HK hu1405 schematic

Service Documents

Confidential, for authorized service technicians only!

Do not disclose this information to or share these documents

with third parties.

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Nicht zur Weitergabe an Dritte freigegeben!

TECHNICAL SERVICE:
Stamer Musikanlagen GmbH • Magdeburger Str. 8 • 66606 St.Wendel • Germany
Music & Sales P.E. GmbH • Leipziger Str. 3 • 66606 St.Wendel • Germany

Note!

The components used in this product - particularly parts
affecting safety as well as speakers and transformers ­were developed and manufactured to certain specifications.
Please use original spare parts only to ensure the product
remains fully functional and safe.

Achtung!

Die in diesem Produkt verwendeten Komponenten, insbeson­dere sicherheitsrelevante Teile, Lautsprecher und Transforma­toren wurden nach spezifischen Vorgaben entwickelt und ge­fertigt. Bitte benutzen Sie ausschließlich Original-Ersatzteile –
nur so ist die volle Funktionalität und Sicherheit gewährleistet.

SwitchBlade

Series

SB Head

2006/08/28

Directory

features page: 3-11

drawing-numbers-example page: 12

standard for single wire confection page: 13

HU1405-SwitchBlade Head page: 14

exploded drawings: complete Rev.: A page: 15

wooden cabinet Rev.: A page: 16
chassis/ cabling Rev.: A page: 17-20
preamp assembly Rev.: A page: 21
poweramp assembly Rev.: A page: 22
preamp Rev.: 2B page: 23-25
poweramp Rev.: D page: 26-27
FX-board Rev.: C page: 28
footswitch Rev.: A page: 29

spare parts list Rev.: A page: 30-33

circuit diagrams preamp Rev.: 2A page: 34-36

poweramp Rev.: F page: 37-38
FX-board Rev.: C page: 39
footswitch Rev.: A page: 40

layout diagrams preamp Rev.: 2A page: 41

poweramp Rev.: D page: 42
FX-board Rev.: C page: 43
footswitch Rev.: A page: 44

Switchblade

1 The Fundamentals of Handling

SWITCHBLADE is a tube amp and, as such, works like as a tube amp.

Nevertheless, the handling concept is rather advanced, so time spent
familiarizing yourself with it is time well spent.

At first glance, the knobs look and feel like standard-issue gear:
Control range 300 degrees; 0-10 clockwise; left and right stops.

At second glance, though, you’ll discover that there is just a single set
of knobs to serve all four Channels. One
one three-band EQ – that’s it. The selected Channel determines if the

GAIN knob addresses the CLEAN, CRUNCH or LEAD Channel.

The great advantage of this concept is that Channels are independent
and do not share the Gain, Master or voicing knobs; even Presence
is separately adjustable for every Channel and every setting can be
programmed individually to each of the 128 Presets!

Apart from the

STANDBY), this applies to all of SWITCHBLADE’s control features, that is:

VOLUME MASTER knob (and of course MAINS and

• the Channels: CLEAN, CRUNCH, LEAD, ULTRA

• the Channel settings: GAIN+BOOST, BASS, MID, TREBLE,

PRESENCE, MASTER

• the effect parameters: MOD FX, TIME, FEEDBACK, VOLUME, REVERB

• the effect routing options for external devices: FX ON/OFF, SERIAL/PARALLEL

GAIN, one Channel MASTER,

reflect the setting programmed in the Preset. This means you may
well hear something other than what you’re seeing would suggest. As
soon as you touch the knob, it will respond like any other conventional
knob. The ORIGINAL VALUE LED in the
the Preset setting. It lights up as soon as the position of the knob
corresponds to the Preset setting. More on this in chapter 4.3.

Note: You may hear a soft background sound when you twist the
knobs. This is a switching noise made the programmable resistor
matrix located behind each knob.

MASTER section tells you

2 The SWITCHBLADE’s Channels

SWITCHBLADE offers four Channels with markedly different sonic

characters. Courtesy of
more and more powerful sound-shaping options: The knobs are not
hardwired to the internal circuits, so we were able to tweak their
control ranges and performance to make the most of each Channel’s
characteristic sound.

A chickenhead knob is sited at the far right of the
that’s the Channel Selector. Use it to switch among the four Channels
along with their
settings.

SWITCHBLADE’s programmability, you enjoy

CHANNEL section–

GAIN, BASS, MID, TREBLE, PRESENCE and MASTER

You won’t find any control features for managing the 128 Presets
on Switchblade. The included FSM 432 MIDI board or another MIDI­enabled controller serves to select Presets and assign memory slots.
More on this in chapter 6.

Note: A knob setting programmed in a Preset and the knob’s actual
setting are not necessarily the same. They are independent: When you
switch from one Preset to another, the knob’s actual position may not

16

Note: When you first power up your amp and change Channels, you will

dial up factory settings (see chapter 6.3.2 to learn more). As soon as you
begin dialing in sounds to your taste, it will adopt your Channels settings.
And it recalls your most recently configured sound for each Channel. You’ll
find this to be a tremendous help when programming. More on this in
chapter 6.

