Rivera KNUCKLE HEAD 2 User manual

OWNER’S MANUAL
K NUCKLE H EAD
®
II

Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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PACKING INFORMATION
Unpacking
Before you plug in, inspect your KnuckleHead II amp for any damage. Your amp was inspected and
sound-tested before shipment, but transportation can sometimes be tough. Check that the FS-7
Footswitch and power cord have been shipped with the amp. If parts are missing, or if any damage has
occurred, contact your dealer.
Packing Materials
We designed the original box and packing materials to protect your amp during shipment. Save them. If you ever
need to send your amp to us or to anyone else, the original box and packing materials will ensure safe transit.
SAFETY PRECAUTIONS
Throughout this manual, the lightning flash with an arrowhead symbol within a triangle is intended to
alert you to the presence of uninsulated “dangerous voltages” within the product’s enclosure that may be
of sufficient magnitude to constitute a risk of electric shock to persons.
The exclamation point within a triangle is intended to alert the user to the presence of
important operating and maintenance (servicing) instructions in the literature that accompa-
nies the product. There are no user-serviceable parts inside of this amplifier.
Warning: To avoid the risk of shock or fire, do not expose this amplifier to moisture. Do
not remove the chassis from its cabinet, or remove metal covers from chassis parts. Removing
the chassis from its cabinet exposes extremely dangerous high voltages.There are no user-serv-
iceable parts inside. Hazardous voltages are present inside the chassis. Refer all servicing to
qualified personnel.
Caution:To avoid a fire hazard, always replace the fuses with the same type and rating.
Caution: Always replace the line cord (mains supply) with the proper type.
Caution: Always turn off the amplifier before making or unplugging any speaker connections.
Always transport your amplifier securely, preferably in a suitable flight case or packing carton. Before operat-
ing your amplifier, be sure the speakers used are properly connected. For countries where 220 to 240 volts
AC is encountered, make sure that you have the correct power cord. Our 230-volt export unit can be used
with any of these voltages. For Japan 100VAC models, all instructions for the 115VAC models apply.
In the event that you have questions, comments, or suggestions, please contact us at:
Rivera Research & Development
13310 Ralston Ave., Sylmar, CA 91342 USA
Phone: [phone] • Fax: [phone]
Email: [email protected] • http://www.rivera.com
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Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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TABLE OF CONTENTS
Packing information .......................................................................................................... 1
Safety precautions ..............................................................................................................1
Warranty ............................................................................................................................ 4
Quick Start instructions...................................................................................................... 5
Front panel ........................................................................................................................ 6
Power ............................................................................................................................ 6
Standby ........................................................................................................................ 6
Presence..........................................................................................................................6
Focus..............................................................................................................................6
Clean/Rhythm channel overview and controls ..............................................................6
Lead/Crunch channel overview and controls..................................................................7
High Gain input ............................................................................................................8
Low Gain input..............................................................................................................8
Rear Panel............................................................................................................................8
Mains Input ..................................................................................................................8
Mains Fuse ....................................................................................................................8
HT Fuse ........................................................................................................................9
Speaker outputs..............................................................................................................9
Line Out ........................................................................................................................9
Impedance Selector ......................................................................................................10
Footswitch jack ............................................................................................................10
Effects Loop ................................................................................................................10
Setting Effects Loop levels..................................................................................................11
Connecting the KnuckleHead II with other gear ..............................................................12
Driving an extension speaker cabinet............................................................................12
Driving two speaker cabinets........................................................................................13
Running two amps in parallel without a Y-cord ..........................................................13
Slaving a second KnuckleHead II ................................................................................14
Placing a signal processor in the KnuckleHead II’s effects loop ....................................15
Sending a direct signal to a P.A. or recording gear........................................................15
Connecting a KnuckleHead II to a Sub 1 subwoofer....................................................16
Care and troubleshooting ..................................................................................................17
Quick troubleshooting guide ............................................................................................18
Tube care and replacement ................................................................................................19
Tube location chart ......................................................................................................19
Tube function explanation............................................................................................19
Checking for microphonic tubes..................................................................................19
Preamp tube first aid..........................................................................................................20
Power amp tube first aid....................................................................................................20
Tube types by manufacturers..............................................................................................21
Biasing your KnuckleHead II ............................................................................................21
Specifications ....................................................................................................................22

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Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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YOUR RIVERA AMP ISANIMPORTANT PART
OFYOUR SOUND
Your sound is your signature, your mark, your voice. An amp only deserves to have your guitar plugged
into it if it can deliver the tone you want—and, of course, the dependability you need. It’s as simple as
that. And it’s exactly why you bought your RIVERA amp. For that, we thank you, and we’re confident
that you’ll enjoy your amp for years to come.
Many factors go into creating a great amp—experience, an understanding of what guitarists want, and a
lot of hard work. You’ll notice that tone isn’t on any parts list. Roadworthiness isn’t, either. And there’s
no law saying that an amp must sound good or be well-made. But we dedicate ourselves to making the
best-sounding, most reliable amplifiers anywhere.That’s why we use only the highest-quality compo-
nents, regardless of price. Such features as metal jacks, ultra-strong dadoed cabinet construction, and
highest-quality electronic components are part of our uncompromising approach.They’re chosen for
their precision, strength, and ability to withstand the rigors of years of use—and occasional abuse—on
the stage and in the studio. No compromises are made because cutting any corners—no matter how
small—means settling for second best.
