Orban OPTIMOD-FM 8200 Operating Manual
Operating Manual
OPTIMOD-FM
8200
Digital Audio Processor
®
IMPORTANT NOTE: Refer to the unit ’s rear panel for your Model #.
Model Number: Description:
8200/U3S OPTIMOD-FM 8200 DIGITAL with three DSP cards, Stereo Encoder,
Protection Structure, Two-band Purist Structure, Two-band Normal
Structure, Multi-band Processing Structure, set to 115V (for 90-130V
operation), switchable to 50µs or 75µs.
8200/E3S OPTIMOD-FM 8200 DIGITAL with three DSP cards, Stereo Encoder,
Protection Structure, Two-band Purist Structure, Two-band Normal
Structure, Multi-band Processing Structure, set to 230V, (for 180-260V
operation), switchable to 50µs or 75µs.
OPTIONS A VAILABLE:
Model Number: Description:
CIT25 Composite Isolation Transformer.
8200D/32 Digital I/O Card, 32kHz
8200 PC Remote Control Software for IBM PC compatible computers
MANUAL:
Part Number: Description:
95100-301-01 8200 Manual (includes 8200 PC Manual)
CAUTION: TO REDUCE THE RISK OF ELECTRICAL S HO CK , DO NO T REMOVE COVER (OR BACK).
NO USER SERV I CE A B LE PARTS I NS I DE . REFER SERVICING TO QUA LIFIED SERVICE P E RS ONNEL.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHO CK,
DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.
This symbol, wherever i t appears , This symbol, wherever i t appears ,
alerts you to the presence of unins ul ate d alerts you to important operat ing and
dangerous voltage inside the enc los ure — volt age maintenance instruc tions i n the ac c ompany in g
that may be suff ic i ent t o constitute a risk of shock. literature. Read the manual.
All the safety and operating instructions should be read before the appliance is operated.
Retain Instructions:
The safety and operation instructions should be retained for future reference.
Heed Warnings:
All warnings on the appliance and in the operating instructions should be adhered to.
Follow Instructions:
All operation and user instructions should be followed.
Water and Moisture:
The appliance should not be used near water (e.g., near a bathtub, washbowl, kitchen sink, laundry tub, in a wet
basement, or near a swimming pool, etc.).
Ventilation:
The appliance should be situated so that its location or position does not interfere with its proper ventilation. For example, the
appliance should not be situated on a bed, sofa, rug, or similar surface that may block the ventilation openings; or, placed in a built-in
installation, such as a bookcase or cabinet that may impede the flow of air through the ventilation openings.
Heat:
The appliance should be situated away from heat sources such as radiators, heat registers, stoves, or other appliances (including
amplifiers) that produce heat.
Power Sources:
The appliance should be connected to a power supply only of the type described in the operating instructions or as
marked on the appliance.
Grounding or Polarization:
Precautions should be taken so that the grounding or polarization means of an applianceis not defeated.
Power-Cord Protection:
Power-supply cords should be routed so that they are not likely to be walked on or pinched by items placed
upon or against them,paying particular attention to cords at plugs,convenience receptacles, and the point where they exit from the appliance.
Cleaning:
The appliance should be cleaned only as recommended by the manufacturer.
Non-Use Periods:
The power cord of the appliance should be unplugged from the outlet when left unused for a long period of time.
Object and Liquid Entry:
Care should be taken so that objects do not fall and liquids are not spilled into the enclosure through
openings.
Damage Requiring Service:
The appliance should be serviced by qualified service personnel when:
The power supply cord or the plug has been damaged; or
Objects have fallen, or liquid has been spilled into the appliance; or
The appliance has been exposed to rain; or
The appliance does not appear to operate normally or exhibits a marked change in performance; or
The appliance has been dropped, or the enclosure damaged.
Servicing:
The user should not attempt to service the appliance beyond that described in the operating instructions. All other servicing
should be referred to qualified service personnel.
