Symetrix 564E User manual

Quad Expander/Gate
Operating Manual
mm
Version 1^0
Mav 1^991
.• .'.'0
c1991 Symetrix, Inc.
4211 24th Ave. West Seattle, WA 98199 USA Telephone 206*282*2555 Fax 206>283<5504

Table of Coot
Section Page
1. Introduction 1
1.1 Product Description 1
1.2 Control of Dynamic Range with Expanders and Gates 1
1.3 Threshold 1
1.4 Expanders and Ratio 2
1.5 Gates and Range 2
1.6 Frequency Conscious Gating 2
2. Using the 564E 3
2.1 Block Diagram 3
2.2 Installation 4
2.3 Signal Levels 4
2.4 Front Panel Controls and Switches 5
2.5 Rear Panel Connections 6
3. Fast First Time Setup 8
3.1 Connections 8
3.2 Switch Settings 8
3.3 Rotary Control Settings 8
3.4 Meter Readings 8
4. Applications 9
4.1 Introduction 9
4.2 Noise Elimination 10
4.3 Tightening Up Drums 1
1
4.4 Preventing False Triggering 12
4.5 Console Sub-Outs 13
4.6 Effects Returns 14
4.7 Vocal Monitors 15
5. Troubleshooting 16
6. Specifications 17
7. Appendix—Hipass &Lopass Filter Roll-Off 18
8. Service Information 19
9. Limited Warranty 20
10. 564E PCB Layout and Schematics 21

INTRODUCTION
Tliank you ior pUR'h;isinf> ihc Symclrix 5(mE. Tlif Ibllowinj; intbniwtion in this imniuil
may help you achieve optimum pertbnnance from your Quad Expander (>ale Entcessor.
The S(hE Quad Expander Gale has lieen desijjned to the hijjhesi pn)fessional slan-
dards for use in fixed or mobile sound systems. The use of anify>ed .steel chassis,
tlouhle sided printed circuit boards, toroidal power transfomier. and industrial grade
eleciro/mechanical components ihrougltout the SChE enable the prcKluct to provide
years of ilependable .serx’ice in any and all profes.sional audit) applications.
'X'hile the sb tE is easy to install and u.se it will greatly lienelil the u.ser to lake the lime
nece.ssarx' to read this entire manual. However, if you're going to jump right in and
start using the ^(hE wiihttui reading the manual plea.se. just take aminute to run
through the East First Time .Set I'E -Section
Any comments on our products or this manual aa- more than welcome.
1-ach of the four ciianneis may lx- iiulividually operaietl in GATE or EXPander moile.
balanced or unbalancet.1 signals may lx- applied to the XI.E .style input connectors. To
further expand the %iE's functional [X)s.sibilities, acontrol l<H>p (send and reiurni is
included for ilevices like delay lines and graphic equali/ers (for enhancement of
fix'(|uency .sensitive operation). This allows .special enecis and manipulation of prob-
lem audio sources,
Wide range frt>m panel control allows extensive signal manipulation to .solve problems
found in both .studio and live environments. With all controls Ix-ing fully variable, the
level of perfonttance you are able to extract from the S() lE de[x-n<.ls eniia-ly on your
understanding of these controls. E»)r this reason, the following pages include atutorial
.section to aid in understanding the various functions available from the A(>iE.
1.1
Product
Description
when ^lealing with audio signals, the term •dynamic range' de.scrilx's actual level
changes, or the range over which signals fluctuate. The dynamic range of the human
voice, from awhisper to a shout is well over l(K)<.lb. So amientphone will convert the
sound pressure of avoice going fn)m awhisper to ashout into an ekvlrical output
signal with adynamic range of well over lOOdH.
Expansion and gating are both vlerived from the same signal puR'essing family of gain
reduction. The heart of this pnx'ess is based on amplifier circuitrv' in which the gain is
dependent on the signal level pas.sing through it. These ampliflers are known as VC^A's
(Voltage Controlled Amplifier), by changing the gain, based on signal conditions, the
dynamic range of that signal can lx- automatic-ally altered.
1.2
Control of
Dynamic
Range with
Expanders and
Gates
The threshold is the level at which adynamic range pnHes.sor's activity begins. In
operation, the dynamic range proces.sor's sen.sing circuitrv' constantly 'looks' at the
incoming signal and compares it to arelerc-nce level, which is called the threshold
iroini. Kemember. expanders and gates respond only when signals at the input aa'
lower than the defined threshold.
1.3
Threshoid

