Allen & Heath XONE VF-1 User Guide

ALLEN&HEATH

User Guide

For standard version VF-1 and RIAA version VF-1R

Publication AP5917

XONE VF-1 User Guide AP5917 Issue 2

Copyright © 2004 Allen & Heath Limited. All rights reserved

Whilst we believe the information in this guide to be reliable we do not assume responsibility for inaccuracies.
We also reserve the right to make changes in the interest of further product development.

This product complies with the European Electromagnetic Compatibility directives
89/336/EEC & 92/31/EEC and the European Low Voltage Directives 73/23/EEC &
93/68/EEC.

This product has been tested to EN55103 Parts 1 & 2 1996 for use in Environments E1, E2, E3, and E4 to
demonstrate compliance with the protection requirements in the European EMC directive 89/336/EEC. During
some tests the specified performance figures of the product were affected. This is considered permissible and
the product has been passed as acceptable for its intended use.

Allen & Heath has a strict policy of ensuring all products are tested to the latest safety and EMC standards.
Customers requiring more information about EMC and safety issues can contact Allen & Heath.

NOTE: Any changes or modifications to the unit not approved by Allen & Heath could void the compliance of
the unit and therefore the user’s authority to operate it.

ALLEN&HEATH

Manufactured in the United Kingdom
Allen & Heath Limited
Kernick Industrial Estate, Penryn, Cornwall, TR10 9LU, UK

http://www.allen-heath.com

2 XONE VF-1 User Guide

Important Safety Instructions – Read First

Read instructions: Read and retain these instructions for future reference. Read the instructions on the Safety Sheet

provided separately. Adhere to all warnings printed here and on the console and its power unit.

Cover: Operate the unit with its cover correctly fitted. Refer servicing work to competent technical personnel

only.

Mains power: Connect the unit to a mains power supply only of the type described in this user guide and marked

on the unit. The power source must provide a good ground connection. Do not remove or tamper
with the ground connection in the power cord. Use the power cord with sealed mains plug
appropriate for your local mains supply as provided with the unit. Route the power cord so that it is
not likely to be walked on, stretched or pinched by items placed upon or against it.

Installation: Install the unit in accordance with the instructions printed in this user guide. Do not connect the

output of power amplifiers directly to the unit. Use audio connectors and plugs only for their intended
purpose.

Ventilation: Ensure adequate ventilation around the unit. Do not obstruct the ventilation slots or position the unit

where the air flow required for ventilation is impeded.

Moisture: To reduce the risk of fire or electric shock do not expose the equipment to rain or moisture or use it in

damp or wet conditions. Do not place containers of liquids on it which might spill into any openings.

Environment: Locate the unit away from direct sunlight and any equipment which produces heat such as power

supplies, amplifiers and heaters. Protect from excessive dirt, dust, heat and vibration when operating
and storing. Avoid tobacco ash, drinks spillage, and smoke, especially that associated with smoke
machines.

Handling: To prevent damage to the controls and cosmetics avoid placing heavy objects on the unit surfaces,

scratching the surface with sharp objects, or rough handling and vibration. Protect the controls from
damage during transit. Use adequate packing if you need to ship the unit.

XONE VF-1 User Guide 3

Important Note on Mains Voltage Setting

The internal power unit has a universal mains voltage input able to operate within the range
100V to 240V.AC 50/60Hz. Ensure that your local mains voltage is within this range. Check
that you have been supplied with an IEC mains lead fitted with a moulded mains plug suitable
for your local supply.

Important Mains Plug Wiring Instructions

The unit is supplied with a moulded mains plug fitted to the AC mains power lead. Follow the
instructions below if the mains plug has to be replaced.

The wire which is coloured Green/Yellow or Green must be connected to the terminal in the
plug which is marked with the letter E or with the Earth symbol.

This appliance must be earthed.

The wire which is coloured Blue or White must be connected to the terminal in the plug which
is marked with the letter N.

The wire which is coloured Brown or Black must be connected to the terminal in the plug which
is marked with the letter L.

Ensure that these colour codes are followed carefully in the event of the plug being changed.

4 XONE VF-1 User Guide

Contents

Important Safety Instructions .....................................................3

Front and Rear Panel Drawings .................................................6

Welcome to the XONE VF-1 ......................................................7

Front Panel Controls ..................................................................8

Rear Panel Controls .................................................................12

Rear Panel Connectors ............................................................13

Audio Cables............................................................................15

Grounding ................................................................................16

Installing the Unit......................................................................19

MIDI ..........................................................................................20

Setting the MIDI Channel Number ...........................................21

Using MIDI to Link VF-1 Units .................................................. 22

Using MIDI to Connect a Sequencer or Controller ..................23

MIDI Control Codes..................................................................24

MIDI Implementation Chart ......................................................26

Technical Specification ............................................................28

System Block Diagram............................................................. 29

User Notes (blank page) ..........................................................30

XONE VF-1 User Guide 5

SERIAL No:

VF-1

ENV-FOLL TO OVERDRIVE

5

6

4

3

2

1

7

SLOW

8

9

FAST

10

0

DECAY WAVEFORM

THIS APPARATUS MUST BE EARTHED
WARNING: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE
ATTENTION: REMPLACER LE FUSIBLE AVEC UN DES MEMES CARACTERISTIQUES.