The Appliance should be used only with a cart or stand that is recommended by the manufacturer.
Safety Instruct ions (European)
Notice For U.K. Customers If Your Unit Is Equipped With A Power Cord.
WARNING: THIS APPLIANCE MUST BE EARTHED.
The cores in the mains lead are coloured in accordance with the following code:
GREEN and YELLOW - Earth BLUE - Neutral BROWN - Live
As colours of the cores in the mains lead of this appliance may not correspond with the coloured markings identifying the terminals in your
plug, proceed as follows:
The core which is coloured green and yellow must be connected to the terminal in the plug marked with the letter E, or with the earth symbol,
( ), or coloured green, or green and yellow.
The core which is coloured blue must be connected to the terminal marked N or coloured black.
The core which is coloured brown must be connected to the terminal marked L or coloured red.
The power cord is terminated in a CEE7/7 plug (Continental Europe). The green/yellow wi re i s connected direc tl y to the unit ’s chassis. If
you need to change the plug and if you are qualified to do so, refer to the table below.
WARNING: If the ground is defeated, certain f ault conditions in the unit or in the sys tem to which it is conne cted ca n result in full line
voltage between chassis and eart h ground. Severe injury or de ath can then re sult if the chassis and earth ground are touched simultaneously.
AC Power Cord Color Coding
IMPORTANT SAFETY INSTRUCTIONS
CONDUCTOR
WIRE COLOR
Normal Alt
L LIVE BROWN BLACK
NEUTRAL BLUE WHITE
EARTH GND GREEN-YELLOW GREEN
N
E
Safety Instruc tions ( G erm an)
Gerät nur an der am Leistungsschild vermerkten Spannung und Stromart betreiben.
Sicherungen nur durch solche, gleicher Stromstärke und gleichen Abschaltverhaltens ersetzen. Sicherungen nie überbrücken.
Jedwede Beschädigung des Netzkabels vermeiden. Netzkabel nicht knicken oder quetschen. Beim Abziehen des Netzkabels den
Stecker und nicht das Kabel enfassen. Beschädigte Netzkabel sofort auswechseln.
Gerät und Netzkabel keinen übertriebenen mechanischen Beaspruchungen aussetzen.
Um Berührung gefährlicher elektrischer Spannungen zu vermeiden, darf das Gerät nicht geöffnet werden. Im Fall von Betriebsstörun-
gen darf das Gerät nur Von befugten Servicestellen instandgesetzt werden. Im Gerät befinden sich keine, durch den Benutzer
reparierbare Teile.
Zur Vermeidung von elektrischen Schlägen und Feuer ist das Gerät vor Nässe zu schützen. Eindringen von Feuchtigkeit und
Flüssigkeiten in das Gerät vermeiden.
Bei Betriebsstörungen bzw. nach Eindringen von Flüssigkeiten oder anderen Gegenständen, das Gerät sofort vom Netz trennen und
eine qualifizierte Servicestelle kontaktieren.
Safety Instruct ions (Fr ench)
On sassurera toujours que la tension et la nature du courant utilisé correspondent bien à ceux indiqués sur la plaque de lappareil.
Nutiliser que des fusibles de même intensité et du même principe de mise hors circuit que les fusibles dorigine. Ne jamais shunter les
fusibles.
Eviter tout ce qui risque dendommager le câble seceur. On ne devra ni le plier, ni laplatir. Lorsquon débranche lappareil, tirer la fiche
et non le cäble. Si un cäble est endommagé, le remplacer immédiatement.
Ne jamais exposer lappareil ou le cäble ä une contrainte mécanique excessive.
Pour éviter tout contact averc une tension électrique dangereuse, on noouvrira jamais lappareil. En cas de dysfonctionnement,
lappareil ne peut être réparé que dans un atelier autorisé. Aucun élément de cet appareil ne peut être réparé par lutilisateur.