1.4
Expanders
&Ratio
Adownward expander may lx- ihouglii of a.s adevice whicli causes auiomalic gain
reduction Moiv some definable signal level. In oilier words, an expander can he
l(K)ked upon as the 'opposite' of acompre.s.sor limiler.
r.xpanders typically operate at low ratios. Al.so, it is im|iortant to keep in mind that the
ratio of an expander is the numix-r of dll's of decrea.se in input level compared to the
numher of dB’s of decrease in the output signal. At 1:,^. klB of decrease Iheiow
threshold) at the input causes a.V.IIJ decrease at the output.
1.5
Gates &
Range
Gates can lx- thought of as high niiio (around 1:20) expantlers. They are iniendetl to
sluil out undesired signals that fail Ix-low ihreslmkl. I'.se the Kh^' input to create
special elfects. (See General Applications in Section t).
1.6
Frequency
Conscious
Gating
The KhY l.ISTKN. IIII’ASS and I.OI'ASS controls together provide afeature whicli is
commonly referred to as "ITei|uency Gon.scious Gating". Fxpanders and gati's ai'i' built
from two basic circuit elements: ( 1 ) the Voltage Conimlled Ampliller IVCAI Im h
causes the actual changes in the audio level and (2) the Cainlrol Loop whii his iiasi-
cally alittle analog computer that lotiks' at the incoming amlio, the luser's lotiiml
panel sc-ttings, ami then tells' the VGA what to do.
In afret|uency con.scious expander or gale, laipass and Ilipass controls Lin- .idiled to
the Control Uxip in order to re.slricl the range of fret|uencies fed to the an.ilog u>nv
puter. Uy doing .so the expander or gtile can lx- told to lx- very .selective .iIhhii whicli
.sounds it is triggered by. The.se signals are .sometimes referred to its Kl-V sign.ils
which is just another n;ime for trigger. Hence, the front panel switch whuii .illnws you
to listen to the.se signals is lalx-Iled 'KHV LIS TI-'N'.
l-'or exampk-—Let’s s;iy afull tlrum kit is being recordetl. Amicrophone li.i' Ken
ptisitioned above the head of atl<Hir tom. Achannel of tlie S6 tl'. has been inserteil into
the console input channel for that microphone. The ^(hK is set in gate nuHle hnthe
purj-xise of removing leakage from acymbal which is in close proximiiv ti <tin ll> mr
tom. Keen with the directional mic positioned to reject a.s much cymiiLil as (sisMble the
S(mK gate 'opens' when the drummer strikes either the lltxir tom or cynib.il 1in-
engineer now pushes the S(hK's KHY LISTHN switch allowing him to lisu-ti a.ilu-
CON'I'KOL LOOP audio. (This is \OT the gated signal—just the audio Ih-imu ted iu the
analog computer!) He tunes the HIPASS and I.OPASS controls until the oml'.il i' iiiiK-il
out and he Is hearing primarily the tlmir tom. This is now the signal the an.ilog lom-
puter will use to decide when to turn the gale on ami oif after the KH')' I.IS'I'IK sw itch
is relea.sed to nonnal position.
2
um

nuoN
2. USING THE 564E
2.1 Block
Diagram
This functional block
diagram illusirates the signal
How into, inside of, and out
of the 564E The levels and
impedance at the INPUTS
and OUTPUTS are designed
to match all common line
level systems. All conneaors
arelocatedon the rear panel,
all switches andcontrols arc
located on the front panel.
In the blodc diagram, control
and switch names arc
enclosed with abox.
3