5

4

5

6

4

3

2

1

VALVE OVERDRIVEENVELOPE FOLLOWER

FUSE

100

50-60Hz~
10W MAX

T500mA L
250V 20mm

7

8

9

4Hz

0.8

OFF

ON

REPLACE FUSE WITH SAME TYPE AND RATING

16

0.2

LFO

MIDI

8

INOUT

MADE IN ENGLAND BY ALLEN & HEATH Ltd

5

4

3

2

1

LFO DEPTH

LOCAL

OFF

MONITOR OUT

6

7

8

9

100

3

2

1

LEFT RIGHT

BALANCED OUT

6

7

0

9

10

ANALOGUE STEREO FILTER

8

JACK OUTPUT

MIX+INVERT FILTER

LEFT

OUTPUT

RIGHT

UNBALANCED

IN

RL

OUT

VCF FREQUENCYHI-PASS BAND-PASS LOW-PASSRESONANCE

USE LEFT I/P 24dB/OCT

LEFT

RIGHT

INPUT

MONO

BALANCED IN

20kHz20Hz

LEFT RIGHT

FILTER ON

12dB/Octave stereo
24dB/Octave mono
with Valve Overdrive

6 XONE VF-1 User Guide

Welcome to the

The XONE VF-1 is a high quality 1U rack analogue filter unit
featuring an enhanced version of the legendary VCA filter circuit
used in our award winning XONE mixer range.

Three different filter types are provided, high-pass, band-pass
and low-pass. These can be selected together to create further
types, for example high-pass and low-pass together produce a
notch filter. The filter frequency can be swept either manually or
automatically in several different ways to create stunning or subtle
performance effects.

A resonance control adjusts the sharpness of the filter from a
gentle roll off to a peaky maximum reminiscent of the distinctive
sound of the classic analogue synthesiser. The ARC (automatic
resonance control) monitors the output of the filter to
automatically reduce the resonant peaks of high level signals so
avoiding potentially system damaging transients. For further
protection all the filter controls are “soft switched” to prevent
clicks during performance.

Using a rear panel switch the filter can be configured as 2-pole
stereo 12dB/octave or 4-pole mono 24dB/octave without the need
to re-patch. Another rear panel switch can sum the inverted filter
signal with the non filtered input to create cancellation effects
providing some unusual and subtle sounds, especially when
routed to an external effects unit such as reverb or delay.

progressively increased to create musically pleasing second
harmonic distortion. This is a great tool for adding warmth to a
mix or for fattening up thin bass sounds. Automatic gain
reduction circuitry maintains a near constant output level as the
overdrive control is increased.

An envelope follower with switchable release time allows the filter
cut-off frequency to be modulated by the intensity of the input
signal. This can be used to create some interesting effects,
particularly with drum loops and bass lines, or be switched into
the valve circuit to give intensity modulated overdrive.

A wide range LFO (low frequency oscillator) with square/triangle
waveforms completes the modulation toolbox for the filter system.

The VF-1 can send and receive MIDI allowing the filter frequency,
type and on/off status to be remotely controlled or saved to a
sequencer. It can be configured to operate in several different
modes to interface to our MIDI equipped Xone:92 DJ mixer, a
sequencer, or to track the filters to MIDI notes.

The VF-1 is equipped with a wide range of input and output
connectors including balanced XLR, TRS jack and RCA phono
with optional RIAA preamp, making it easy to connect to almost
any system. A dedicated monitor output is provided to allow the
filtered sound to be previewed before switching in the effect.

As well as the VCA filter the VF-1 also features a valve (tube) input
stage with drive control. The signal level though the valve can be

XONE VF-1 User Guide 7

Whether you are a serious DJ or a professional production studio
we hope you enjoy using the uniquely powerful XONE VF-1.

Andy Rigby-Jones, the designer

Front Panel Controls

3

5

7

0.8

OFF

8

9

ON

4

1

ENV-FOLL TO OVERDRIVE

5

6

4

3

2

1

7

SLOW

8

9

0

FAST

10

DECAY WAVEFORM

5

6

4

3

2

1

VALVE OVERDRIVEENVELOPE FOLLOWER

100

2

6

4Hz

8

16

0.2

LFO

4

3

2

1

LFO DEPTH

5

6

7

9

100

87

4

3

2

8

1

0

1

Envelope Follower

The envelope follower modulates the filter cut-off frequency in
direct proportion to the intensity of the input signal. For example,
with low-pass filter selected and set to a low 20Hz, turning up the
envelope follower will produce a dynamic effect as the filter cut-off
frequency rises and falls along with the loudness of the music.