Pour éviter les risques de décharge électrique et dincendie, protéger lappareil de lhumidité. Eviter toute pénétration dhumidité ou fr
liquide dans lappareil.
En cas de dysfonctionnement ou si un liquide ou toutautre objet apénétré dans lappareil couper aussitôt lappareil de son alimentation
et sadresser à un point de service aprésvente autorisé.
Safety Instructions ( Spanish)
Hacer funcionar el aparato sólo con la tensión y clase de corriente señaladas en la placa indicadora de características.
Reemplazar los fusibles sólo por otros de la misma intensidad de corriente y sistema de desconexión. No poner nunca los fusibles en
puente.
Proteger el cable de alimentación contra toda clase de daños. No doblar o apretar el cable. Al desenchufar, asir el enchufe y no el
cable. Sustituir inmediatamente cables dañados.
No someter el aparato y el cable de alimentación a esfuerzo mecánico excesivo.
Para evitar el contacto con tensiones eléctricaspeligrosas, el aparato no debe abrirse. En caso de producirse fallosde funcionamiento,
debe ser reparado sólo por talleres de servicio autorizados. Enel aparato no se encuentra ninguna pieza que pudiera ser reparada por
el usuario.
Para evitar descargas eléctricas e incendios, el aparato debe protegerse contra la humedad, impidiendo que penetren ésta o líquidos
en el mismo.
En caso de producirse fallas de funcionamiento como consecuencia de la penetración de líquidos u otros objetos en el aparato, hay
que desconectarlo inmediatamente de la red y ponerse en contacto con un taller de servicio autorizado.
Safety Instructions (Italian)
Far funzionare lapparecchio solo con la tensione e il tipo di corrente indicati sulla targa riportante i dati sulle prestazioni.
Sostituire i dispositivi di protezione (valvole,fusibili ecc.) solo con dispositivi aventi lo stesso amperaggio e lo stesso comportamento di
interruzione. Non cavallottare mai i dispositivi di protezione.
Evitare qualsiasi danno al cavo di collegamento alla rete. Non piegare o schiacciare il cavo. Per staccare il cavo, tirare la presa e mai
il cavo. Sostituire subito i cavi danneggiati.
Non esporre lapparecchio e il cavo ad esagerate sollecitazioni meccaniche.
Per evitare il contatto con le tensioni elettriche pericolose, lapparecchio non deve venir aperto. In caso di anomalie di funzionamento
lapparecchio deve venir riparato soloda centri di servizio autorizzati. Nellapparecchionon si trovano partiche possano essereriparate
dallutente.
Per evitare scosse elettriche o incendi, lapparecchio va protetto dallumidità. Evitare che umidità o liquidi entrino nellapparecchio.
In caso di anomalie di funzionamento rispettivamente dopo la penetrazione di liquidi o oggetti nellapparecchio, staccare immedi-
atamente lapparecchio dalla rete e contattare un centro di servizio qualificato.
PLEASE READ THIS FIRST!
Manual
The Operating Manual contains instructions to verify the proper operation of this unit and initialization of certain options.
You will find these operations are most conveniently performed on the bench before you install the unit in the rack.
Please review the Manual, especially the installation section, before unpacking the unit.
Trial Period Precautions
If your unit has been provided on a trial basis:
You should observe the following precautions to avoid reconditioning charges in case you later wish to return the unit to
your dealer.
Note the packing technique and save all packing materials. It is not wise to ship in other than the factory carton. (Replace-
ments cost $35.00).
(1) Avoid scratching the paint or plating. Set the unit on soft, clean surfaces.
(2) Do not cut the grounding pin from the line cord.
(3) Use care and proper tools in removing and tightening screws to avoid burring the heads.
(4) Use the nylon-washered rack screws supplied, if possible, to avoid damaging the panel. Support the unit when
tightening the screws so that the threads do not scrape the paint inside the slotted holes.