2.1 Clean Channel

Tuned to rival classic Californian tone, Switchblade’s Clean Channel
delivers a spectrum of sweet sounds ranging from crystal-clear to
remarkably responsive Crunch tones. The programmable Presence control
adds silken warmth as well as sparkling shimmer to the sonic equation.

Switchblade

2.2 CRUNCH Channel

Classic British overdrive à la carte! The

CRUNCH Channel covers the

diverse tonal spectrum from Clean to mean, and all points in between.
The Gain control’s integrated Boost function transforms tight rhythm
tone into a throaty growl perfect for rockin’ riffs.

2.3 LEAD Channel

The LEAD sound is the first choice for hard-rockin’, classic British
high-GAIN tone to fuel Leads, power chords and riffs. Courtesy of its
fine-tuned compression, this Channel delivers the lubricant that makes
those slick riffs and licks fly off your fingertips.

2.4 ULTRA Channel

American high-Gain sound with sumo-sized low end and snarling top
end. The

ULTRA Channel delivers the kind of merciless performance

that is sure to delight nu metal meisters and dropped tuning
aficionados. Ultra is also an alluring alternative for guitarists seeking to
super-size their sound with a high-calorie topping of rich tone.

2.5 GAIN

The GAIN knob determines Input sensitivity and thus the Level of
saturation and distortion.
feature: Just before the knob arrives at the far right position, a

SWITCHBLADE’s GAIN offers a special

BOOST

stage kicks in (and the red LED lights up). Now, when you see Boost
on other amps, this usually means all frequencies are boosted. But
Switchblade’s Boost amplifies selected frequency ranges for each
Channel to attain creamier tone.

2.6 BASS, MID, TREBLE

The voicing section is tweaked to accomplish the best, most efficient
sound-shaping for each Channel. Getting right to the heart of the sonic
matter, every knob addresses each Channel’s characteristic frequency
ranges. Like on every tube amp, the knobs of a Channel influence each
other. That is, if you boost the Treble, the midrange is cut and vice
versa. This puts a much greater range of subtle tonal variations at your
fingertips.

2.7 PRESENCE

This knob determines the overtone content. Unlike a
which boosts whatever high frequencies are available,

TREBLE knob,

PRESENCE

actually determines the amount of harmonic overtones generated by
the amp. Usually a

PRESENCE knob controls the overtone content

of the overall amp rather than of individual Channels. Courtesy of

SWITCHBLADE’s programmability, you can define PRESENCE settings

not only for each Channel, but also for each Preset.

2.8 MASTER

Use the Channel

MASTER knob to adjust the given Channel’s Volume

and balance it out with the other Channels’ Levels. On Switchblade this
knob serves another vital purpose: It lets you store the same sound
at different Volumes to any of the 128 Presets, for example, a softer
version for rhythm and a louder setting for Leads.

Note: The Channel MASTER is a different breed of knob. It adjusts the
Channels’ relative levels, and is tweaked to help you quickly dial in the
best balance. Unlike a conventional Master knob, it can’t be turned

all they way Down; it merely boosts or cuts the given Level. This
design makes musical and practical sense: The Clean Channel normally
requires a much higher Master Level than a distorted Channel, which
is why it is about as loud as the other Channels when the knob is set
to the center position. That’s why the 12 o’clock position is always the
best starting point for adjusting Volume.

3 Digital Effects

SWITCHBLADE offers three independent digital effect sections that can

be used simultaneously. Like Channel settings, all ef fect settings are
programmable.

Note: The internal effects are added to the signal via an intelligent
analog circuit. Effect routings in no way comprise the integrity of
SWITCHBLADE’s tube tone, which remains intact in all its quality.

3.1 REVERB

SWITCHBLADE’s Reverb is modeled to match the warmth and musicality

of classic spring Reverbs. A genuine improvement over its analog
forebears, it automatically adjusts the Reverb tail to suit the setting: The

REVERB you add to the signal, the longer the REVERB time.

more

3.2 DELAY

The Delay section’s
total control over all parameters. This lets you dial in everything from
rockabilly style slap-back echo to U2-inspired Delay extravaganzas and
Queen-like bombast.

3.2.1 VOLUME

Adjusts the Volume of the repetitions, sweeping from all the way off to
just as loud as the original signal.

3.2.2 FEEDBACK

Adjusts the number of repetitions from one to infinite.

3.2.3 TIME

Adjusts the Time to the next repetition from 80 ms to 1.4 s.