This requires dedication to you, the guitarist, and a belief that an amp is more than a collection of parts. It’s
part of your sound.
Please fill in the following information for future reference:
Model Name: KnuckleHead II
Model Number: K-2100
Serial Number:
Dealer’s Name:
Dealer’s Address:
Date of Purchase:
13310 Ralston Ave.,
Sylmar, CA 91342 USA
Phone: [phone]
Fax: [phone]
Email: [email protected]
http://www.rivera.com

WARRANTY
Subject to the Obligations and Exclusions found below, this RIVERA product is warranted against manufac-
turing defects in material and workmanship for the period of one (1) year from the date of purchase, with
the exception of tubes, which carry no warranty, and loudspeaker drivers, which are covered for 90 days.
The warranty period commences on the date of purchase by the original user. Performance under this warranty
must be obtained at one of the following: a RIVERA Authorized Service Station, by returning the unit to the
RIVERA factory with prior authorization, or (in countries outside of the United States) by a representative
RIVERA distributor. A list of RIVERA Authorized Service Stations can be obtained from RIVERA, 13310
Ralston Ave., Sylmar, CA 91342, USA, ATTN: Warranty Service.Telephone [phone]; telefacsimile
[phone].
Obligations
1.This warranty will be honored only on the presentation of the original proof of purchase.
2.Transportation of the product to the service station or RIVERA factory is the responsibility of the user
unless specifically stated otherwise in this warranty. RIVERA will pay for return shipping charges if the
repairs are covered by the warranty.
Exclusions
1.This warranty shall not cover adjustment of customer-operated controls as explained in the appropriate
model’s instruction manual, or products that have been altered, replaced, or have missing serial numbers.
2.This warranty shall not apply to the appearance of accessory items including, but not limited to, cabinets,
cabinet parts, or knobs.
3.This warranty does not apply to uncrating, setup, installation, or the removal and reinstallation of products for repair.
4.This warranty shall not apply to repairs or replacements necessitated by any cause beyond the control of
RIVERA including, but not limited to, any malfunction, defects, or failure caused by or resulting from
unauthorized service or parts, damage resulting from improper packaging when returning product, dam-
aged or broken tubes, incorrect line voltage, improper maintenance, modification or repair for the user,
abuse, misuse, neglect, accident, fire, flood, or other Acts of God.
5.This warranty shall not apply to any loudspeaker drivers that have been damaged due to thermal destruc-
tion, or physical destruction such as moisture, rips, tears, shock, or transport.
6. Responsibility for any repair of any RIVERA product sold outside of U.S. boundaries is borne by the RIVERA
representative in that particular country or territory. Also, the warranty term and conditions may be different from
those stated above. Please contact the RIVERA distributor or dealer in your country for more information.
The foregoing is in lieu of all other expressed warranties, and RIVERA does not authorize any party to
assume for it any other obligation or liability. In no event shall RIVERA be liable for special or consequential
damages arising from the use of this product, or for any delay in the performance or this warranty due
to causes beyond our control. Some states do not allow limitations on how long an implied warranty
lasts and/or do not allow the exclusion or limitation of consequential damages, so the above limitations
on implied warranty and consequential damages may not apply to you. This warranty gives you specific
legal rights. You may have other rights that vary from state to state.
© 2003 Rivera Research & Development. All rights reserved.
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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NOTIME TOREAD THIS MANUAL?
ATLEAST READ THIS PAGE NOW!
Before you plug in:
Take a quick look inside the back of your amp. Make sure of the following—
1. The tubes are securely seated in their sockets (see page 19 for further information on checking for loose
tubes).
2. The internal speaker’s cord is plugged into the Speaker 1 output (this jack must always be used first).
3. The power cord is plugged in.
4. The FS-7 footswitch is plugged in (this is optional).
Now look at the front to make sure:
1. The Gain and Master controls are set at low levels (2 is a good starting point).
2. The Power switch is off (the lower half is pushed in).
3. The Standby switch is set to standby mode (the lower half is pushed in).
Plug in!
Now plug the amp into the wall, plug your guitar into either input jack, and set your controls to one of the
Quick Start settings outlined here. Then turn on the Power switch. Wait for about a minute for the tubes to
warm up. Turn on the Standby switch. Now it’s time to rock.
After you’ve played with your KnuckleHead II for a while, check out the rest of the manual for some good tips
on getting the most out of your amp.
QUICK START SETTINGS
If you’re looking for a good starting point, try these settings. Remember that every guitar sounds different, so
try both inputs, and adjust the reverb and presence to suit your taste.
Lead: Massive Rectified
Clean: Strat Rhythm
Lead: Munky Grind
Clean: Studio Clean
Lead: Eighties Rock
Clean: Fat Blues Lead
PRESENCE FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10 5 3 7 3
PULL
7 7 561410
PULL PULL PULL
Use
Either
PRESENCE FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10 5 3 8 4
PULL PULL
77 58198
PULL PULL PULL
Use
Either
PRESENCE FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
443-6 6 9
PULL
7-9 4-7 57576-7
PULL PULL
Use
Either
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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FRONT PANEL
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 connected and that the power
cord is firmly plugged into the amp and the outlet.
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.
Presence The Presence control is incorporated as a vital part of the power amp
section.Think of it as a final brightness control after all the EQ, distortion, and
effects.