Packing
When you pack the unit for shipping:
Tighten all screws on any barrier strip(s) so the screws do not fall out from vibration.
Wrap the unit in its original plastic bag to avoid abrading the paint.
Seal the inner and outer cartons with tape.
If you are returning the unit permanently (for credit), be sure to enclose:
•
The Manual(s)
•
The Registration Card
•
The Line Cord
•
All Miscellaneous Hardware (including the Rack Screws)
•
The Extender Card
•
The COAX Connecting Cable
Your dealer may charge you for any missing items.
If you are returning a unit for repair, do not enclose any of the above items.
Further advice on proper packing and shipping is included in Section 5: Troubleshooting.
Trouble
If you have problems with installation or operation:
(1) Check everything you have done so far against the instructions in the Manual. The information contained therein is
based on our years of experience with OPTIMOD and broadcast stations.
(2) Check the other sections of the Manual (consult the Table of Contents and Index) to see if there might be some
suggestions regarding your problem.
(3) After reading the section on Factory Assistance, you may call Orban Customer Service for advice during normal
California business hours. The number is (1) 510/351-3500.
®
MAINTAINING 8200 SECURITY
Important: Ensure 8200 se curity by making it standard polic y for each 8200 user to manually
re-enable loc kout when finished with normal operation.
If your 8200 uses security pascodes and TIMEOUT TO AUTO LOCK is OFF (as set in the
SET
PASCODE
screen), the last s ucce ssfu l pas code e ntry de fines th e cur re nt secur ity le vel. U ntil locko ut
is re-enabled , subs equent us er s with a low er se curity level will ha ve acc ess to mor e func tion s than
they should.
Therefore, we recommend that each user re-enable lockout mode when finished with normal
operation. R e-en abling lo ckou t ens ur es that ea ch us er is a llowed to enter a p ascode to hav e acc ess
to the correct amount of functions for which their pascode was previously assigned.
If a previous user does for ge t to re- ena bl e l oc kout , sim pl y com pl e te the fo ll owi ng ste ps:
If the
IDLE G/R screen does not appear, press ESC repeatedly until you see it.
Hold down the ESC button, while pressing HELP button.
With 8200 lockout now re-enabled, enter a valid pascode and continue with normal operation.
®
Manual Addendum
8200 Version 3.0 Upgrade
For OPTIMOD-FM 8200 Digital
8200 Version 3.0 Manual Addendum
New Format Presets
Insert the following page, titled “New Format Presets In Version 3.00,” into
your 8200 Operation Manual, in Section 3, directly after the blue-tabbed
“About Processing Structures” page, at page 3-9.
There are 21 new format-specific presets, each named for a programming
format. There are two Urban/Rap presets, for instance, that add bottom-end
slam to the sound. Three new Rock presets add punch and sizzle while Adult
Contemporary and Country presets balance warmth and clarity, with up-front
vocals that stand out. There are also presets for Pop, Classical, Instrumental,
Jazz, Folk/Traditional, News, and Sports. There are even two Oldies presets
that ensure consistent sound balance with material from different eras.
Programmed by Bob Orban and Greg Ogonowski, each preset has full
LESS-MORE capability.
Multi-Band Controls
Insert the following “New Multi-Band Features For Version 3.00” pages into
your 8200 Operation Manual, in Section 3, at the end of the discussion on
“The Multi-Band Structure,” directly preceding the red-tabbed “Screen
Displays” page.
New controls include: High Frequency Coupling, Multi-Band Output Mix
controls, Bass Clip Threshold, and Phase Rotator In/Out. The range for the
existing Final Clip Drive has also been extended.
D-O Status Enable?
[Yes] or [No]
For 8200s equipped with the 8200 D/SRC, the 8200's controls now include a
switch that allows you to defeat Orban's special implementation of AES/EBU
status bits which are used to control Orban 8208 and 8218 Stereo Encoders.