TIP: TIME can be remote-controlled via the included FSM 432 using
the TAP function. This lets you respond quickly and conveniently to
timing changes. You’ll find TAP to be a very helpful feature, particularly
on stage! More on this in chapter 6.1.3

3.3 MOD FX

The three most important modulation effects are
and TREMOLO, and they’re all on board, readily activated via a single
knob. CHORUS is active in the first third, FLANGER in the second third,
and TREMOLO in the final third of the control range. You can shape the
effect within its assigned third of the control range using this knob. The
parameters were tweaked to make musical sense: A twist of the knob
is all it takes to get the desired effect. Twisting clockwise adjusts the
rate of the modulation effects. Modulation depth is adjusted

VOLUME, TIME and FEEDBACK knobs afford you

CHORUS, FLANGER

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17

Switchblade

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automatically according to the rate so that every knob position gives
you the best effect sound. To switch modulation effects off, simply
twist the knob to the far left-hand position.

3.3.1 CHORUS

At slow settings, the

CHORUS sounds thick and lush, providing a great

sound for buoyant ballads. And because effect depth is adjusted auto­matically, fast

CHORUS settings don’t evoke that dreaded seasick tone.

3.3.2 FLANGER

Slow FLANGER settings yield a stately sweeping whoosh effect, while
faster settings give you swirly effects often heard in contemporary rock
and pop tunes.

3.3.3 TREMOLO

The classic

TREMOLO effect is great for dialing in typical sounds of the

‘60s as well as contemporary effect sounds.

4 Master

The Master section lets you adjust the amp’s overall Volume, route
external ef fects, and store Presets.

4.1 VOLUME

4.4.1 SERIAL

Switches the effects loop from Parallel (LED does not light up) to Serial
(LED lights up).

4.4.2 FX ON

Switches the effects loop on (LED lights up) and off (LED does not light up).

Tip: If you have not inserted an effect device into the FX Loop, you
can use this circuit for other purposes and store the configurations
individually in each preset:

•

In parallel mode, you can use the RETURN jack to connect a second

instrument or any other audio source. You can also route the amp’s
signal to a second power amp.

•

In serial mode, the effects loop lets you control the amp’s volume

remotely by simply connecting an analog Volume pedal to
RETURN.

Caution: The signal chain is severed if the effects loop is configured
serially and no effect device is connected. Send is not the best to-mixer
routing option because it accesses the preamp signal only. Patch the
power amp signal to a mixing console via the Hughes & Kettner
Red Box® and the speaker outputs.

SEND/

5 Rear Panel Connections and Control Features

As the name would indicate, this knob puts the power amp at your
thumb and forefinger’s command. Exercise restraint when handling
this knob to make music a pleasant rather than a painful experience.

Handling: Unlike the Channel and effect knobs, the MASTER VOLUME
knob is not programmable! It works like any standard knob, and the
position of the knob indicates the actual setting.

Caution: High volume levels can cause hearing damage. Spare yourself
a nasty surprise and twist the MASTER VOLUME knob to the far left­hand position before powering the amp up.

4.2 STORE

STORE button to save your Presets. See chapter 6.4

Use the
for more info.

4.3 ORIGINAL VALUE

This LED tells you which knob setting is stored in the given Preset.
To this end, select a Preset, grab the knob and twist it to the left or
right until this LED lights up. The setting at which the LED lights up
corresponds to the setting stored in the Preset.

4.4 FX LOOP

SmartLoop™ is a special effects routing circuit offering a switchable
Parallel/Serial effects loop for patching in external ef fect devices.
Its status is stored in each Preset, that is, whether it is on or off and
configured in a parallel or serial circuit.

18

5.1 EFFECTS ON/OFF

®

This port accepts the two-way Hughes & Kettner

FS-2 footswitch.
Button 1 switches internal effects; button 2 the external effects loop.
The FS-2’s LED lights up to indicate ef fects are active and the

FX ON

button is engaged. It does not light up if the internal effects are
bypassed or the

Note: The footswitch deactivates the FX ON button on the front panel!
When a footswitch is connected, it always has priority. The current
status of the footswitch is valid when switching Channels, irrespective
of the switching status stored in the preset! The front panel FX ON
button now serves as an LED display indicating the status of the
footswitch.

FX ON button is switched off.

5.2 CHANNEL SELECT

If you ever leave your MIDI board behind, this flexible fall-back
connector for footswitches will help get you through the gig. It lets
you switch remotely between two Channels, say
using standard one-way footswitches such as the Hughes & Kettner
FS-1. A two-way footswitch such as the Hughes & Kettner

CLEAN and ULTRA,

®

FS-2

®

may also be connected. In this case, button 1 is responsible for the
Channels, and button 2 is disabled.
four-way Hughes & Kettner
Kettner® Trilogy and Matrix amp. It lets you switch all four Channels.

SWITCHBLADE even accepts the

®

FS-4 footswitch that ships with Hughes &

Switchblade

Note: The footswitch changes the Channels only, and not presets.

That is, it activates the most recent Channel settings and it does not
switch effects.