Focus This control is a RIVERA exclusive that actually lets you change the speaker’s response charac-
teristics, from tight to loose. The effect can give closed-back cabinets a sound more akin to an open one,
and vice-versa, plus you can “custom blend” the amount of hardness your final sound has.
Clean/Rhythm channel The Clean/Rhythm channel is extremely flexible, with a flavor that brings
to mind the great classic American tones and textures. You can get some impressive lead overdrive dis-
tortion out of the Clean/Rhythm channel, and as a rhythm 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.
Master 2 (with Pull Ninja switch) The Clean/Rhythm channel has a special EQ circuit that works
in conjunction with the distortion circuit to sweeten the tone.
Therefore, Master 2’s effect goes beyond loudness control.Try
it with different Gain 2 and Middle settings to adjust the
amount of “singing” and “grit.”The Ninja Boost, activated by
pulling out the Master 2 knob, is a sweet-sounding boost
characterized by a more subtle effect on the harmonics than
the Lead/Crunch channel’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
Bass The “chunk” and support that form the backbone of your tone come from this control.
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.
MASTER 2 BASS MIDDLE TREBLE GAIN 2
NINJA NOTCH BRIGHT
PULLPULLPULL
CLEAN/RHYTHM
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Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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POWER STANDBY
PRESENCE FOCUS
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Treble (with Pull Bright switch) This treble control is similar in operation to the one on the
Leac/Crunch channel. In addition, it has a built-in Pull Bright switch. When pulled out, it adds bright
highlights to the tone.
Gain 2 The Gain 2 knob regulates the preamp’s volume and works with Master 2 to set the level and dis-
tortion amount. A simple rule of thumb is, the higher Gain 2 is set, the more distortion you get.
Lead/Crunch channel Both channels are voiced differ-
ently, and the Lead/Crunch channel is definitely geared
toward creating impressive overdrive (think of a “distor-
tion” tone). Grit, grunge, dirt—whatever you’re looking for
in the distortion department is here, from sweet and
singing to hard-driving to maximum sustain.
Note: Like the controls on all classic amps, the Bass, Middle, and Treble interact, creating smooth,
musical tone changes. All three controls operate with even response throughout their ranges.
Master 1 (with Pull Boost switch) Think of Master 1 as a sort of governor that sets the maxi-
mum loudness for the channel. Also, think of it as the second half of what Gain 1 does. With Gain 1
turned down and Master 1 up, there’s less distortion than if you crank up Gain 1 and set Master 1 lower.
The Master 1 control comes after all distortion and tone-shaping on the Lead/Crunch channel, so its level
doesn’t have a bearing on your basic tone. When you pull out the Boost switch on the Lead/Crunch chan-
nel, it adds a whole range of harmonics, and not just gain. This is easy to hear by playing a power chord
and comparing its sound with the switch pushed in and pulled out. With the switch activated, the tone
blooms, going from fat to ferocious
.
Treble (with Pull Sweet) Whether you’re looking for edge, slash, or just a little shimmer, this knob’s
for you. Like the Bass control, the apparent effect of theTreble changes with the loudness and distortion
you dial in.The Pull Sweet switch increases the high-end brightness post-distortion, adding an addition-
al distortion edge
.
Middle (with Pull Scoop) The midrange circuit provides the “meat” that fills out your sound. It
has a slight notch in the frequency spectrum at about 500 Hz when the control is pushed in, and 750 Hz
when the control is pulled out. Turning the knob alters the depth of that notch, letting you dramatically
change the overall voicing of your tone.
Bass (with Pull Bottom) The “chunk” and support that form the backbone of your tone come from
this control. Its effect on your overall sound will be different at high and low volumes due to the speak-
er’s characteristics and how much distortion you use. Pull Bottom extends the bass and bottom-end range.
This is essential for adding the huge wall of bottom end that modern players need, especially with 7-
String instruments. The bass EQ curve has been specially tailored to complement the maximum bass
response of the RIVERA K-Cab speaker enclosure.
Gain 1 (with Pull Channel Select switch) Although it’s labeled “Gain,” this control does a lot
more than determine how loud the Lead/Crunch channel is. It regulates the preamp’s volume and works
with Master 1 to set the level and distortion amount. A simple rule of thumb is, the higher Gain 1 is set,
the more distortion you get. The pull switch selects which channel is active. Its circuitry is designed so
that you don’t hear a pop or click when the channel is changed. (The FS-7 footswitch also selects chan-
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
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8
MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECT
PULL
LEAD/CRUNCH
PULL PULL PULL PULL
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nels; Gain 1’s pull switch must be pushed in for the FS-7 to choose channels. See info on the FS-7 and
its functions.)
Low Gain input This is a low-sensitivity input. Guitars plugged into it have
more headroom before distortion sets in (meaning that you can crank up a chan-
nel’s volume a little louder before you experience preamp distortion). This is a
good choice for a clean overall sound, and is especially well-suited to active pick-
ups or guitars equipped with preamps.
High Gain input This is a high-sensitivity input. If your guitar has hot pickups, then plugging into
it makes it easy to overdrive the preamp section, creating harmonic distortion. Guitars equipped with
low-output pickups seem hotter than usual when plugged into this input.
