VHXD
OWNER’S MANUALDOS 5.04 © 2021 Diezel GmbH. All rights reserved.

IMPORTANT SAFETY INFORMATION
We want you to be aware of certain safety aspects, for reasons of product safety and liability. With all due respect, please read the following before
operating your new Diezel VHX.
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmfulinterference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes ormodifications not expressly approved by Diezel Amplification GmbH could void the user’s authority to operate the equipment.
• DO NOT use or store the device in or near moist or wet areas.
• Check voltage specification at rear of unit before plugging unit in. Make sure that voltage shown is the correct voltage for the location you are using
the device at. Under no circumstances can the amplifier be used at different than shown voltages.
• DO NOT OPEN the device housing. It must only be done by authorized personnel. Your VHX operates on very high internal voltages, which may still
be present after the device has been turned off and disconnected for a while. No user serviceable parts inside• The VHX was designed to amplify a guitar signal and can be used only for this purpose.
• When transporting the VHX please observe the following: The Diezel VHX is a vacuum tube instrument amplifier. Vacuum tubes are shock sensitive,
especially when hot. To avoid damaging the unit, we recommend using care during setup and tear down of the unit. Allow the Amplifier to adjust toambient temperature before operating, 60 minutes should be enough in all cases. The VHX lives inside an extremely rugged chassis, but for continued
road use, please protect the amplifier by using a professional flight case. Transport only in operating position. Do not transport upside down or on its
side.
• The Diezel VHX is configured to deliver highest tone fidelity at “normal volume levels (76 - 80dB). We caution you for your own good not to expose
yourself to very high-volume levels for long periods of time. It can lead to hearing damage.
• Blown fuses can only be replaced with fuses of equal values. The use of incorrect fuses is prohibited and can cause severe injury and damage of theamplifier.
• Use only a grounded power cable in good operating condition.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

d25 YEARS LATER, SETS A NEW BENCHMARK IN TUBE GUITAR AMPLIFICATION. AGAIN.
VHX is the answer for the evolving needs of the guitar player. The unique combination of the distinctive, irreplaceable, fully programmable and fully
analog tube preamp and power amp, with a fresh, simple and intuitive UI opens a world of infinite possibilities with no TONE compromise.

That’s what the X stands for. Defining it it’s left to you.

SPECIFICATION
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Includes Diezel iconic channels from VH4, Hagen, Herbert and more...
Fully digitally programmable controls: Gain, Channel, Bright, Shape, Voice, Middle, Treble, Bass, Midcut, Volume, Presence, Deep
Switchable Pre Loop
2 x Switchable FX Loop with independent programmable Send/Return Levels and Mix
XLR Balanced Cabsim DI or IR Loader Record Out
Headphones Cabsim DI or IR Loader Record Out
Cabless operation
Automatic chromatic Tuner
Up to 7 simultaneous fully programmable effects
Columbus MIDI support
Bluetooth Low Energy MIDI-BLE support
USB support
DOS 5.0 effects list: IR Cabsim, IR Loader, Noise Gate, Compressor, Quad/Capo/Pedal Pitch Shifter, Delay, Chorus, Flanger, Phaser, Reverb,
Tremolo, GEQ, PEQ, Rotary, Wah.
• No engineering degree required to operate the device :)3

VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dTABLE OF CONTENTSFRONT PANEL ............................................................. 5
REAR PANEL ............................................................... 6DISPLAY ..................................................................... 7
PREAMP ..................................................................... 8
FX .............................................................................. 9
FX SELECTION.......................................................................... 9
FX EDIT.................................................................................. 10
FX LIST .................................................................................. 10

CAB SIM ................................................................... 11
TUNER...................................................................... 12
STORE ...................................................................... 13
SETTINGS ................................................................. 14
MIDI ......................................................................... 15
UPDATE/IR LOADING ................................................ 16

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dFRONT PANEL
1 INPUT Connect your guitar here with a good quality ¼” Instrument

6 DISPLAY This is the Display where all the parameters will becable.

visualized. Each encoder will control the respective parameter on
display, following the lines.