This special implementation may be defeated to accommodate certain digital
STLs that misinterpret these status bits.
Beginning with V 1.20 software and revision 3.0 of the 8200D/SRC Digital
I/O board, the 8200 set the emphasis bits in the AES/EBU status bits (byte 0,
bits 2 through 4) accord ing to an Or ban p rop rietary standar d that extends the
AES/EBU official definition. The Orban standard allows the 8200 to
automatically set the 8218 (and 8208) Stereo Encoder's emphasis/deemphasis to complement the 8200's emphasis/de-emphasis.
I-2
MANUAL ADDENDUM Orban
Byte 0 Bits 2-4 AES/EBU Definition 8200 Implementation 8218 Response
000 not indicated not indicated applies FM pre-emphasis
001 undefined undefined doesn't alter emphasis
010 undefined undefined doesn't alter emphasis
011 undefined undefined doesn't alter emphasis
100 no emphasis no emphasis applies FM pre-emphasis
101 undefined J.17+FM pre-e* applies J.17 de-emphasis
110 50/15µs FM pre-e* doesn't alter emphasis
111 J.17 J.17 applies J.17 de-emphasis
and FM pre-emphasis
* FM pre-emphasis is 50 or 75µs
Since the implementation of the Orban standard, some digital STLs were
released that misinterpret these status bits. Some respond to the AES/EBU
emphasis bits (110) by applying an EIAJ (50/15uS) shelving de-emphasis.
This will cause an audible (10.5 dB) loss of high frequencies. Version 3.00
software allows the user to enable- or disable the Orban implementation of
status bits. When disabled, the 8200 sends status bits identifying that
emphasis is “not indicated,” which ensures that the affected digital STLs will
not inappropriately apply EIAJ de-emphasis.
When these digital STLs are used in combination with an 8200 and 8218 (or
8208), DO STATUS ENABLE must be set to No, and the 8218 (or 8208),
cannot utilize the “AES determines emphasis” feature.
PC Security Enable
[On] or [Off]
The OPTIMOD 8200 with software Version 3.00 or higher, can be
controlled with a computer utilizing RS-232 and the Orban supplied 8200PC
software for Microsoft Windows, or through binary commands.
The Orban 8200PC software offers full access to all 8200 features, while the
binary communications method can only recall presets.
When set to On (default), this control allows remote control of the 8200
through RS-232 communications, only with the Orban supplied 8200PC
software for Microsoft Windows. Access to the 8200 is the same as under
Version 1.2x.
When set to Off, this mode disables all password protection entirely. PC
access using binary commands is allowed for recalling presets only.
Complete control by 8200PC is still allowed, however password protection is
OPTIMOD-FM 8200 V3.00 UPGRADE MANUAL ADDENDUM
disabled. Please note that in this mode, unauthorized access is possible, so
take measures to insure that a secure link is used to the 8200. Concurrent
8200PC and binary communications method is not possible.
The binary communications method is intended to be used primarily by
programmers for third-party software development. Orban Customer Service
will supply a developer's white paper upon request. We cannot, however,
provide any technical support for third-party software.
New Format Presets In Version 3.00
The 21 named format presets in Version 3.00 are entirely new. They exploit new Version
3.00 features, including the OUTPUT MIX controls for the 5-Band Limiter and the
HIGH FREQUENCY COUPLING control. They apply appropriate amounts of BASS,
PRESENCE, and BRILLIANCE equalization.
Of these 21 presets, five are duplicates because we felt that they were appropriate for
more than one format. So there are actually 16 distinct and different presets. Each preset
has full
presets from which they were taken and the nominal
LESS-MORE
Capability. The table below shows the presets, including the source
LESS-MORE
setting of each preset.
I-3
Many of the presets come in several “flavors,” like “dense,” “medium,” and “open.”
These refer to the density produced by the processing. “Open” uses SLOW multi-band
release time, “Medium” uses MEDIUM-SLOW release, and “Dense” uses MEDIUMFAST. FAST release is only used in the NEWS/TALK and SPORTS presets.
