Crown VFX-2 User manual

VFX-2
IM-1
ete
crown
INSTRUCTION MANUAL
SERIAL NO.
ISSUED TO:
VFX2
DUAL-CHANNEL
FILTER/CROSSOVER
CROWN
INTERNATIONAL,
INC.,
BOX
1000
ELKHART,
INDIANA
46514

TABLE OF CONTENTS
SECTION
Section 1
Section 2
Section 3
TITLE PAGE
INTRODUCTION
1.1 Scope of Manual
1.2. Equipment Description
1.3. Specifications ...
14 Warranty
INSTALLATION AND OPERATION
2.1
2.2
2.3
24
25
General ....
Unpacking .
Mounting
Installation
24.1 Cabling ...
2.4.2 Input Connections
24.3 Output Connections
244 Glossary of Filter Terms
Operation
occ
2.5.1 Control Functions ....
2.5.2 Setting Hi-Pass Hz Filter Frequency
2.5.3 Setting Lo-Pass Hz Filter Frequency
2.54
Setting
Controls
for
Bandpass
Filter
Operation
..
14
2.5.5
Mono
(Balanced)
Output
Application
......
CIRCUIT DESCRIPTION
3.1
3.2
33
34
General woe
Circuit Description ..
3.2.1 Filtering Circuits ..
3.2.2 Power Supply Circuits
Test Procedures
Service Policies

LIST OF ILLUSTRATIONS
FIGURENO. TITLE PAGE
1-1
VFX2
Dual-Channel
Filter/Crossover
...
wl
1-2
Typical
Frequency
Response:
IHF
Load
at
Rated
Output
3
1-3. Typical Phase Response: No Filters
1-4 Typical Phase Response: High and Low Pass Filters
1-5 % IM Distortion - All Controls Flat with IHF Load
1-6 Typical Filter Curves ...
1-7 Typical Maximum Output: IHF Load . ae
1-8 Typical Common Mode Rejection ......... aw 6
2-1 Mounting Dimensions
2-2
Typical
System
Configurations
and
Cables
.
w
@9
2-3.
Phone
Plug,
%",
3-Conductor
o...cccecceeeee
weld
2-4
Phone
Plug,
'4", 2-Conductor
......
2-5 Front Panel Controls
2-6 Rear Panel Controls and Commectors .....cccccscssssssscssessessessssssessncscsscsvessestevessesavsevancarsesans 12

SECTION 1
INTRODUCTION
REAR VIEW
FRONT VIEW
FIGURE 1-1
VFX2 DUAL-CHANNEL FILTER/CROSSOVER
1.1 SCOPE OF MANUAL
This manual is intended to provide the user
necessary technical information required to operate
the CROWN VFX2 Dual-channel Filter/ Crossover unit
properly and to maintain the unit in optimum
operating condition.
The manual is comprehensive, containing a physical
description of the VFX2, electrical and mechanical
specifications, complete installation and operating
instructions, a detailed circuit description, test
procedures and service policies. Also included are a
complete parts list and the associated VFX2
schematic to assist in identification of parts and
understanding the functional operation of the VFX2.
A thorough reading of this manual and strict
adherence to the instructions, procedures and
cautions will assure many years of professional
quality service and listening enjoyment from your
CROWN VFX2 Dual-Channel Filter/ Crossover.
1.2 EQUIPMENT DESCRIPTION
The CROWN Model VFX2 is a_ dual-channel
filter/ crossover unit specifically designed to provide
continuously variable filters to perform either high
pass/ low pass or bandpass functions in professional
or commercial sound, or home “‘hi-fi” applications.
The VFX2 is a compact, ruggedly constructed unit
designed to fit a standard 19” rack mount (W.E. hole
spacing) and occupies only 3%" of vertical rack
space. Maximum depth from the mounting surface is
5%". The chassis is all aluminum black and satinized
anodized and the entire unit weights only 6 pounds.
Front panel controls are four sets of range/vernier
knobs for the Hl and LOW PASS Hz setting of the
ilters in the two audio channels and a rotary POWER
ON-OFF switch.
Rear panel controls are a screwdriver-adjustable
LEVEL (attenuator) control and a mode switch for
selecting either CROSSOVER (low pass) or FILTER
(bandpass) outputs for each audio channel.
Rear panel connectors include a variable gain
bridging input for each channel! in addition to the
unity gain unbalanced input. Output connectors,
both high pass and low pass, are provided for
inverted and non-inverted (NORMAL) modes. An AC
ine fuse to protect the unit and the power
transformer are also located on the rear panel.