2.2
Installation
2.3
Signal Levels
Tlic is designed for mounting in astandard 19" rack and recjiiircs only one rack
space (lU). The 564Es INPUTs. OlTIUTs. and CONTROL LOOFs should he wired to
apaicli hay for ease of operation. Asugge.sied arrangement for unbalanced operation
witli amono paichixiy is shmvn Ik-Iow. If the 564F. is used with apatchbay, the
connections from the control Uk>p must go to normalled jacks.
Top row
toulpuls)
'normalized' to
bottom row
(Inpulsi.
The is designed to tv used po-sl-preamp. at aplace in the system where the
signals haw already Iven amplified to line levels. 'Line level' is ageneric lemi that's
been used at one lime or another to descritv signals ranging anywhere Irom
tOdHV to +2()dHV. As aix-siill there's really no way for us to predict wlial the actual
operating levels in your .sy.siem will Iv. The ftOdH range of the %I's THKK.SHOl.l)
control allows you to make it work will) awide range of line level input signals.
Miemphone and guitars, for example, are not line level and should not he plugged
directly into the Doing so will not damage the unit, Init will result in excessive
noise.
The overall level in any signal chain is determined to alarge extent hy the transient
content of the program material. Tninsienis are ver\ .sliort duration signals. Peak
reading LED type meters will usually resjxmd to transients, lull VT meters are de.signeil
to indicate average levels ami thea'fore will not respond to transients. As aresult,
transients are long gone Ivloa- aVI meter can a-spond.
Drums, and [vreussive insirumenis like piano or hanjo. generate the kitul ol veiy large
transients which aa* not sliown hy a\'l 'meter. Signals from these instruments may
trigger the sf>iE when llie I'l IRI'SI lOLD control is set at +10 even though your \'l
meter says ilie level never g<vs alxive O'. (If precise metering ol'shori transient peaks
is neccessaiy for your needs. Symeirix" digital SX20tI’recision Audio Meter will meet
the most demanding situations.) On the oilier hand, instruments like violins do not
ereale large transients, so the eorrelalion Ivtween llie VT meter abiding and the
indicatetl tlia’.shold appears to Iv more accurate.

2.4 FRONT PANEL CONTROLS &SWITCHES
r.
r.
Xj
•r.
C
V
c.
c
c
c
r.
•r.
\r.
<
r.
sc
SC
c
f-
i7
<
•/.
c
sc
c.
5
d)
GATE/EXPAND
-
Deleniiinos
whether
the
5
(hK
operates
as
either
an
expander
lci<x;kwise)
or
a
jtale
lcoiinter-c!<Kkwise).
'I'he
expander
ratio
is
increased
as
the
control
is
rotated
ckK'kwise.
The
gate
range
is
increased
as
ilte
control
is
rotated
counter-clockwise.

1
6
®
CONTROL
LOOP
-
This
connc’clor
is
unusual,
and
should
lx.-
.siudicd
tartTully.
Rear
panel
space
con.sirainis
require
ihe
use
of
a
single
1
R.S
(tip-rin>{-
sleeve)
connector
for
both
the
in
out
SIDIiCHAIN
access
to
the
VGA's
contr*)l
l<K)p.
and
for
e.xiernal
('key')
input
signals.
This
jack
accepts
1
4"
3-
conduclor
(stereo
type)
plugs
(Sxvitchcnift
“292
or
equixalent).

2.5 REAR PANEL CONNECTIONS
c
tj
cu
£i
D—
V2
2-5
c
fau
V
>J;
A
C
V. r?
^-z
•i £
c
c
c
'S.
P
2.S ^
e. V5
£
'D c=
I
^i^
rs «
I
i= s
“SC V
5-7 2
ii ^
•SPo
e^o
$CO m
wCO
r**
Q
w
>:
w/
L/
P“
78-2
I5
e°^
^©-
In
situations
where
the
56-*E
drives
an
unbalanced
h>ad
pin
3
must
be
grounded.
The
balanced
output
source
impedance
of
the
564F.
is
200U.
The
minimum
load
impedance
is
600U.