Important!
control to trade off loudness against processing artifacts and side effects.
Once you have used LESS-MORE, save your edited preset as a USER
PRESET.
Do not be afraid to experiment with presets other than the ones named for your format if
you think these other presets have a more appropriate sound. Also, if you want to finetune the frequency balance of the programming, feel free to enter FULL CONTROL and
make small changes to the BASS, PRESENCE, and BRILLIANCE controls. Remember
to do this after you have decided on a
have edited a preset using FULL CONTROL,
that edited preset. (Of course,
want to go back to it. There is no way you can erase or otherwise damage the factory
presets. So feel free to experiment.)
These presets are only suggestions. Try using the LESS-MORE
LESS-MORE
LESS-MORE
is still available for the unedited preset if you
setting that's right for you. Once you
LESS-MORE
is no longer available for
I-4
MANUAL ADDENDUM Orban
## PRESET NAME SOURCE PRESET NORMAL
LESS-MORE
____ __
FB GENERAL-MEDIUM ADLT CONTEMP-MED 5.0
FC GENERAL-OPEN ADLT CONTMP-OPEN 5.0
FD URBAN/RAP-DENSE URBAN/RAP-DENSE 7.0
FE URBAN/RAP-MEDIUM URBAN/RAP-MEDIUM 7.0
FF ROCK-DENSE ROCK-DENSE 7.0
FG ROCK-MEDIUM ROCK-MEDIUM 7.0
FH ROCK-OPEN ROCK-OPEN 7.0
FI ADLT CONTEMP-MED ADLT CONTEMP-MED 5.0
FJ ADLT CONTMP-OPEN ADLT CONTMP-OPEN 5.0
FK COUNTRY-MEDIUM ADLT CONTEMP-MED 5.0
FL COUNTRY-OPEN ADLT CONTMP-OPEN 5.0
FM POP-DENSE POP-DENSE 5.0
FN POP-MEDIUM POP-MEDIUM 5.0
FO POP-OPEN POP-OPEN 5.0
FP JAZZ JAZZ 5.0
FQ INSTRUMENTAL JAZZ 5.0
FR OLDIES-DENSE OLDIES-DENSE 7.0
FS OLDIES-OPEN OLDIES-OPEN 7.0
FT FOLK/TRADITIONAL POP-MEDIUM 5.0
FU NEWS/TALK N EWS/TALK 5.0
FV SPORTS SPORTS 5.0
OPTIMOD-FM 8200 V3.00 UPGRADE MANUAL ADDENDUM
I-5
ROCK:
(although not as exaggerated as the URBAN/RAP presets). There is enough presence
energy to ensure that vocals stand out. A modest amount of HIGH FREQUENCY
COUPLING allows reasonable amounts of automatic HF equalization (to correct dull
program material), while still preventing exaggerated frequency balances and excessive
HF density. These presets are appropriate for general rock and contemporary
programming. For Contemporary Hit Radio (CHR) we recommend the DENSE or
MEDIUM versions. For Album-Oriented Rock (AOR) use ROCK-MEDIUM or OPEN,
although you might prefer the more conservative Adult Contemporary presets here.
URBAN/RAP:
more bass. They use the 3-pole (18dB/octave) shape on the bass equalizer. They are
appropriate for Urban, Rap, Black, R&B, Dance and other similar formats.
ADLT CONTEMP:
and POP. They have a gentle bass and treble lift, along with enough presence energy to
help vocals to stand out. This preset is also used for COUNTRY, and is a useful
candidate for AOR formats.
POP:
substantial HIGH FREQUENCY COUPLING to ensure that the high frequencie s do not
become dense. This is an ideal preset for formats designed primarily for women listeners
(who, by and large, dislike hyped treble) or for any preset designed for long time-spentlistening formats because of its open, clean sound, which leads to very low listener
fatigue. Because of its conservative nature, this preset is also used for the
FOLK/TRADITIONAL preset.
