA
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
REVERB
PRESENCE
10
9
8
76
5
4
3
2 1
10
9
8
76
5
4
3
2 1
STANDBY
POWER