REAR PANEL
Mains Input
Your KnuckleHead II has a detachable power cord that connects to the chassis AC connector labeled
Mains Input. Always use this cord and, in the event that the power cord requires replacement, replace it
with the same type of power cord. Consult your RIVERA dealer for further information. Be sure to use
a grounded electrical mains power supply socket whenever possible. These outlets have a grounding pin
in addition to the nor-
mal line and neutral
pin. The power cord
supplied with your
KnuckleHead II has a
3-pin plug. Do not cut
off or damage the
ground pin. If the
available electrical outlet is of the older 2-pin type, use a suitable ground-lift adapter.
The U.S.A., Canada, and Japan share a common CSA/UL-style cord. Most of Europe and Scandinavia
utilize a Euro plug and have a SEMKO/VDE-style cord. Australia uses a different type of plug, as does
England.
Note: Avoid using long extension cords. Long cords have sufficient resistance to electrical current that the
voltage arriving at your amp can be significantly reduced.This can have a bad effect on your tone.
Mains Fuse
ThisAClinefuseprotectsyouramplifier from damage duetoshorts, momentary surges,anddefectivepowertubes.
In the event of a fuse failure, always replace it with the same type of fuse.
Note: Always turn the amp off and wait about five minutes before replacing a fuse. This allows the
parts to cool and high voltages to dissipate.
For 100VAC versions, the Mains Fuse is: 5 Amp, 250Volt Slo-Blo type (size 3AG, or MDL)
For 115VAC versions, the Mains Fuse is: 4 Amp, 250Volt Slo-Blo type (size 3AG, or MDL)
For 230VAC versions, the Mains Fuse is:T 2A (time-delay, 5mm x 20mm size)
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
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H.T.
FUSE MAINS FUSE
1A 250V
SLO-BLO 4A 250V SLO-BLO 115V 60Hz
FUSE
FUSE
CAUTION
TO REDUCE THE RISK OF ELECTRIC
SHOCK, DO NOT REMOVE CHASSIS.
REPLACE FUSE WITH SAME TYPE AND RATING.
UTILISER UN FUSIBLE DE RECHANGE DE MEME TYPE.
INPUT POWER
440 WATTS
MAINS INPUT
MODEL
KNUCKLEHEAD II
SERIAL NUMBER !
RIVERA RESEARCH & DEVELOPMENT CORP., SYLMAR, CALIFORNIA, USA
AVIS: RIRQUE DE CHOC ELECTRIQUE NE PAS OUVRIR
LOW
GAIN HIGH GAIN
1
9
8
7
6

HT Fuse
The power amplifier circuit has its own fuse for protecting the output section from short circuits and
transient current peaks that exceed the normal current draw. These conditions are usually caused by a
bad tube. When a short circuit or transient peak causes the fuse to blow, the output tubes should be
checked and replaced, if necessary.
For 100VAC and 115VAC versions, the HT Fuse is: 1 Amp, 250 Volt Slo-Blo type (3AG, or MDL)
For 230VAC versions, the HT Fuse is: T1A (time-delay, 5mm x 20mm size)
Repeated blowing of this fuse is a clear indicator of a defective output tube. Always use the
correct fuse value when replacing the HT Fuse.
If the Mains Fuse or the HT Fuse repeatedly blows, refer your amp to your local RIVERA dealer or
contact us at [phone] for further service assistance.
Speaker outputs
A speaker must always be connected to your
KnuckleHead II. The amp is designed to deliver at
least 120 watts to a 4-ohm speaker load. If it has to
drive speaker loads lower than 2 ohms, its output
transformer or other components could be damaged.
You can use 8- or 16-ohm extension cabinets, either
alone or in pairs (one connected to each speaker out-
put).
Never use a 2-ohm speaker cabinet alone, or a pair of 4-ohm extension speaker cabinets together. The
only time you may run the amp without a speaker connected is if you have a proper “dummy” imped-
ance load box plugged into the speaker output. Using a dummy load protects the output transformer,
but prolonged use shortens the life of the amp’s output tubes.
Always use a heavy-gauge speaker cord. A shielded guitar cord can’t handle the power that
your amp provides, and therefore won’t sound right—plus it may actually harm your amp.
Refer to the connection diagrams for further information.
Note: Never use a speaker output to connect directly to the input of a mixer, a tape recorder, a slave
amp, or headphones. For further information, refer to the hook-up diagrams for proper connection
with extension speaker cabinets.
Line Out
Your KnuckleHead II can drive another KnuckleHead II, power amp, or other guitar amplifier. The
Line Out is post-power amp, so every bit of tone from your preamp, effects (if used), and power-amp
circuitry is sent from this jack. Use a shielded cord connected between the KnuckleHead II’s Line Out
and the input of a second amplifier (check that amp’s manual—it may recommend a specific input).
The Line Out can also be used to feed a signal to a tape recorder or mixer. Although the recorder or mixer
doesn’t receive the tone that comes from the speaker, it does receive all of the signal from every other stage of
the amp, and for live-performance recording, it does an excellent job of isolating your guitar sound.
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
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8
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3
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1
8
8
WARNING: TO REDUCE THE RISK OF FIRE
OR ELECTRIC SHOCK, DO NOT EXPOSE
THIS EQUIPMENT TO RAIN OR MOISTURE
TOTAL MIN. z 4 Ω120W. RMS
SPEAKER JACKS IN PARALLEL
LINE OUT
560 Ω
SPEAKER 2
FOOTSWITCH
USE FS-7 ONLY
IMPEDANCE
SELECTOR K
N
S
E
SPEAKER 1
USE FIRST
RIVERA
R
AVIS: RI
R
8
4
16
10
9
8
7

Note: Do not connect the Line Out to speakers or headphones. For further information, refer to the
hook-up diagrams for proper connection.