The ROCK presets are designed for a bright high end and punchy low end
The URBAN/RAP presets are similar to the ROCK presets, but with
The Adult Contemporary presets are a compromise between ROCK
POP is a more conservative preset designed for a mellow, open high end. There is
OLDIES:
less. This allows the preset to do substantially more automatic equalization than ROCK,
making recordings of different eras more uniform. OLDIES-OPEN might be a useful
alternative to FOLK/TRADITIONAL if the recordings being played are very
inconsistent in frequency balance.
JAZZ:
play mostly instrumental music. It has a relatively mellow high end and produces very
low listening fatigue.
NEWS/TALK:
FAST 5 Band Release Time setting, so it can quickly perform automatic equalization of
substandard program material, including telephone. It is very useful for creating a
uniform, intelligible sound from widely varying source material, particularly source
material that is “hot from the field” with uncontrolled quality.
SPORTS:
GATE THRESHOLD is higher. This recognizes that most sports programming has very
low signal-to-noise ratio due to crowd noise and other on-field sounds, so the preset does
not pump this up as the NEWS/TALK preset would tend to do.
OLDIES is similar to ROCK except HIGH FREQUENCY COUPLING is
JAZZ is quite similar to POP, and is specifically tailored toward stations that
This preset is quite different from the others above. It is based on the
Similar to NEWS/TALK except the AGC RELEASE TIME is slower and the
I-6
MANUAL ADDENDUM Orban
New Multi-Band Features For Version 3.00
High Frequency Coupling Control (Band 3&4 Coupling)
High Frequency Coupling couples a certain percentage of the Band 3 gain control signal
into Bands 4 and 5. This forces Bands 4 and 5 to follow the gain reduction in Band 3 to a
user-adjustable extent. Because Band 3 has a slower release time than Bands 4 and 5,
this results in a more open high end. It also limits the amount of dynamic HF boost that
the processing can produce.
Even with the control at 100%, Bands 4 and 5 are still active and will produce further
gain reduction if this is necessary to prevent distortion. So in this mode they are acting as
a high frequency limiter.
Multi-Band Mix Controls (Band 1-5 Out Mix dB)
All of the equalization described so far occurs
advantage of this is that the multi-band limiter protects you against overloads or program
material with unusual spectral balance, which might otherwise combine with your
equalization curve to cause unpleasant distortion or coloration. In particular, it protects
the final clipper from being overdriven.
However, the
limiter tends to fight equalization settings that you made with the various equalizer
controls, reducing their effect. We have therefore provided a mix control with a ±3dB
range at the
These act as fixed equalizer controls because no gain reduction occurs after them. They
determine the overall target spectral balance of the processing when the multi-band
limiter exhibits substantial amounts of gain reduction. In popular music formats this is
almost always the case.
Please note that these controls are
limiter and multi-band clippers were tuned at great length to ensure that under virtually
no circumstances would program material come along to cause unpleasant clipping
distortion in the following clippers. By adjusting the multi-band mix controls, you upset
this carefully tuned relationship. Therefore, program material can come along that causes
unexpected (and sometimes very nasty-sounding) distortion because the final clippers are
being overdriven. This will occur if the program material in question has a significant
part of its energy concentrated in a frequency band that is being boosted.
downside
output
is that the “automatic equalization” effect of the multi-band
of each limiter in the five-band limiter.
very risky
. The thresholds of OPTIMOD-FM's 5-band
before
the multi-band limiter. The
In general, it is safe to turn a given output mix control
without danger of introducing distortion. However, you will lose loudness. If you turn an
output mix control up (+0.5 to +3dB range), you should listen at great length to a wide
variety of program material to make sure that nothing falls apart due to excessive
down
(in the 0 to –3dB range)
OPTIMOD-FM 8200 V3.00 UPGRADE MANUAL ADDENDUM
clipping distortion. If it does, you will need to back off the control in question and/or
back off the
If you turn up the control for Band 1 (below 100 Hz), you may wish to turn down the
Bass Clip Thrsh dB
between the bass multi-band clipper and the final clipper.