2 PRE LOOP SEND Pre Loop SEND (output). Connect here the input
of one or a chain of effects. PRE LOOP is internally wired before the
PREAMP.

3 PRE LOOP RETURN Pre Loop RETURN (input). Connect here theoutput of the same effects used form PRE LOOP SEND. PRE LOOP isinternally wired before the preamp.

4 PRESET MANAGER Rotate the encoder to scroll between all theavailable presets, from 1 to 99. Push to open Preset Manager. HOLD
to quick store the preset.

5 ENCODERS This group of encoders will let you edit, by rotating,pressing, or holding the relative function shown on DISPLAY. Follow
the lines.

7 SCREEN MANAGER / MUTE Rotate the encoder to scroll between
all the available screens. Push the encoder to MUTE or UNMUTE the
POWER AMP to connected cabinets. POWER AMP cannot be
UNMUTED if no cabinet is connected.

8 MASTER VOLUME This is the POWER AMP Master Volume, it only
affects POWER AMP so connected cabinets.

9 STANDBY SWITCH Make sure the switch is on STANDBY mode
before powering on the VHX. Let the tube warm up for at least 40
seconds.

10 POWER SWITCH Make sure STANDBY is set to OFF before
powering ON the VHX. Before powering OFF the VHX set STANDBY
switch OFF and wait at least 30 second to avoid POWER AMP bump.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dREAR PANEL
11 AC IN Connect to a PROPERLY GROUNDED AC power outlet. Make
sure the voltage shown matches with the location you are using VHX
in.

12 COLUMBUS Connect your COLUMBUS controller here.
13 MIDI IN Connect your MIDI controller here. Please note that
PHANTOM POWER is available at 9V DC on pin 1-6 (-) and 3-7 (+) witha maximum 500mA current.

14 MIDI THRU Connect other chained MIDI devices here.
15 USB Connect with a PC for updates and presets backup. Avoid

LOOP or HUM, you could use the LIFT push button. AVOID connection
with 48V PHANTOM POWER enabled device.

17 HEADPHONES Connect your headphones here. This output could
be used in parallel to XLR REC OUT and POWER AMP. Adjust LEVEL andother settings trough the CAB SIM screen.

18 FX LOOP A/B Connect your effects chain here. FX LOOP A and FXLOOP B are completely independent and wired after the PREAMP and
could be placed anywhere in the integrated DSP EFFECT chain. Each
one has independent SEND, RETURN and MIX level adjustments,
controlled trough FX LOOP A/B effect screen section.

using USB HUB for reliable operation.

19 SPEAKER OUT Connect your CABINET(s) here. Make sure that the

16 REC OUT This is the CAB SIM Balanced XLR output. It could be used

IMPEDANCE of the CABINET(s) matches the one shown on the relative
output jack. MAKE SURE THE JACK IS CONNECTED ALL THE WAY IN
TO AVOID DAMAGE.

in parallel to HEADPHONES and POWER AMP. Adjust LEVEL and othersettings trough the CAB SIM screen. If you are experiencing GROUND

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dDISPLAY
The display is the heart of the VHX. It has been developed to give as
much as possible the feel and the simplicity of an analog UI.
Starting from the top, the navigation bar will display the POWER AMP
MUTE STATUS and the current SCREEN:
PREAMPFXRECORDTUNER
STORE
SETTINGSThe SIDES display the parameters relative to the current screen, and could be edited by rotating, pushing or holding the relative ENCODER.