Impedance Selector
Set the Impedance Selector to match the impedance load of your cabinets. Here’s how:
4-ohm setting = One 4-ohm cabinet or two 8-ohm cabinets (one connected to each speaker output)
8-ohm setting = One 8-ohm cabinet or two 16-ohm cabinets (one connected to each speaker output)
16-ohm setting = One 16-ohm cabinet connected to the Speaker 1 jack
Note: Loads less than 4 ohms may harm your amp. If you aren’t sure if your speaker load is correct,
contact your RIVERA dealer, or call RIVERA Customer Service.
Footswitch jack
This 8-pin DIN plug is designed to work
specifically with the included FS-7 foot-
switch. Your KnuckleHead will function
perfectly without a footswitch. However,
the footswitch provides a hands-free way
to switch channels and select boost functions. Its three switches control the following:
Channel Select Gain Boost for Lead/Crunch Channel Ninja Boost for Clean/Rhythm Channel
Note: If you are using the FS-7 footswitch, make sure that all pull switches on the amp’s front panel are
pushed in. If any of the pull switches is pulled out, then the corresponding footswitch function will not
operate. Also, the switches and their LEDs are driven by the amplifier’s power. There is no battery to
replace inside the FS-7.
Effects Loop
Of course, you can use pedals and rack-mounted effects between your guitar and the amp. In fact,
that’s where most wah-wahs and other pedals sound exceptionally good. However, rack signal proces-
sors are often best suited to being placed after the preamp’s tone-shaping circuitry. Your KnuckleHead
II’s Effects Loop is designed to give you the best match between the amp and the processor by allowing
you to set the level of the signal going to the effect, as well as the one coming back. Therefore, you can
tailor your amp/effects levels for best signal-to-noise ratio and the amount of distortion you want.
Note: The Effects Loop Send can be used to route a signal to a guitar tuner.
The Effects Loop comes after the preamp section. In addition, its low-impedance circuitry lets you
drive everything from the simplest stomp-box effect to the most sophisticated pro signal processor with
excellent results. It’s also fully buffered, meaning that it can drive long cords and line-level gear and
mixing consoles. (Because the signal is electrically unbalanced, you can use an unbalanced-to-balanced
output transformer to connect to equipment requiring a balanced input.)
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
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4
3
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8
FOOTSWITCH
USE FS-7 ONLYCAUTION: CHASSIS SURFACE HOT.
ATTENTION: SUPERFICIE DE CHASSI CHAUDE
CAUTION: NO USER
SERVICEABLE PARTS INSIDE.
REFER SERVICING
TO QUALIFIED PERSONNEL.
SEND
LEVEL RETURN LEVEL
EFFECTS LOOP
z OUT
560 Ωz IN 250k Ω
SEND RETURN
10
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Setting Effects Loop levels
1. After you connect the amp’s Send and Return with the signal processor’s input and output, set the
amp’s Send Level and Return Level between 1 and 2.
2. Plug in your guitar, turn on the signal processor, and then turn on the amp (or flip the standby switch).
3. Set the amp’s Effects Loop Send Level and the
signal processor’s input level so that you don’t over-
load the processor. Keep your ears open for
unwanted distortion from the signal processor
(you’ll know it by its crackly, unmusical sound).
Whack a few chords on your guitar to check that
your settings are correct.
4. Now turn up the Effects Loop Return knob until the proper volume and overdrive are dialed in.
You’ll probably have to experiment with the signal processor’s output level until you get the best sound
and lowest amount of noise.
5. Make sure that you set your straight/effects blend at the signal processor, since all of your preamp’s
signal is passed through the Effects Loop. Do not use an effects-only output to return from the proces-
sor to the amp. Always use the “mix” output, if the unit has one.
The Effects Loop Send is configured so that it is always active, so you can use it as a variable output.
Note: If you use the Send to drive slave amps, etc., and have nothing plugged into the Return jack, the
signal still passes from the preamp to the power amp.
CAUTION: CHASSIS SURFACE HOT.
ATTENTION: SUPERFICIE DE CHASSI CHAUDE
CAUTION: NO USER
SERVICEABLE PARTS INSIDE.
REFER SERVICING
TO QUALIFIED PERSONNEL.
SEND
LEVEL RETURN LEVEL
EFFECTS LOOP
z OUT
560 Ωz IN 250k Ω
SEND RETURN
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
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9
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1
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1
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1
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8
1
12
11
10

1
13
12
11
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
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4
3
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6
5
4
3
2
1
8
8
CONNECTING THE
KNUCKLEHEAD II
WITH OTHER GEAR
The following illustrations will help you to properly connect your KnuckleHead II to other amps,
extension speaker cabinets, and recording and P.A. gear. Make sure the amp and all other gear are
turned off whenever you make or change any connections.
Using a heavy-gauge speaker cord, connect the output jack labeled Speaker 1 to the speaker input on
an extension cabinet with a minimum of a 4-ohm impedance and power-handling capacity of at least
120 watts for the KnuckleHead II. A single 8- or 16-ohm extension cabinet can be used, too. For the
best tone and maximum output, we recommend using a RIVERA K412 or K212 speaker cabinet.