1.3 SPECIFICATIONS
Frequency Response
Phase Response
Output
Inputs
Gain
Hum and Noise
Distortion
Filters
Semiconductor
Complement
Power Requirements
Fusing
Controls
Connectors
Chassis Finish
Dimensions
Weight
VFX-2
Dual Channel Variable Electronic Filter-Crossover
+0.1dB 20Hz to 20KHz with IHF load
Typically +0.2dB 2Hz to 58KHz with IHF load,
+0.5dB 18Hz to 38KHz with 600 2 load
All tests with filters flat and at rated output. (See graph)
See graph.
10V Maximum before overload, 2.5V rated
50
2
output
impedance
accepts
600
2
load
(typically
6.4V
maximum
into
600
@
)
All outputs available in normal (non-inverted) and inverted modes.
Two types per channel:
Transformerless bridging input with 4" phone jack or attenuator, 20K ohm bal-
anced, 10K ohm unbalanced
OR
Unity gain input 4” phone jack, 1M ohm unbalanced. For balanced input common
mode rejection see graph.
0-15.5dB from balanced/ unbalanced input
More than 100dB below rated output with OdB gain, 20Hz to 20KHz.
All tests with filters flat.
IM distortion less than 0.01% at rated output.
IHF or 6002 with filters flat or set at 20Hz and 20KHz (See graph).
Separate 18dB Butterworth Highpass and Lowpass Filters with adjustable corner
frequencies. Can be internally cascaded to form band pass and band reject
filters. (See graph)
10 integrated circuits (20 operational amplifiers equivalent to 400 transistors and
40 diodes) for a total of 402 transistors, 2 zeners and 56 diodes.
2 Watts 120 VAC or 240 VAC 50-400Hz
For 120 VAC use 3 AG 1/8 Amp 250 VAC fuse
(For 240 VAC use AGC 1/16 Amp 250 VAC fuse)
Range and vernier controls for corner frequencies and power switch are on
front panei.
Screwdriver-adjustable input attenuator on rear panel.
Inputs — 3 conductor 4" phone jack balanced/ unbalanced
2 conductor 4" phone jack unbalanced unity gain
Outputs — 2 conductor ’” phone jack
AC line — Three wire (grounded) male connector on 5 ft. minimum cable
All aluminum black and satinized anodized
19” standard rack mount (W.E. hole spacing), 3%" height, 5%” maximum depth
(from mounting surface)
6 Ibs.

1.4 WARRANTY
cluded
with
this
manual.
The
WARRANTY
is
subject
to
the
conditions
contained
therein.
Upon
receipt
of
the
registration
form,
CROWN
will
issue
a
WAR-
RANTY
TITLE.
This
title
applies
to
the
original
end-
purchaser
as
well as
subsequent
purchasers.
CROWN
guarantees
this
equipment
to
perform
as
specified.
CROWN
also
warrants
the
components
and
workmanship
of
this
equipment
to
be
free
from
defects
for
a
period
of
3
years
from
date
of
purchase.
This
warranty
does
not
extend
to
fuses,
and/or
com-
You,
the
purchaser(s),
are
responsible
for
accurate,
ponent
or
equipment
damage
due
to
negligence,
complete
records
(sales
slips,
invoices,
etc.)
for
FULL coverage!
misuse,
shipping
damage
or
accident;
or
if
the
serial
, altered or removed.
A
copy
of
the
FULL
THREE-YEAR
WARRANTY
is
in-
number has been defaced
1db
Odb
-2db
1Hz
10Hz
100Hz
1KHz
10KHz
100KHz
1Hz
FIGURE 1-2
TYPICAL
FREQUENCY
RESPONSE:
IHF
LOAD
AT
RATED
OUTPUT
DEGREES
in
=
-15°
-30°
1Hz
10Hz
100Hz
1KHz
10KHz
100KHz
THz
FIGURE 1-3
TYPICAL PHASE RESPONSE: NO FILTERS