1
3. FAST FIRS
3.1
Connections
I'olkjw ihis .sequcncL- lo gci (he %-4F: up and nmninj>:
INPUT •Conned lo ihe ouipui of the si>>nal source to Iv processc-tl.
OUTPUT -Conned lo ihe input of the Idllowinj; device.
CONTROL LOOP (OPTIONAL) •Connect lo and Irom external proce.ssinn (l-.Q, key
driver audio trucks), etc.
The I.KD meter on each channel will n«il lijjhl when the GATH HXP conirol is centered.
34The meler i.s pcnik reading and will accur.ilely track the atlenuaiion of the VCA (voltajje
Meter Reaclinns eomrolled amplifier). Mower RK1.KASK limes will kcvp the lllelerin^ i.HD's li>>hled
"longer Ivcausc’ they inick ihe control voltage as it's applied to the VCA.
Note
Although the 564E's meter wilt not showany activity when the GATE/EXP
control is In it's center position, we do not recommend this control
position as a method of bypassing GATE/EXP action. Small amounts of
gain reduction (less than 2dB) may occur with no indication on the meter.
Use the Bypass switch to bring the signal out of the 564E circuitry.

14. APPLICATIONS
The can provide produilion signal prix'essing capabilities ranging from essential
to e.soieric. Some of the techniques descrilx*d Ix'low are .standard and .straightforxvard.
Others may be u.setl less commonly but are hopefully worthy of your investigation.
The following 'patche.s' are intended to give you .some setups you can use right tiway.
but are not intended to repa-seni everything you can do with the ^(hK.
4.1
Introduction
I'erhaps the most common use for gates in music production is on drum and peaxis-
sion tracks. In addition gtites may lx- used on virtually any type- of nuisiail iasiniment
or audio sound elTect to remove unwanted rtxim noise and ambience, to modify
TL-viTh iincl uiIkt limt- rclaicci dYccus. and to crcau.- .special elVecis.
Adownward cxpamicr is similar to a^alc Inil there are some major dilTerences. Most
noteworthy is this: Wlien asignal I'aMs Ix-low aset thre.shold on agale, it falls to a
predetermined level as set l>y the RANGH control. Not so when u.sing adownward
expander. Since we are now dealing with aRATIO setting instead t>f HANGh. the
allemialion is still variahle even wlien it falls Ixrlow lha-shold. In other words the %-iK
will still follow the dynamic moveiiieni of the signal no matter how far the .signal
t)io\ es helow ihresiiold. This makes the KXRand mode ideal for tasks reciuiring more
Militle control. lxpalHlers can provide single-ended noise rc-duciion for tape recorders,
work.siations. and effects devices, companding (when used with acompressor in
situations that lio not require accurate tracking), and noi.se and interference suppres-
sion for.siiitlio and live sound.
Note
The shaded areas shown on the knobs In the following application
descriptions indicate the range of settings most commonly us^ for that
particular Job.
Switches in depressed mode (not mood) are indicated with gray shading.
l-or easy access, each of the applications descrilx'd in this seiiion begins on its own
page. We recommend that you use the empty .space for your own notes,

4.2
Noise
Elimination
It's ;is.siinKtl here that there's noise on the track or cliannel tltai liecoines objectionable
when not masked by the desired sij»nal. Use GATK mode, witli the TMKHSHOl.D .set
alxjve the backftroiind level, but just l>elo\v the level ol' llie desia-d signal. Tlie jtate
clo.ses whenever the -signal falls below threshold, so only the desired signals are
allowed U) pass.
MODE GAIN REDUCTION (-dB)
^40 20 12 g63
WOOOOOO
200 IK
3
-10 _
+20 FAST SLOW -60dB 1:3
THRESHOLD RELEASE GATE EXP
(x)nirol sellings for n«ii.se elimination in GA I'H okkIc.
MODE GAIN REDUC'nON (-dB)
40 20 12 9 6 3
OOOOOO
0
FAST SLOW -60dB 1:3
RELEASE GATE EXP
Control -settings f«)r noise elimination in HXPand mode.
For moa- general and gentle noLst- suppression (especially tin voice tracks) use the
KXHand iiHKie. and set the niRK-SIlOU) relatively l<nv.
10