Note: Regardless of the type or number of speaker cabinets you use, always make sure that the
KnuckleHead II’s Impedance Selector is set to match the speaker cabinet’s impedance.
4
8
16
TOTAL MIN. z 4 Ω120W. RMS
SPEAKER JACKS IN PARALLEL
Knuckle
H
eadII
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
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3
2
1
10
9
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3
2
1
10
9
8
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1
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8
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2
1
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9
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2
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1
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2
1
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9
8
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5
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3
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9
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4
3
2
1
10
9
8
7
6
5
4
3
2
1
LINE OUT
560 Ω
SPEAKER 2 SPEAKER 1
USE FIRST
IMPEDANCE
SELECTOR SPEAKER
Driving an extension speaker cabinet

1
14
13
12
1
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
10
9
7
6
5
4
3
2
1
10
9
7
6
5
4
3
2
1
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
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9
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1
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9
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1
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6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
8
8
4
8
16
TOTAL MIN. z 4 Ω120W. RMS
SPEAKER JACKS IN PARALLEL
Knuckle
H
eadII
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
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3
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1
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3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
LINE OUT
560 Ω
SPEAKER 2 SPEAKER 1
USE FIRST
IMPEDANCE
SELECTOR SPEAKERSPEAKER
Driving two speaker cabinets
In this configuration, the KnuckleHead II is driving two speaker cabinets with identical impedances. Using heavy-
gauge speaker cords, connect the output jacks labeled Speaker 1 and Speaker 2 to the speaker inputs on extension
cabinets with a minimum 8-ohm impedance and power-handling capacity of 120 watts for the KnuckleHead II.
You can also hook up two 16-ohm cabinets, but never use two 4-ohm cabinets, because the overall impedance
load will be too low for the amplifier and could result in damage. When using two 8-ohm cabinets, set the
KnuckleHead II’s Impedance Selector to 4 ohms.When using two 16-ohm cabinets, set it to 8 ohms.
Running two amps in parallel without a Y-cord
INPUTS
HIGH
GAIN
INPUTS
LOW
GAIN
HIGH
GAIN
LOW
GAIN
Knuckle
H
eadII
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
Knuckle
H
eadII
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
The preamp and output amp sections, as well as all controls, function normally in this setup. Use a
shielded cord. Note: Make sure speaker cabinets are connected to both KnuckleHead IIs.
From
Guitar

1
15
14
13
2
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
10
9
7
6
5
4
3
2
1
10
9
7
6
5
4
3
2
1
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
8
8
SEND
LEVEL RETURN
EFFECTS LOOP
10
9
8
7
6
5
4
3
2
1
RETURN
LEVEL
SEND
Z IN
250K Ω
Z OUT
560 Ω
10
9
8
7
6
5
4
3
2
1
Knuckle
H
ead
II
®
PRESENCE
POWER STANDBY FOCUS MASTER2 BASS MIDDLE TREBLE GAIN2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN
HIGH
GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR,CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
Knuckle
H
ead
II
®
PRESENCE
POWER STANDBY FOCUS MASTER2 BASS MIDDLE TREBLE GAIN2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN
HIGH
GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR,CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
TOTAL MIN. z 4 Ω120W. RMS
SPEAKER JACKS IN PARALLEL
LINE OUT
560 Ω
SPEAKER 2 SPEAKER 1
USE FIRST
TO SPEAKER CABINET
Slaving a second KnuckleHead II
Slaving a second amp or power amp
POWER AMP
IN
Knuckle
Head
II
®
PRESENCE
POWER STANDBY FOCUS MASTER2 BASS MIDDLE TREBLE GAIN2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN
HIGH
GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR,CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
Knuckle
H
ead
II
®
PRESENCE
POWER STANDBY FOCUS MASTER2 BASS MIDDLE TREBLE GAIN2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN
HIGH
GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR,CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
TOTAL MIN. z 4 Ω120W. RMS
SPEAKER JACKS IN PARALLEL
LINE OUT
560 Ω
SPEAKER 2 SPEAKER 1
USE FIRST
TO SPEAKER CABINET
Using a shielded cord, connect the first KnuckleHead II’s Line Out to the Effects Loop Return jack on a sec-
ond KnuckleHead. Adjusting the Return Level sets the relative volume of the second amp. All tone and dis-
tortion adjustments are made by the first amp. Alternatively, you can use the Effects Loop Send jack from the
first amp instead of its Line Out.The Send Level control sets the signal level being sent to the second amp.
Note: Make sure that at least one speaker cabinet is connected to each amp at all times.
Connect a shielded cord from your KnuckleHead II’s Line Out to the Power Amp In or Effects Loop Return
of a second amp. All volume and tone changes made on the KnuckleHead II will affect what comes out of the
second amp. Caution: Never use the speaker outputs as line outputs. Their power level is extremely high and
can cause tremendous damage to another amp’s input. If you don’t have any effects patched into the
KnuckleHead II’s Effects Loop, you can use its Send jack instead of the Line Out.The Send Level knob then
acts as a variable output level.

1
16
15
14
3
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
10
9
7
6
5
4
3
2
1
10
9
7
6
5
4
3
2
1
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
8
8
Using shielded cords, connect the Effects Loop Send to the processor’s input, and the processor’s output to the Effects
Loop Return. Adjust the mixture of effect/non-effect sounds at the signal processor, and set the levels at the amp and
processor for lowest distortion. If you use multiple signal processors, connect them in series (processor 1’s output to
processor 2’s input, etc.), and patch the KnuckleHead II’s Send to the first processor’s input and the KnuckleHead II’s
Return to the last processor’s output. If the processor has stereo outputs, you can connect one to the Effects Loop
Return of a second amp.