5.3 FX LOOP

If you wish to use an external effect device, you can insert it into the

FX LOOP.

5.3.1 FX SEND

Connect this jack to your effects processor‘s input jack.

5.3.2 FX LEVEL

This button cuts the

FX RETURN’s input sensitivity by 10 dB to match the FX Loop to the

FX SEND’s output level by 10 dB and boosts the

effect device’s input level. Press this button when using processors
designed to handle instrument levels.

5.3.3 FX RETURN

Connect this jack to your effects processor‘s output.

5.4 MIDI

SWITCHBLADE is MIDI-enabled, meaning that it communicates with

other MIDI devices.

5.4.1 MIDI IN

®

Connect the included Hughes & Kettner

FSM 432 or any other MIDI
sender to this port so that you can select and switch Presets remotely.
Though this is a seven-pin port, you can connect a standard five-pin
MIDI cable. The two additional terminals serve to supply phantom
power to the FSM 432.

in parallel, the resulting resistance (R) is calculated by multiplying the
two individual resistances and dividing their product by the sum of the
individual resistances. Use the following formula to do this:

R = ( R1 x R2 ) / ( R1 + R2 )

Take as an example a one 8-ohm and one 16-ohm cabinet:

R = ( 8 x 16 ) / ( 8 + 16 )
R = 128 / 24
R = 5.33

The cabinets’ impedance may never be lower than the amp’s output
impedance, so this combination must be connected to the 4-ohm
output. However, we strongly advised against configuring setups with
mismatched cabinets, and highly recommend using combinations of
cabinets with the same impedance!

6 MIDI Control and Programming

6.1 FSM 432

The included Hughes & Kettner
control serving to select the 128 memory slots conveniently arranged
in 32 Banks of four presets each. You can easily configure setups any
way you wish, say by assigning the four presets of a bank to a song.

®

FSM 432 MIDI board is a remote

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5.4.2 MIDI THRU

This port forwards signals patched into the

MIDI IN port to other

devices. You can connect any external MIDI-enabled signal processor
or any MIDI receiver that you wish to switch synchronously with

SWITCHBLADE.

5.5 SPEAKERS

SWITCHBLADE offers separate outputs for all standard impedances:

You have 1 x 4-ohm, 1 x 8/2 x 16-ohm, and 1 x 16-ohm outputs at
your disposal. Always ensure the impedance (that is, the ohm value) is
correct. Mismatches can corrupt the sound (high-impedance speaker
connected to a low-impedance output) and harm the amp (low­impedance speaker connected to a high-impedance output).

Note: You may of course connect several cabinets to one port, even
if they have different impedances. Usually speaker cabinets are
connected in Parallel. Two cabinets of the same impedance connected
in Parallel have half the impedance of a single cabinet. For example, if
you have two 8-ohm cabinets, you must connect these to the 4-ohm
output. If you connect two cabinets with different impedances (R1, R2)

6.1.1 PRESET A B C D

Presets within a bank can be activated directly, that is, switching from
A to B within the same bank occurs immediately. The LED above the
A,B,C,D buttons indicates the preset.

6.1.2 BANK UP/DOWN

If you want to call up a preset in another bank, you can select the bank
via UP and DOWN while continuing to play using the current preset.
The number of the bank is indicated in the display, and it flashes until
you select a preset via A,B,C,D. Not until then will

SWITCHBLADE load

the new preset.

DIRECT MODE is available if you wish to trigger a direct program

change via bank Up/Down. In this mode, the FSM 432 will not wait for
your input, instead switching immediately, for example, from preset
B in bank 16 to preset B in bank 17 (

UP) bank or 15 (DOWN). Direct

Mode is activated as follows:

• Press and hold TAP, and then press PRESET A.

• First release PRESET A, and then TAP: The decimal point in the

display lights up.

Follow the same sequence to deactivate
than permanent,

DIRECT MODE is automatically deactivated when you

DIRECT MODE. Volatile rather

power SWITCHBLADE down!

19

Switchblade

6.1.3 TAP

The TAP function gives you a very fast and convenient option for
changing the Delay’s
on stage: Simply tap your foot on the
groove to match delay Time to the tempo. The ef fect adopts the new
time after the second tap. The
in time with the beat to give you a visual indication of the delay time.

Note: The TAP function works only when the DELAY is active. If the
DELAY is off, the effect will not adopt your TAP tempo.

6.1.4 Switching External Devices via the
FSM 432, Setting the MIDI Send Channel

If you wish to switch devices connected to
– say, a MIDI effect device – using the FSM 432, ensure the effect
device is set to the FSM 432’s MIDI Channel or to
device’s manual for more info.

To set the FSM 432’s MIDI Send Channel, proceed as follows:

• Turn SWITCHBLADE on while pressing the FSM 432’s PRESET A

button. The display flashes.