The d;impin{> elt'ecl you get hy taping your wallet to the drum lieacl i> very similar lo
tile etTeet achieved liy gating or expanding the drums. Tlie wallet reduces the tiecay
(sii-siain) of the iastaimenl, and helps gel rid of annoying ring fret|iiencies. Using the
gale as an electronic wallet allows the drummer lo play with the full power of his
instmmenls at live performance levels, while providing the engineer with the kind of
control necessar\' for a gooil, tight track.
Careful adju.simenl of HXPAM) or GATF. functions allows the relative halance 1k--
Iween the drum's impact and decay lo lx- changed. You can reduce the overhang
(decay) as much, and as (|iiickly. as neces.sar>-; shortening the decay makes the
impact noise amuch moa- prominent component of the total sound.
MODE GAIN REDUCTION l-dB)
40 20 12 96 3
WOOOOOO
-10
-40 4-20
THRESHOLD
0
FAST SLOW -60dB 1:3
RELEASE GATE EXP
Stan witli the sellings indicated, anti lx- prepared for serious Mne tuning. The GATF
KANCiH will alTecl the AlTA(iK and KFI.FA.SK so use as much attenuation as needed,
hut no more than necessary. FAST A'lTACK TIMK will sometimes ca-ate an audihle
uirn-on click. .Sometimes the click can lx- used to enhance the percussive effetl of the
.sound. .st)metimes it's not desirable. Tr\' SLOW ATTACK TIMF il necessary.
NOTE
The ability of the EXPANDER/GATEto dtscriminate between wanted and
unwanted signals Is determined in partby mlc technique. Beparticularly
careful when high frequency Instruments are located to the side or rear
of acardlokt mlc. Most cardiolds exhibit asharply rising off-axis
response characteristic at higher frequencies. If there’s only a 2 dB or 3
dB difference betvreen the on-axis and off- axis response in the 5kHz to
10 kHz region, cymbals may leak like crazy Into your tom mics, and you
may have hi-hat all over the snare mlc. Use the mic’s directional pattern
to keep other sources as far off-axis as possible. Remember -the idea
Is to do everything you can to extract all the sour^to source
discrimination possible through good mictechnique. The sounds picked
up by the individual mIcs have to be primarily the sound of the individual
drums, or the gate won’t be able to tell the difference.
4.3
Tightening Up
Drum Sounds
11

4.4
Preventing
False Triggering
by Hi-hat and
Kick While
Gating aSnare
I( d<K;.sn’l matter if it's live or in the -studio—s(»melimes you just ilon'l have as many
mies as you would like for your drum -selup. Typically one of the first places acom-
promise is made is on the snare and hijjh-hai. Well .we can just use one mic for
l>olh..- riftlit? This Ls all line and well if there is no concern for hleed-ihrouHh. but if
you want to jjate the snare drum, the chances are lx‘iier-than-}i(M)d that the hi-hat is
j’oinf’ to f>ive your patience amn for the money when it comes to seitinj} the threshold
without fai-se triBj>erinj{ by the hi-hat.
This example will show you the basic priKedure to applyinj> the Iiipass and l.opass
fillers to ytatinyt asi}»nal. It's alittle bit of a"tweaky" procedure as the filters are some-
what interactive with the Attack and Tlireshold controls but the extra effort is well
worth it-
KEY ATTACK
LISTEN FAST
NORM
200
SLOW
IK
IN
OUT
-10
MODE GAIN REDUCTION (-dB)
40 20 12 96 3
oooooo
0
3020 FAST SLOW -eOdB 1:3
THRESHOLD RELEASE GATE EXP
Stan otf with the Hipa.ss filler in the full counter-clockwise position and ihe Utpass
filler in the full clockwise po.siiion. The remaining comntls are set as shown above.
Maw the dminmer play iu.si the snare and hi-hat. Adjust the Thre.shold to allow gating
to occur teven though the hi-hat may trigger the gate at this point).
Now push in the Key Listen switch. Rotate the l.opass filter control Uj it’s full counter-
clockwise position. Porall practical purposcLs. the hi-hat .should be much less audible
and the snare should Ik- amuffied *thud.'
Release the Key Listen switch to it's NORM position. You may have to re-adjusl the
Threshold control slightly at this point. The snare should be gated now without any
false triggering by the hi-hat.
With the Key .switch still in NORM mode, have the ilrummer play the snare again, but
this time with kick accompaniment- If the kick tlrum is triggering the snare gate rotate
the Hipass control cltKkwise until the gate no longer triggers by the kick drum.
12