Placing a signal processor in the effects loop
SEND
LEVEL RETURN
EFFECTS LOOP
10
9
8
7
6
5
4
3
2
1
RETURN
LEVEL
SEND
Z IN
250K Ω
Z OUT
560 Ω
10
9
8
7
6
5
4
3
2
1
INPUT
OUTPUT
Knuckle
H
eadII
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
Sending a direct signal to P.A. or recording gear
LINE INPUT
Knuckle
H
eadII
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
TOTAL MIN. z 4 Ω120W. RMS
SPEAKER JACKS IN PARALLEL
LINE OUT
560 Ω
SPEAKER 2 SPEAKER 1
USE FIRST
TO SPEAKER CABINET
SIGNAL
PROCESSOR
Using a shielded cord, connect the KnuckleHead II’s Line Out to the line input or channel input of a
mixer or recorder. (The signal comes from the amp’s output stage, so all tone, distortion, and overdrive
characteristics are included.) You can use the Effects Loop Send jack instead of the Line Out, too.
Caution: Never use the speaker output.

1
17
16
15
4
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
10
9
7
6
5
4
3
2
1
10
9
7
6
5
4
3
2
1
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
8
8
Knuckle
H
ead II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTEDBY
RIVERARESEARCH& DEVELOPMENTSYLMAR, CAUSA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
NORMAL
INVERTED
HIGH PASS
EFFECT LOOP
FULL RANGE
0˚
180˚
TO AMP
LOOP
FROM AMP
LOOP
FROM AMP
SPKR OUT
#2
LOW LEVEL
OUTPUT
LOW LEVEL
INPUT
WARNING: USE EITHER INPUT, NOT BOTH.
HIGH LEVEL
INPUT
RETURN
SEND
RETURN
LEVEL SEND LEVEL
EFFECTS LOOP
z IN
250K Ωz OUT 560 Ω
RETURN SEND
OUTPUT INPUT
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
SIGNAL PROCESSOR
Connecting a KnuckleHead II to a Sub 1 or Sub 2
Using a shielded cord, connect the KnuckleHead II’s Effects Loop Send jack to the Low Level input of the Sub
1 or Sub 2. Use two more shielded cables to connect the Sub’s Effects Loop Send to the input of your effects
unit, and from the effects unit’s output to the Sub’s Effects Loop Return. Add one more shielded cord from the
Sub’s Low Level Output to the KnuckleHead II’s Effects Return jack .The connections are complete. Set the
Sub’s Phase switch to either 0ºor 180ºdepending on which setting sounds the loudest. To biamplify the signal
returning to the amp’s power amp section, set the Filter switch to the “High Pass” setting.This filters the return-
ing signal so that only the high and mid frequencies come through the amp’s speaker(s). By setting the Filter
switch to “Full Range,” your signal remains unfiltered, returning all of the signal’s frequencies to the amp.To set
the Sub’s volume output, play your guitar and dial up the pot until the signal clips (indicated by the green LED
light turning red), and then turn down the level just enough so that it no longer clips (the LED remains green).

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5
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
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CARE &TROUBLESHOOTING
Chances are, you bought your RIVERA amp to make your guitar sound great, not to improve your
skills with electronics. What we’re saying is, “If something ever goes wrong with your amp, don’t try to
fix it yourself.” There are some potentially lethal high voltages inside the amp, plus if you do something
that causes even more damage than when you started out, the person who does the real repair will
probably tell you, “Hey, I know what’s wrong. Somebody’s been monkeying around in here.” And, of
course, your warranty will be void.
There are some things you can do to keep your amp running and to determine (and hopefully remedy)
common difficulties.
Keep the amp out of the elements. A lot of this is common sense. Don’t use your amp in a sauna or in
the bathtub. Don’t leave it out in the rain or in a damp basement. If you take it to a gig or to practice
and it’s cold out, give it 15 minutes or a half-hour to stand in the room where you’ll be playing. That
way, it can get acclimated and sound its best when you’re ready to play.
Be nice to it. The jury is still out on whether talking to plants makes them happy, or whether Elvis
lives on the moon, but the verdict on pampering amps is well-known. Don’t drop, knock over, kick, or
otherwise mistreat your amp. If you don’t have a flight case for travel, use the box it came in, or wrap it
in something thick, soft, and protective. RIVERA amps are built to take a lot, but why push it? If you
treat your amp well, it will treat you (and your guitar’s tone) well.
Check for loose tubes. Here’s as close as you should get to being inside your amp. With the amp
unplugged and cooled off, examine the tubes to make sure they’re in tight and straight. Note: Unlike
light bulbs, tubes push straight into their sockets. Never try to twist them! Also note that some of the
tubes are inside of metal sleeves. These are easy to remove for checking the tubes. Grasp the sleeve with
your fingers and depress it (it’s spring-loaded) and turn to the left (counterclockwise). Now pull it off;
this may require a little wiggling action. Remember to put the sleeve back on after you check the tube.