• Release button A. Use UP/DOWN to view and set the MIDI Channel

to a number between 1 and 16.

• Quit and store by pressing the PRESET A button.

Caution: If SWITCHBLADE and FSM 432 are not set to the same
MIDI channel, the amp will not respond to program changes!
Activating OMNI solves the problem in the event of an “emergency.”
See chapter 6.2 to learn more.

Note: If an external effect device is connected to MIDI THRU and
you want to switch Switchblade and the effect device simultaneously
with the same program change command, you must configure
Switchblade’s Store function and program this device accordingly.

Note: The table above should be big help if you wish to switch the
Presets of a device connected to the MIDI THRU directly via the
FSM 432. It shows the program changes sent by the bank/preset
combination. Please bear in mind that some MIDI devices switch
program 1 via program change command 0. If this is the case with
your outboard gear, simply add a 1 to each value indicated in this
table to activate the desired program.

TIME parameter. TAP comes in particularly handy

TAP button in Time with the

TAP LED flashes for about five seconds

SWITCHBLADE MIDI THRU

OMNI. Consult the

Bank

Preset

Programchange

Number

Bank

Preset

Programchange

Number

Bank

Preset

Programchange

Number

Bank

Preset

Programchange

Number

1 A 0 9 A 32 17 A 64 25 A 96
1 B 1 9 B 33 17 B 65 25 B 97
1 C 2 9 C 34 17 C 66 25 C 98
1 D 3 9 D 35 17 D 67 25 D 99
2 A 4 10 A 36 18 A 68 26 A 100
2 B 5 10 B 37 18 B 69 26 B 101
2 C 6 10 C 38 18 C 70 26 C 102
2 D 7 10 D 39 18 D 71 26 D 103
3 A 8 11 A 40 19 A 72 27 A 104
3 B 9 11 B 41 19 B 73 27 B 105
3 C 10 11 C 42 19 C 74 27 C 106
3 D 11 11 D 43 19 D 75 27 D 107
4 A 12 12 A 44 20 A 76 28 A 108
4 B 13 12 B 45 20 B 77 28 B 109
4 C 14 12 C 46 20 C 78 28 C 110
4 D 15 12 D 47 20 D 79 28 D 111
5 A 16 13 A 48 21 A 80 29 A 112
5 B 17 13 B 49 21 B 81 29 B 113
5 C 18 13 C 50 21 C 82 29 C 114
5 D 19 13 D 51 21 D 83 29 D 115
6 A 20 14 A 52 22 A 84 30 A 116
6 B 21 14 B 53 22 B 85 30 B 117
6 C 22 14 C 54 22 C 86 30 C 118
6 D 23 14 D 55 22 D 87 30 D 119
7 A 24 15 A 56 23 A 88 31 A 120
7 B 25 15 B 57 23 B 89 31 B 121
7 C 26 15 C 58 23 C 90 31 C 122
7 D 27 15 D 59 23 D 91 31 D 123
8 A 28 16 A 60 24 A 92 32 A 124
8 B 29 16 B 61 24 B 93 32 B 125
8 C 30 16 C 62 24 C 94 32 C 126
8 D 31 16 D 63 24 D 95 32 D 127

6.2 Setting Switchblade’s MIDI
Channel and Switching OMNI

Press the

SERIAL button longer than two seconds when SWITCHBLADE

is in normal operating mode, and the

ON/OFF

ORIGINAL VALUE LED will start

flashing. This assigns special programming functions to the amp’s LEDs
and buttons:

20

FX ON

Now serves as a +1/

UP button for setting the MIDI Channel.

Serial

Now serves as a -1/

DOWN button for setting the MIDI Channel.

Store

OMNI ON/OFF switches. If the STORE button (OMNI On) lights up,
SWITCHBLADE responds to all incoming program changes, irrespective

of the MIDI Channel over which they are sent. If the light on the button
is extinguished (

OMNI OFF), it responds only to messages sent via the

defined MIDI Channel.

Switchblade

FACTORY SETTING: MIDI CHANNEL = 1, OMNI = ON

Note: OMNI ON is helpful if you are unsure via which channel
a connected MIDI device sends its messages.

During the MIDI setup routine, the LEDs that normally indicate the
preamp Channel indicate the MIDI Channel. The following table MIDI
Channel lists the MIDI Channel settings in what is called binary code:

MIDI-Kanal Boost Clean Lead Ultra

1

2

3

10

11

12

13

14

15

16

4

5

6

7

8

9

Press and hold SERIAL for a few moments to quit the MIDI setup
routine and store the settings. The amp returns to its most recent
operating status (normal mode).

6.3 Factory Settings and Factory Reset

A factory reset is a seldom needed feature. Nevertheless, be sure to
read the explanation carefully to ensure you don’t accidentally delete
your presets.

6.4 Storing Settings/Programming

You have two options for storing a preset to one of the 128 memory
slots: Select a new memory slot via MIDI (6.4.1) or overwrite the
preset directly at the device (6.4.2).