To open the PRESET MANAGER, push the preset knob. Preset Manager would give an overview of all the current presets, with the gain and effects
associated with. It would be possible to select, move and copy/paste the presets to arrange them easily.
The PRESET MANAGER screen allow GLOBAL DEEP, GLOBAL PRESENCE, GLOBAL DI, GLOBAL MASTER and GLOBAL TAP to be edited. The parameters
are relative to the PER PRESET ones, where the value “0” means no change.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dPREAMPThe VHX preamp is the result of 25 years of constant development andinnovation, and it brings you all the ICONIC Diezel tones from the amps
everybody’s in love with: VH4, Herbert, Hagen, Paul and more…

GAIN Rotate the relative encoder to select the amount of gain.
GAIN STRUCTURE Push the GAIN encoder to scroll between all theavailable configurations: GREEN, YELLOW, BLUE and RED.

BRIGHT (For GREEN and YELLOW) Rotate the relative encoder totoggle bright mode.
SHAPE (For BLUE and RED) Rotate the relative encoder to scroll
between all the shape mode. Shape control will morph the relative
gain structure, from TIGHT to FAT.

VOICE (VINTAGE/EARLY/CLASSIC/MODERN) Push the SHAPE encoder to scroll between the available voices.
TREBLE - MIDDLE - BASS Rotate the relative encoder to adjust preamp EQ.
VOLUME Rotate the relative encoder to adjust preamp volume.
BOOST Push the relative encoder to enable +3db volume boost. This parameter could be remotely controlled with the MIDI CC6.
MIDCUT Rotate the relative encoder to adjust the midcut intensity, centred at about 400hz.
PRESENCE - DEEP Rotate the relative encoder to adjust POWERAMP presence and DEEP. Please note that PRESENCE and DEEP parameters affect
the CABSIM as well.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dFX
FX SELECTION
One of the most interesting features of the VHX is the integrated DSP.
It is placed between the PREAMP and POWERAMP, allowing for up to
7 simultaneous and completely programmable effects.
Each available SLOT is numbered from 1 to 6 except for the PRE LOOP,
labelled L as the position is fixed before the PREAMP.

TO ENABLE PRE LOOP Push the relative labelled encoder.
TO ASSIGN FX TO A SLOT rotate the relative numbered encoder toscroll between all the available FXs.

TO EDIT FX PARAMETER, push the relative numbered encoder toenter FX EDIT screen.

TO BYPASS FX, hold the relative numbered encoder.
MOVE Push the relative encoder to SWAP FX position between SLOTS: PUSH to enable the MOVE mode. ROTATE to move the blinking indicator
to the effect you need to move. PUSH to confirm the selection. ROTATE to move the selected FX to the new SLOT. PUSH to confirm.
LONG PUSH to CLEAR all effects.

CLEAR ALL Long Push to remove all the effects.

The signal path is SERIAL, and it is as follow:
PRE LOOPPREAMP

FX 1

FX 2

FX 3

FX 4

FX 5

FX 6

CABSIM

POWERAM9VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dFX EDITFX Edit screen let you edit selected effect parameters, by rotating the relative encoder. Push the EFFECT NAME encoder to return to FX SELECTION
Screen. LONG PUSH the EFFECT NAME encoder to TOGGLE BYPASS. Some parameters (i.e. DELAY TIME, PITCH) do have a FINE and COARSE mode.
Push the relative parameter encoder to toggle between the two modes.

FX LIST
Below the effect list and the relative parameters.

CHORUS Speed, Depth, Feedback, Modulation, Tone, Level.
COMPRESSOR Sustain, Attack, Release, Blend, Level.
DELAY A / B Time (MIDI CC#2), Feedback, Depth, Modulation, Tone, Level, Subdivisions, TAP, Mode (TAPE, ANALOG, DIGITAL)EQUALIZER 80 Hz, 350 Hz, 850 Hz, 3.5 KHz, 6.6 KHz, Bandwidth, Level.
PEQ A/B Mode (LOWPASS, HIGHPASS, BELL, L-SHELF, H-SHELF), A/B Frequency, A/B Gain, A/B Bandwidth