Two Sf>4K's am urcatly improve tlie over-all .signal-lo-noise nilion of sound re-enforee-
meni eonsoles. One could jusi j>ule the final output of the iKKird. hut with the llexihil-
ity of four channels of either jiutiny «)r downward expansion available on aS(>*K. a
cost effective meth<Kl of eniovin^ anoise-free sound system is at your finf>er tips
without j’aiin}’ every individual cinmnel.
4.5
Sound
Re-enforcement
Console
Sub-Outs
Most of the consoles on tlie road out there are of the eijihl Mihj;roup ouipui \’arieiy.
Assign each subgroup output to one channel of the AfHE's. When the subs are carrying
afast transient signal like drums or percussion, use the gale mode with the appropriate
attack and release litnes.
MODE GAIN REDUCTION (-dB)
40 20 12 9 6 3
WOOOOOO
-10 0
-40 -f20 FAST SLOW -60dB 1:3
THRESHOLD RELEASE GATE EXP
On other sub-outs that are tiedicatetl to softer signals like \<k;iIs use- slower release
times when gating or use downward expansion.
13

4.6
EFFECTS
RETURNS
One oftlie most overl<K>kecl noise sourevs in alull sound re-enlbreemenl or recoRiinj>
system is tlte signal prinessing racks. Tlie very nature of compressors and limiters
raises the apparent noise lltatr of asignal as the dynamic range is squa.shed. Devices
like reveries, delay lines. Iiamionizer. etc. have come down drastically in price over the
la.si years .so they are now common uk)1s in .small studios and liome recording sel-ups.
lInfortunately, as neat as alot of these toys are. its all too easy to end up with pntcess-
ing in your rack that sounds ga-ai hut the signal-to-m>i.se ratio is less than desirable.
Sometimes one would listen to aprtK'essing device and say "Well that’s pretty quiet.”
—hut it's collective ntti.sc* that is the culprit. Once you have live, .six or more pieces of
gear running, you can easily end up with an ohjectionahle noi.se lloor.
Try patching the %4K Ix'tween the KFX outputs and the HPX RHTUKN.S on the console.
I'se the S6lH in it's KXI’anil nuxle as shown below. .Slower Release times are prelei-
ahle here to retain the natur.il decay times of reverhs etc.
QD'’* KEY AHACK MODE
LISTEN
NORM
200
FAST
SLOW
IK
IN
OUT
•10
GAIN REDUCTION (-dB)
40 20 12 963
oooooo
0
30K -40 -f20 FAST SLOW -BOdB 13
THRESHOLD RELEASE GATE EXP
14
idwiij

Here's one of the golden uses of the 5(v>E—increasing gain anti cleaning up the main
vcK'al mic in stage monitor systems. Again, prepare yourself for alittle fine timing, hut
you sound guys in cluhs with medium size stages will he plea.sed you took the time.
First set up the in the KXl’and mode as shown helow with afairly fast release
lime. The threshold .sliould lx- set to trigger on nomial level speech.
Next, with the switch in listen mode, nrll off some of the high frequencies. Tliis
will lake care of alot of drum cymixil leakage. In small to medium size club stages it is
not uncommon for the center mic .singer to Ik’ jiust 2-4 feet in front a the tirum .set
hashing away directly hehintl him lokay... or her). If you wish, apply some roll-olf to
the lows. This will help prevent the downwanl expander from triggering if the singer
likes to rock the mic stand.
(iet hack to the NORM mode and do your final tha-.shold adjustments as well as
any filter fine tuning.
You may prefer to use the CiATE motle if the EXE motle is not enough signal attenua-
tion for you.
KEY ATTACK MODE
LISTEN
NORM
200
FAST
SLOW
IK
IN
OUT
-10
GAIN REDUCTION (-dB)
40 20 12 9 6 3
OOOOOO
D000
30 4K 150 30K -40 *20 FAST SLOW -SOdB 1:3
HIPASSyC:'-::i^0PASS threshold RELEASE GATE EXP
30
4.7
Vocal Monitors
15