Make sure the power cord is tightly plugged in. This is critical at both ends of the cord. And don’t use
one of those 3-pin-to-2-pin adapters unless you connect the ground lug to the outlet. Leaving the
ground disconnected isn’t just cheating—it’s dangerous to unground any electrical device that’s sup-
posed to be grounded.
Let it idle before you play. If you have a few minutes to spare before you play, turn the amp on and set
it to standby so that all the parts can get warmed up and stable. Once the amp’s nice and warm (5 or
10 minutes), flip the Standby switch and get busy on your guitar.
Don’t use the back of the cabinet as a storage locker. Remember, there are glass tubes in there. They
cost money to replace (money that’s better spent on strings, picks, etc., right?). Stash your other gear in
a bag or a case for travel.
Clean your amp once in a while. You can use a damp cloth or one dipped in a weak solution of dish-
washing detergent and water (lots of water!) to wipe off grime, dried Pepsi, and whatever else accumu-
lates on the vinyl covering. Make sure the amp is unplugged first. Everything else can be vacuumed, as
long as you’re gentle and use a soft-bristled brush attachment on the vacuum hose.

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6
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
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QUICK TROUBLESHOOTING GUIDE
Amp won’t turn on
1. Make sure that the AC mains cord is securely connected at both ends.
2. Verify the power source with something that you know works (a radio, a light, etc.).
3. Check the Mains Fuse, and replace it if necessary (if it blows again, refer your amp to qualified
service personnel)
There’s no sound
1. Make sure that the guitar cord to the input is okay (wiggle it—check your guitar’s volume setting, too).
2. Check the Gain controls.
3. Check the Standby switch.
4. If an effect or signal processor is plugged into the Effects Loop, make sure it’s turned on and that
the level controls on the amp and processor are set correctly.
5. Check the speaker cable or cables to see if they are disconnected or shorted.
6. Check for blown speakers.
7. If a fuse is blown, replace it (if it blows again, refer your amp to qualified service personnel).
The amp shuts down unexpectedly
1. Follow the seven steps in the “There’s no sound” section.
2. Turn off the amp and wait 25 minutes before turning it on again. An internal thermal protection
circuit can shut the amp down if it becomes overheated.
3. After 25 minutes, turn it on, and if it shuts down again, refer the amp to qualified service personnel.
Note: On SEMKO 230-volt models, there are two additional T1.6A (250-volt Slo-Blo type, 5mm
x 20mm) fuses and one T10A (250-volt Slo-Blo type, 5mm x 20mm) fuse located internally. These
protect the amp’s output tube filaments and should only be replaced by qualified service personnel.
There’s unwanted distortion
1. Check the speaker.
2. Check the cables.
3. Check the signal level at other devices in the signal path.
4. One or more tubes may be bad (refer to the tube information on page 17, or take your amp to qualified
service personnel).

20
19
18
7
Knuckle
Head II
®
PRESENCE
POWER STANDBY FOCUS MASTER 2 BASS MIDDLE TREBLE GAIN 2 MASTER 1 TREBLE MIDDLE BASS GAIN 1
BOOST SWEET SCOOP BOOST SELECTNINJA NOTCH BRIGHT
INPUTS
LOW
GAIN HIGH GAIN
HANDCRAFTED BY
RIVERA RESEARCH & DEVELOPMENT SYLMAR, CA USA
PULLPULLPULLPULL
CLEAN/RHYTHM LEAD/CRUNCH
PULL PULL PULL PULL
10
9
8
7
6
5
4
3
2
1
10
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TUBE CARE & REPLACEMENT
Like a sports car, there’s a certain amount of wear and tear to be expected in a high-performance tube
amp. Over time, especially with hard use, tubes may need replacement. That’s why it’s a good idea to
make note of when you purchased your amp and whenever you replace tubes. It’s no accident that your
amp has two common types of tubes: They’re great-sounding and reliable, and it’s easy to find replace-
ments. Here’s a tube chart to show you which tubes go where.
Location Type
V1 12AX7 (WA/WB)
V2 12AX7 (LP/LPS)
V3 12AX7 (WA/WB)
V4 12AX7 (WA/WB)
V5 12AX7 (LP/LPS)
V6 6L6 or EL-34
V7 6L6 or EL-34
V8 6L6 or EL-34
V9 6L6 or EL-34
Here’s a brief description of what each tube does:
V1 Input buffer and tone control driver for Rhythm Ch., and also the first preamp stage of Lead Ch.
V2 Tone control follower for Rhythm Ch. and an additional gain stage for Lead Ch.
V3 Third gain stage for Lead Ch. and final gain stage for Rhythm Ch.
V4 Final gain stage for Lead Ch. and mixer for both channels
V5 Phase inverter driver tube for the power amp section
V6 - V9 Power amp tubes—for best operation, all power tubes should be changed at the same time
Checking for microphonic tubes
As tubes wear, some problems can come up. One of the most common symptoms is a ringing sound.
This is usually due to the tube becoming microphonic (like its name suggests, it’s picking up sound and
amplifying it).
With the amp unplugged and cooled off, examine the tubes to make sure they’re in tight and straight.
Never twist them! Gently grasp the tube and wiggle it into place. Because some of the tubes are inside
of metal sleeves, you will have to remove the sleeves to check them for microphonics. Grasp the sleeve
with your fingers and depress it (it’s spring-loaded) and turn to the left (counterclockwise). Now pull it
off; this may require a little wiggling action.
V6 V7
V1 V2 V3 V4 V5
V8 V9