FLANGER Speed, Depth, Feedback, Level.
LOOP A / B Mix, Send Level, Return Level.
NOISE GATE Threshold, Attack, Release, Decay.
PHASER Speed, Depth, Feedback, Level.
PITCH SHIFT Mode (QUAD, CAPO, PEDAL), Pitch, Mix, Pitch A, Pitch B, Pitch C, Pitch D, Pitch Mix, Level, Pedal, Range.
REVERB Mode (PLATE, ROOM, HALL, SPRING, SHIMMER, LUSH), Predelay, Decay, Tone, Level.
TREMOLO Speed (MIDI CC#2), Depth, Slope, Subdivision, TAP.
ROTARY Speed (MIDI CC#2), Depth, Slope, TAP.
WAH Auto/Decay, Range, Q, Mix, Pedal (MIDI CC#68).
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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dCAB SIM
The integrated DSP does provide an IR based cabinet simulation as
well. Specifically developed for the VHX, it allows you to quickly
connect to FOH, without the hassle of configuring the microphones onstage.
CAB SIM could then be used in both CABLESS mode, without cabinet
or load, or in parallel with the POWER AMP with a connected cabinet.
Both HEADPHONES and XLR are controlled from the CABSIM screen
and could be used in parallel.
HEADPHONES and XLR supports DI mode, to be used with yourpreferred cabinet simulation hardware/software, or for reamping
purpose.

MODE Rotate the relative encoder to select DI mode, CAB mode, or IR LOADER mode.
SPEAKER Rotate the relative encoder to scroll between the available SPEAER: V30, G12K-100 or G12-65.
MIC Rotate the relative encoder to scroll between the available MIC: SM57, R121, C414, MD421.
POSITION Rotate the relative encoder to choose the MIC position relative to the speaker.
LEVEL Rotate the relative encoder to adjust output level. Please note that output level will affect both HEADPHONES and XLR.
HIGH Rotate the relative encoder to adjust the highcut filter response.
LOW Rotate the relative encoder to adjust the lowcut filter response.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dTUNERThe VHX integrated tuner will let you check and setup your instrument
quickly. It does feature an automatic mode to pop-up in the preamp
screen, very handy for studio or recording session. To enable it, strum
any string and leave it ringing for a couple of second.

Tuner screen could also be enabled with MIDI Control Change
message CC 1.
Please note that tuner settings are GLOBAL and not per preset.

440Hz Rotate the relative encoder to adjust tuner reference.
AUTO Rotate the relative encoder to toggle automatic tuner.
MODE (SLOW/FAST) Adjust the needle speed

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dSTOREThe STORE screen allows to store the current preset, preset name anddisplay colour.
If the current preset has been MODIFIED from the previous state, the
STORE icon on the navigation bar will show a RED DOT.

STORE Push the relative encoder to store the current preset, together
with name and display colour.

STORE TO # Rotate the relative encoder to select a different preset
location. Push the relative encoder to store to the new preset location.

CASE Push the relative encoder to toggle between LOWERCASE and
UPPERCASE.

DELETE Push the relative encoder to delete the last character fromthe preset name.

SELECT Rotate the relative encoder to MOVE the selector over the
displayed keyboard. Push the relative encoder to add the selectedcharacter.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dSETTINGS
The settings screen allows you to edit VHX global settings and it gives
information about the DOS (Diezel OS) version installed.

MIDI Rotate the relative encoder to select the MIDI channel. Please
note the it does affect all the MIDI input channels, so Columbus, BLEMIDI and USB MIDI.

BLUETOOTH Rotate the relative encoder to toggle the Bluetooth.
MUTE Select what mute will affect, GLOBAL (PA + CABSIM) or POWER
AMP only.

COLOR Select the spectrum analyser color between GRAY and
CHANNEL color (GREEN, YELLOW, BLUE, RED) or CHANNEL 2 color(GREEN, ACQUA, BLUE, PURPLE).

USB Push to MOUNT the VHX internal storage as USB MSC unit. Push again to UNMOUNT. Please note that while the USB is mounted the VHX UI
is locked.