6.4.1 Selecting a New Memory Slot via MIDI Learn

• Press the STORE button briefly; it lights up to signify that it is armed

(MIDI Learn).

• Select a MIDI bank from 1 to 32 on the FSM 432; it flashes to signify
that the FSM 432 is waiting for input via one of the four preset
buttons A to D.

• Engage preset button A,B,C or D; the board stops flashing, the light

STORE button extinguishes, and the preset is stored.

on the

Caution: When the FSM 432 is in DIRECT MODE (see chapter 6.1.2),
a BANK UP/DOWN command also triggers the storage process! We
recommend deactivating Direct Mode when programming to prevent
inadvertent overwriting of presets.

Note: Here’s how to proceed for other manufacturers’ MIDI boards
and MIDI-enables devices: Arm
STORE button and selecting the desired memory slot. As soon as
SWITCHBLADE receives a valid program change command, the STORE
button extinguishes and the preset is stored.

SWITCHBLADE by engaging the

If an error occurs (the amp remains armed), you can cancel the storage
process by pressing

STORE again.

6.4.2 Overwriting Presets Directly at the Device

There is an easier way to overwrite the most recently selected preset
than going from the amp to the MIDI board and back after every edit:
Press and hold the
about two seconds). The
flash to confirm. Then you can release the

STORE button until its light extinguishes (after

ORIGINAL VALUE and the Channel LEDs also

STORE button and your

settings are stored.

7 Replacing Tubes, Service

and Preventive Maintenance

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6.3.1 Triggering a Factory Reset

If you press

STORE and FX SERIAL simultaneously while powering the

amp, all settings are reset, including the 128 MIDI-switchable presets
and the basic MIDI configuration.

6.3.2 Factory Presets and Basic MIDI Configuration

The A to D presets of all banks correspond the channel settings; that is,
all 32 banks have the same settings: Preset A corresponds to Clean, B
to Crunch, C to Lead, and D to the Ultra Channel.

The basic MIDI configuration is:

• OMNI ON • MIDI Channel: 1

• FX ON is switched off. • SERIAL is deactivated.

CAUTION: This procedure is a last-resort option! It irrevocably wipes
out all stored settings.

SWITCHBLADE is factory-loaded with EL34 and 12AX7 tubes. Once

they’ve been burned in – that is, operated continuously under a load –they
are subjected to a rigorous selection process. Their electrical specs and
mechanical status (microphonics) are checked, and then they are installed
in an amp and their sonic performance is auditioned. One of the most
important steps in this process is tube matching, whereby tubes with the
same characteristics are teamed up in matched sets of power tubes.

When to Replace Tubes

The tubes in

SWITCHBLADE are exemplary in terms of quality,

workman-ship and long service life. Nonetheless, tubes show definite
signs of wear when their service life is nearing its end. Telltale signs are
increased microphonics, noise and hiss, muddier tone through loss of
high-end frequencies, degraded performance, etc. Take these indications
seriously and replace old tubes. Not only do these side effects take their
toll on sound quality, they also indicate the aging tube will soon fail!

21

Switchblade

Note: Replacing tubes for experimentation purposes is not

recommended. Installing the wrong tubes will damage the amp and
cost you a lot more than you bargained for in repair costs.

Before you start swapping tubes, ask yourself these questions:

• Was the fault or failure of the tube caused by the tube itself or by a
flawed peripheral device or component, perhaps a defective speaker
cable? If you don’t get to the bottom of the problem and remedy it,
it may crop up again even after you replace the tubes.

• Did the Mains voltage fluctuate or spike while the amp was on? In
all-tube amps, over-voltage surges in the Mains net can certainly
cause drop-outs. Over-voltages are often caused by generators and
faulty high-current power circuits.

• Perhaps a fuse blew even though none of the tubes is actually
defective? An old fuse, tube de-ionization or Mains voltage power
surges may have triggered the fuse.

Things to Bear in Mind When Replacing Tubes

Replacing tubes is a job best left to qualified professionals!
Accordingly, the following guidelines are addressed and apply to
qualified service technicians only:

• Pull Switchblade’s Mains plug and allow for a discharge time of at least
two minutes before removing the chassis from the rear of the amp.

• Once the chassis has been removed, carefully ease the tubes out of
their sockets.

• A single power tube may only be replaced if the replacement tube
precisely matches the original, that is, the old and new tubes’
characteristics are identical.

• When a new matched set of power tubes with characteristics
identical to the old set is installed, it is not absolutely necessary to
re-bias the amp.

• The amp must be biased when a replacements set’s characteristics do
not match the original set’s. This requires experience and extensive
working knowledge in measuring techniques, which is why this is a
job for qualified technicians with tube amp tuning experience.

How to Prolong Tube Life

• Never operate Switchblade without connecting a load (loudspeaker)!