DEGREES
360°
in
a
tt
a
a
]
180°
90°
0°
I
fee
oS
po
a
90°
-7180°
-270°
-360°
LHz
10Hz
100Hz
1KHz
10KHz
100KHz
MHz
FIGURE 1-4
TYPICAL
PHASE
RESPONSE.
HIGH
AND
LOW
PASS
FILTERS
% iM
-0010
100V
10V
1v
1V
-01V
FIGURE 1-5
— ALL CONTROLS FLAT WITH IHF LOAD
IM DISTORTION
%

2 3
-20db
1Hz 10Hz 100Hz 1KHz 10KHz 100KHz
-1Hz
10db
-
Sa
aaa
|
setates,
Odb
-10db
-20db
1Hz 10Hz 100Hz 1KHz 10KHz 100KHz
-1Hz
FIGURE 1-6
TYPICAL FILTER CURVES
So =
1Hz 10Hz 100Hz 1KHz 10KHz 100KHz
Hz
7
TYPICAL MAXIMUM OUTPUT; IHF LOAD
FIGURE 1

Yn
‘i
{
|
|
-
des
SLaoemiape
aera
nota
(abet
ate
ae
ts
Seis
Pal
a
sr
ten
anes
s
Soe
ae
ee
(occa
Sees
iceman
:
:
;
i
60db
70db
80db
90db
100db
110db
120db
1Hz 10Hz 100Hz 1KHz 10KHz 100KHz
Hz
FIGURE 1-8
TYPICAL COMMON MODE REJECTION

2.1 GENERAL
This
section
contains
information
for
unpacking
the
unit,
reporting
procedures
for
damaged
shipments,
mounting
instructions,
cabling
diagrams
for
various
operational
modes
and
a
description
of
control
functions
and
settings.
2.2 UNPACKING
Immediately
upon
receipt
of
the
VFX2
shipment,
inspect
the
unit
for
any
damage
incurred
in
transit.
The
unit
was
carefully
inspected
and
tested
and
left
the
factory
unmarred.
Notify
the
transportation
company
immediately
if
any
damage
is
found.
Only
the
consignee
may
initiate
a
claim
with
the
carrier
for
damage
during
shipment.
However,
CROWN
will
cooperate
fully
in
such
an
event.
Be
sure
to
save
the
carton
as
evidence
of
damage
for
the
shipper’s
inspection.
CROWN
recommends
that
you
save
the
packing
materials,
even
if
the
unit
arrives
in
perfect
condition.
They
will
prove
valuable
in
preventing
SECTION 2
INSTALLATION
AND
OPERATION
damage
should
there
be
occasion
to
transport
or
ship
the
unit.
Both
the
carton
and
internal
pack
are
specifically
designed
for
protection
during
transit.
Do
not
ship
the
unit
without
this
factory
pack!
2.3 MOUNTING
The
VFX2
is
specifically
designed
for
standard
19”
rack
mounting,
but
may
be
custom
mounted
if
suf-
ficient
support
is
provided.
Refer
to
Figure
2-1
for
mounting
dimensions.
Supplied
with
the
VFX2
is
a
decorative
smoked
acrylic
overlay.
The
overlay
functions
as
a
protective
shield
preventing
the
front
panel
control
settings
from
being
accidentally
bumped.
The
VFX2
can
be
mounted
to
the
rack
or
cabinet
by
using
the
10-8
adapter
stud
supplied.
The
overlay
then
fits
over
the
stud
and
is
secured
by
black
dress
nuts.
cy
D-----+
in
alalaialaate
3172"
3
&
|
Bowe
enters
foc
|.
Ja
3/8"
is"
8
3a"
(STANDARD
RACK
MOUNT
} (
MAX.
DEPTH
FROM
MOUNTING
SURFACE)
FIGURE
2-1
MOUNTING
DIMENSIONS