OFFSET Select if presets numbers should start from 0 or from 1.
TAILS Select if DELAY and REVERB tails should be active when switching to presets with those effects not enabled.
RESET Hold to RESET the VHX to default. WARNING: Doing so all your preset will be DELETED.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

d

MIDI
The VHX is fully MIDI capable. MIDI could be used via the MIDI IN, COLUMBUS, USB MIDI or via Bluetooth Low Energy MIDI-BLE.
MIDI CHANNEL is selected via the SETTINGS screen, as well as OMNI mode.
Supported MIDI MESSAGES are PROGRAM CHANGE messages will select the current preset, from 0 to 99 and CONTROL CHANGE messages
that could control various function of the VHX, where toggle supports direct state as well, CCX 0 = OFF, CCX 1 = ON, any other value will toggle:
CC 1 Toggle POWER AMP MUTE andenables TUNER screen.
CC 2 TAP TEMPO Global
CC 3 TAP TEMPO for DELAY A
CC 4 TAP TEMPO for TREMOLO
CC 5 TAP TEMPO for DELAY B
CC 6 PREAMP VOLUME +3db BOOST
CC 7 MASTER VOLUME value.
CC 8 PREAMP VOLUME value.
CC 9 MID-CUT value.
CC 10 PREAMP VOICE value.
CC 11 PREAMP BRIGHT value.
CC 12 PREAMP SHAPE value.
CC 16 Toggle ALL FX and PREAMP LOOP.
CC 17 Toggle PREAMP LOOP.
CC 18 Toggle FX 1.

CC 19 Toggle FX 2.
CC 20 Toggle FX 3.
CC 21 Toggle FX 4.
CC 22 Toggle FX 5.
CC 23 Toggle FX 6.
CC 24 Toggle LOOP A
CC 25 Toggle LOOP B
CC 26 Toggle NOISEGATE
CC 27 Toggle COMPRESSOR
CC 28 Toggle PITCH
CC 29 Toggle DELAY
CC 30 Toggle CHORUS
CC 31 Toggle FLANGER
CC 32 Toggle PHASER
CC 33 Toggle TREMOLO
CC 34 Toggle REVERB

CC 35 Toggle GEQ
CC 36 Toggle WAH
CC 37 Toggle DELAY B
CC 38 Toggle ROTARYCC 64 Delay A Level.
CC 65 Delay B Level.
CC 66 Delay A Feedback.
CC 67 Delay B Feedback.
CC 68 Wah Pedal.
CC 69 Pitch Shift Pedal.
CC 70 Loop A Send Level
CC 71 Loop B Send Level.
CC 96 Select current PC+1
CC 97 Select current PC-1
CC 119 RESERVED

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

dUPDATE/IR LOADINGThe VHX could be easily accessed using the USB connector located on the BACK PANEL together with a PC, MAC or USB OTG capable smartphone.
Once connected, MOUNT the USB mass storage via the SETTINGS screen. It will appear to the OS as an MSC DEVICE, and the internal memory will
be accessible just like a regular disk.
To LOAD CUSTOM IR on VHX:CONNECT the VHX to a PC or USB OTG capable smartphone.
MOUNT the VHX USB via SETTINGS screen.
COPY the ir files (44.1K to 96K) in the folder IR inside the VHX disk. IR will be sorted alphabetically.

To UPDATE the VHX, please make sure that all the connections and power supply are stable and reliable, and follow the steps below:
DOWNLOAD the latest available software from www.diezelamplification.com support page.
POWER ON the VHX.
CONNECT the VHX to a PC or USB OTG capable smartphone.
MOUNT the VHX USB via SETTINGS screen.
COPY the file named DOS.bin in the VHX disk root.
POWER OFF the VHX.
POWER ON the VHX and wait for the update to finish. DO NOT power off the VHX during these last steps.

In case of any FAILURE, the VHX will enter in RECOVERY MODE, please follow the above steps again to recover.
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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

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VHX DOS 5.04 OWNER’S MANUAL. © 2021 Diezel GmbH. All rights reserved.

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