• Never connect speaker cabinets with an impedance that is too high

or low!

• Always use high-quality, heavy-duty speaker cords that won’t crimp!

• Use the STANDBY switch for short breaks!

• Avoid exposing the amp to vibrations, especially when it’s powered up.

• Switch the amp off well before transporting it to allow tubes to cool

off completely.

• Make sure all peripheral devices and connecting cords are in a state
of good repair!

• Ensure air can circulate freely around the amp’s ventilation slots at
all times!

• Never expose Switchblade to extreme heat or cold!

• Prevent the intrusion of dust and moisture!

• Always check peripheral gear’s specs to ensure these accessories are

suitable for the amp.

• Never connect devices with high output signal Levels to
Switchblade’s Input.

• Never operate the amp with Mains power that is too high or too

22

low. When in doubt ask the venue’s sound technician or facility
engineer.

• Refrain from DIY repairs! Also have a qualified technician replace
internal fuses.

8 Troubleshooting

Mains connection: SWITCHBLADE
won’t power up when you switch it on.

• It‘s not getting AC power. Check the Mains cord to see if it is
connected and firmly seated.

• The Mains fuse is defective. Ensure it is replaced with another fuse
bearing the same rating.

• The local Mains voltage does not match Switchblade’s operating voltage

Available Voltages and How to Adapt Them

Switchblade ships in two versions rated for 110/120V and 220-240V.
You will find the rating indicated on the housing above the Mains
socket. Both models offer two operating voltages that are selected
using the voltage selector integrated in the Mains socket. Ensure that
the Mains voltage matches the voltage rating appearing in the voltage
selector window. This value is legible when the amp is in the standard
operating position, that is, placed right side up. The upright number
indicates the currently selected voltage, and the inverted number
indicates the alternative voltage. Check also the fuse ratings to ensure
they match the ratings indicated on the rear panel.
Voltage selection and fuse replacement may be performed by
experienced service technicians only. Accordingly, the following notes
are addressed exclusively to service technicians:

• Use a small flat screwdriver to remove the voltage selector from the
Mains socket.

• If the fuse is defective, replace it with a fuse bearing the specified rating.

• Turn the voltage selector and insert it back into the port so that the

desired Mains voltage rating is legible and appears at the top left
(next to the “Voltage Setting” arrow).

HEAD / COMBO 100

Switchblade

COMBO 50

Switchblade is connected
properly, but no sound is audible.

• The guitar’s VOLUME knob is turned all the way down.

• The amp is set to STANDBY.

• The amp’s VOLUME knob is turned all the way down.

• The effects loop is active and set to SERIAL, but no ef fect device is

connected.

• The anode fuse has blown. Ensure that it is replaced with a fuse of
the same rating.

• The fuse for the tube heating tripped (the tubes don’t glow). Ensure
that it is replaced with a fuse bearing the same rating.

The amp makes ringing noises
when played and tends to Feedback.

• One or several tubes are microphonic. Replace the defective tube
with another of the same type.

Signs of tube wear such as increased microphonics and
noise, Treble loss, weak power output or muddy sound
begin reappearing just a few hours after replacing tubes.

• The wrong tubes were installed when old tubes were replaced or
the amp was not biased properly. Take the amp to a professional to
correct the problem.

The sound is washed out or muddy when you switch an
effects processor on.

• The signal processor provides a wet signal that is blended with
the dry or original signal. Depending on the type of effect, the
processor may be returning a dry signal back along with wet signal,
which causes phase cancellations when mixed to the dry signal in
Switchblade’s Parallel loop. To prevent this, set the effects loop
to SERIAL or turn the dry signal all the way down on the signal
processor.

english

23

Switchblade

9 Technical Specifications

All level indications relate to 0 dBV (1V RMS).

9.1 Inputs

INSTRUMENT Input

Input: 6.3 mm (1/4”) jack
Type: unbalanced
Input impedance: 1 MW
Sensitivity: - 50 dB (Clean Channel)
Max. Input Level: 0 dB

FX Return

Input: 6.3 mm (1/4”) jack
Type: unbalanced
Input impedance: 48 k W
Max. sensitivity: -10dB button engaged: - 21 dB,
disengaged: - 11 dB
Max. Input Level: -10dB button engaged: + 0 dB,
disengaged + 10 dB

MIDI IN

Port: DIN 45 329 (7-pin )
Data reception: Program change data, Tap Delay function
Channels: 16, Omni mode
Power supply: 15V DC max. 200mA, pin 6 = positive,
pin 7 = negative

9.2 Outputs

FX Send

Output: 6.3 mm (1/4”) jack
Type: unbalanced
Output impedance: 2.2 k W
Output Level: + 3 dB
Max. output Level: -10dB button engaged: - 2 dB,
disengaged: + 8 dB

MIDI THRU

Port: DIN 45 328 ( 5-pin)
Data handling: All data sent to MIDI IN are patched
out unchanged.