2

Envelope Follower Decay

Sets the decay speed of the envelope follower, either slow or fast.
This changes the sound of the effect according to the type of
music played.

11

12

139

5

6

7

8

9

10

ANALOGUE STEREO FILTER

VCF FREQUENCYHI-PASS BAND- PASS LOW-PASSRESONANCE

20kHz20Hz

FILTER ON

12dB/Octave stereo
24dB/Octave mono
with Valv e Overdrive

10

3

Valve Overdrive

Turn this up to increase the amount of signal passing through the
valve (tube) stage. This increases the second harmonic distortion
and valve compression effect created which produces a pleasing
‘fattening’ of the sound. At minimum the signal is low enough to
ensure that the valve is operated in its linear region with little
effect. Continuing to increase the level of overdrive will first cause
the valve to “soft clip”, ideal for music sources, and then bring in
“hard clip” circuitry making the effect much more pronounced,
better suited to changing the character of instrument sounds such
as a bass line. The control includes a ‘make-up gain’ element
which controls the ratio between input and output level so that the
volume does not seem to increase too much as the overdrive, and
therefore distortion/compression effect, is increased.

8 XONE VF-1 User Guide

4

Envelope follower to overdrive

8

Resonance

Enables the envelope follower circuit to modulate the valve
overdrive so that the valve distortion/compression effect increases
dynamically with the music. Produces a subtle, interesting effect..

5

LFO Speed

Sets the speed at which the LFO (low frequency oscillator) will
modulate the filters, from a slow 0.2Hz (approximately 12BPM) to
a very fast 16Hz (960 BPM).

6

LFO Waveform

Selects the type of waveform that the LFO outputs to modulate the
filter. A triangle output will smoothly sweep the filter cut-off
frequency up and down, whilst a square wave will produce an
instant cut-off frequency change rather like a “gating” effect.

The resonance control alters the way the filter behaves at its cut­off frequency. With the control at minimum the filter will have a
gentle roll-off and therefore a smooth, subtle sound. At maximum
the filter will have extra gain at its cut-off frequency, greatly
emphasising any sound at this frequency.

Care should be taken when using the filter unit with the resonance
set at maximum as it may cause clipping in the signal path.
However the VF-1 includes an automatic resonance control (ARC)
circuit that reduces the amount of resonance at high signal levels
so minimising the likelihood of distortion. Also, the ARC circuit will
automatically reduce the amount of resonance at low frequencies
where there is higher energy level and therefore greater chance of
damage to low frequency speaker drivers.

When the two VF-1 filters are combined as a single mono
24dB/oct unit the amount of resonance will be doubled.

The diagram below shows the effect around the filter cut-off
frequency of increasing the resonance.

RESONANCE

HIGH

MID

7

LFO Depth

Adjusts the level (or depth) of LFO modulation. Set anti-clockwise
for no effect, turn clockwise to increase the effect.

XONE VF-1 User Guide 9

0dB

CUT-OFF POINT

20Hz

FREQUENCY 20kHz

LOW

9

Hi-Pass

Turn on the high-pass filter to progressively remove low
frequencies below the cut-off selected using the VCF
FREQUENCY control [12]. The switch illuminates when the hi­pass filter is active. The diagram shows the response as the
frequency control is rotated. It also shows the boost around the
cut-off frequency when resonance is increased.

+20

+15

+10

+5

0dB

-5

-10

-15

-20

HI-PASS FILTER

LO

HI

10k20 1kHz100 20k

10

Band-Pass

Turn on the band-pass filter to progressively remove frequencies
above and below the cut-off selected using the VCF FREQUENCY
control [12]. The switch illuminates when the band-pass filter is
active. The diagram shows the response as the frequency control
is rotated. It also shows the boost around the cut-off frequency
when resonance is increased.

11

Lo-Pass

Turn on the low-pass filter to progressively remove high
frequencies above the cut-off selected using the VCF
FREQUENCY control [12]. The switch illuminates when the low­pass filter is active. The diagram shows the response as the
frequency control is rotated. It also shows the boost around the
cut-off frequency when resonance is increased.

+20

+15

+10

+5

0dB

-5

-10

-15

-20

+20

+15

+10

+5

0dB

-5

-10

-15

-20

BAND-PASS FILTER

LO

LO-PASS FILTER

LO

HI

10k20 1kHz100 20k

HI

10k20 1kHz100 20k

10 XONE VF-1 User Guide