5. TROUBLE SHOOTING I
PROBLEM POSSIBLE CAUSE
NO SOUND AT Does the meter show attenuation? If so check your threshold setting, as
OUTPUT it may be too high to ever let any signal through.
Are all connections solid and correct? (99.9% of all problems in the audio
field are due to wiring and patching!)
Threshold too high?
NO APPARENT Release time is set to long?
EFFECT FROM GATE Hipass filter is set fully clockwise while Lopass filter is set fully counter-
clockwise. (The VCA thinks the signal has been nulled out to the point it
is considerably below threshold minimum, [see appendix on page 16]
)
Bypass switch is not depressed?
Key insert not normalized?
Preceding device output level is too hot?
DISTORTION AT Preceding device is distorting?
OUTPUT ‘Hot 'points of balanced output connector cables are shorted.
Key listen switch is pushed in.
OUTPUT SOUNDS
COLORED OR EQ'D
16
Ill'iB

6. 564 SPECIFICATIONS
S/N Ratio 92 dB at OdBv in, OdBv out
Dynamic Range IIOdB
THD .03% OdB g/r
at 1kHz, into 600£i .05% 10dB g/r
Freq. Response (+0dB, -IdB) 20Hz to 20kHz
Input Electronically balanced
Impedance >20kO
Max Input Level +18dBv Bal., +18dBv Unbal.
CMRR at 1kHz >40dB
Output
Impedance 2000 Bal., icon Unbal.
Max level into 6000 bal. +24dBm
Max level into 6000 Unbal. +18dBm
Control Loop Input (Key Input) Unbalanced
Impedance 30kO
Max Input +18dBv
Control Loop Output Unbalanced
Impedance 3000
Control Voltage Rejection
Measured at output svith 10OHz square
wave applied to key input
80dB
Threshold -40dBv to +20dBv
Expander Soft-knee
Attack (Fast) 50dB/2mS
Attack (Slow) 50dB/2mS
Release (Fast) 50dB/.7 sec
Release (Slow) 50dB/8.5 sec
Ratio 1:1 to 1:3
Max. Attenuation >50dB
Gate
Max. Attack 50dB/50uS
Min. Attack 50dB/200uS
Max. Release 50dB/2mS
Min. Release 50dB/3 sec
Range 0-60dB
Lopass/Hipass Filters
Response 12d6/octave
Frequency Response (fully open)
Hipass Filter Range 30Hz -30kHz 30Hz to 4kHz
Lopass Filter Range 150Hz to 30kHz
Crosstalk >90dB @20kHz
Power Requirements 117VAC. 140ma
220VAC. 70ma
Physical
Size Chassis: 1.7"H x17.4"W x 9.6 "D {4.3cm Hx45cm Wx24.4cm D)
Front Panel: 19"W x1.75“H (48.3cm Wx4.5cm H)
Shipping Weight 11 |bs (5kg)
All specifications subject to change. ©1991 Symetrix, Inc. 17

7. APPENDIX AHipass &Lopass Filter Roll-off I
AlookalTable7.i shows one
position of Hipass and Lopass
filter controls that will result in
redundancy: If you rotate the
Hipass control fully clockwise,
and the Lopass control fully
counter-clockwise, the signal
is almost totally filtered out of
the VGA's “eye."
With this setting, asignal
entering the 564E at OdB will
appear at a -45dB level at the
control circuit. This is below
the minimum threshold point
of the 564E so no signal
processing can occur.
;e/Lopass clockwise
Hipass counter-clockwi
Lopass/Hipass clock vise
counter-clockwise
Lopass/Hipass
Lopass count! r-dockwise/
Hipass dockiA ise
10k 30k
10.000
-10.00
-20.00
-50.00,
Bandpass vs Frequency
Input: 20Hz-30kHz sweep at Odb.
18
ilfiNli