9.3 General Electrical Data

Switchblade 100 Head/Combo Switchblade 50 Combo

Max. current consumption:
440 watts 290 watts

Max. power consumption:

1.75A @ 240 volts 0.97A @ 240 volts

1.89A @ 220-230 volts 1.07A @ 220-230 volts

3.50A @ 117-120 volts 2.00A @ 117-120 volts

3.95A @ 100 volts 2.15A @ 100 volts

Mains voltage tolerance range: +/- 10 %

External fuses (anode):
1 x T 630 mA 1 x T 400 mA

Internal fuses:
1 x TT 10 A Slo Blo 1 x TT 10 A Slo Blo
2 x T 630 mA 2 x T 630 mA

Mains fuse (5 x 20 mm):
Europe: (variable: 220 V-230 V / 240 V
1 x 250 V / T 1.6 A 1 x 250 V / T 1 A
USA/Canada/Asia:( variable: 100 V / 120 V)
1 x 250 V / T 4 A 1 x 250 V / T 2 A

Ambient operating temperature range:
0 °C to + 35 °C 0 °C to + 35 °C

9.4 General Mechanical Data

100 Head 100 Combo 50 Combo

Dimensions: (including corners, handles, feet)
Width: 750 mm 647 mm 600 mm
Height: 280 mm 500 mm 500 mm
Depth: 258 mm 285 mm 285 mm
Weight: 17.6 kg 30.3 kg 22.8 kg

Speaker Outputs

6.3 mm (1/4") jacks: 1 x 4 ohms, 2 x 16 ohms / 1 x 8 ohms,

1 x 16 ohms

Speaker

100 Combo 2 x 12" Eminence® Rockdriver 60
50 Combo 1 x 12" Eminence® Rockdriver 60

24

DRAWING-NUMBERS

EXAMPLE

HK0106-EX-R01-1A

VERSION

SERIAL NUMBER

DEPARTMENT:
R = R&D

REVISION

PROJECT-NR.:
HK = HK AUDIO
HU = HUGHES&KETTNER
MP = MINDPRINT

CHARACTER:
BL = SHEET METAL / BLECH
EX = EXPLODED DRAWING / EXPLOSIONSZEICHNUNG
HZ = CABINET / HOLZGEHÄUSE
KU = PLASTIC / KUNSTSTOFF
LP = PCB / LEITERPLATTEN
SO = MISCELLANEOUS / SONSTIGES
SP = SCHEMATIC / SCHALTPLÄNE
TR = TRANSFORMER / TRANSFORMATOR
GK = WIRING DIAGRAM / GERÄTEVERKABELUNG

Stand

W

Y

r

Standard for single wire confection.

16 B 150 638 I - 485 W Z I 1015

style 1015 according UL specifications

I = completely insulated with black shrinktube or appropriate sleeve
IT = partly insulated; only crimp connection insulated.

no marking = without insulation

Z = with additional junction
no marking = without additional junction

W = angled faston
no marking = straight faston

17. Jun 04

Faston connector brass tin-plated DIN 46245
638 = 6,3 * 0,8 [mm]
488 = 4,8 * 0,8 [mm]
485 = 4,8 * 0,5 [mm] if fully insulated (I) insulation with blue shrinktube

if partly insulated (IT) use IF 602 485 .
288 = 2,8 * 0,8 [mm]
285 = 2,8 * 0,5 [mm] if fully insulated (I) insulation with blue shrinktube

if partly insulated (IT) use IF 602 485

abiso = 5mm bared and tin-plated (teilabzug)
text for special constructions, (for example. 4mm ringshaped faston)

the larger faston connector always mentioned at first. (Nathan drawing number controlling)

lenght in mm within a 50 mm raster

colour
B = black (phase conductor)
R = red
BR = brown
BL = blue (neutral conductor)

= white

G = yellow-green (ground bonding/ earthing connection)

cross section
16 = AWG 16 (prefered usage)
Q1.5 = H07VK 1,5mm² (prefered usage)

wire designation:

P + lfd Nr. = AWG single wire black, red, blue, brown or white
E + lfd Nr. = AWG single wire green- yellow
L + lfd N
FQL + lfd Nr. = crossover wiring H07VK

Regarding special wirings like wiring harness or similar, drawings will be prepared and appropriate

. = twisted AWG double wire, lenght specification always in twisted condition

drawing numbers will be stored in the article archive.

Service Documents

Confidential, for authorized service technicians only!

Do not disclose this information to or share these documents with third parties.

TECHNICAL SERVICE:
Stamer Musikanlagen GmbH • Magdeburger Str. 8 • 66606 St.Wendel • Germany
Music & Sales P.E. GmbH • Leipziger Str. 3 • 66606 St.Wendel • Germany

HU1405

SwitchBlade

Head