Final Clip
control.
control by an equal amount. This will preserve the relationship
Bass Clip Threshold Control (Bass Clip Thrsh dB)
The 8200 uses Orban's patented multi-band distortion-cancelling clipper system to
achieve a low peak-to-average ratio without creating audible distortion due to clipping.
The bass clipper is part of this system. It is embedded in the multi-band crossover so that
harmonics created by clipping are rolled off by part of the crossover filters. The
threshold of this clipper is ordinarily set between 4dB and 6dB below the threshold of
the final clipper in the processing chain, depending on the setting of the
control in the parent preset upon which you are basing your full control adjustments.
This provides headroom for contributions from the other four bands, so that bass
transients don't smash against the final clipper and “shut it down,” momentarily blocking
any other program material and causing a sound similar to very hard pumping. The bass
clipper also protects against overt intermodulation distortion between the bass and higher
frequency program material.
LESS-MORE
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Some 8200 users feel that the bass clipper unnecessarily reduces bass punch at its factory
settings. To accommodate these users, Version 3.00 software makes the threshold of the
bass clipper a user-adjustable control. The range (with reference to the final clip
threshold) is 0 to –6dB. As you raise the threshold of the clipper you will get more bass
but also more distortion and pumping. Be careful when setting this control; do not adjust
it casually. Listen to program material with heavy bass combined with spectrally sparse
midrange material (like a singer) and listen for IM distortion induced by the bass'
pushing the midrange into the final clippers. In general, unless you have a very good
reason to set the control elsewhere, we recommend leaving it at the factory settings,
which were determined as a result of exhaustive listening tests with many types of
critical program material.
Phase Rotator In/Out
The multi-band limiter receives the output of a three-pole phase rotation circuit. This has
a flat frequency response but a phase response that is nonlinear with frequency. Its
purpose is to make voice waveforms symmetrical, which minimizes clipping distortion
and makes voice (particularly live voice from microphone feeds) sound cleaner.
The downside of the phase rotator is that it subtly reduces the clarity and definition of
music. While this is unlikely to be heard on the vast majority of consumer radios, many
people listening with audiophile-quality gear will be able to perceive it. We therefore
have provided the ability to bypass this circuit, leaving only the phase rotation intrinsic
to the crossover topology in the multi-band limiter. This residual phase rotation is
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MANUAL ADDENDUM Orban
approximately 25% of the total phase rotation that occurs when the three-pole phase
rotator is active.
When you bypass the phase rotator, many voices sound audibly harsher because more
clipping occurs. This can be particularly problematical if you are processing heavily for
loudness. If you notice increased harshness on voice, we recommend that you use
external phase rotation (three cascaded poles, each tuned to 200Hz) in your live
microphone chain and in your production studio mic chain. If this is impractical, we
recommend leaving the 8200's built-in phase rotator active because we find the increased
voice distortion caused by leaving it off substantially more objectionable than the slight
loss of clarity that results when it is active.
Refer to the “Phase Rotator For Microphone Channel” diagram, on the following page.
OUTPUT
OPTIMOD-FM 8200 V3.00 UPGRADE MANUAL ADDENDUM
10K 1%
10K 1%
1K 5%
10K 1%
10K 1%
1/4 TL074
0.01uF 10%
82K 5%
1/4 TL074
0.01uF 10%
82K 5%
50V
50V
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10K 1%
10K 1%
1/4 TL074
1/4 TL074
INPUT
0.01uF 10%
82K 5%
82K 5%
50V
Figure 1: Phase Rotator for Microphone Channel
If you substitute a high-speed amplifier, layout and power supply bypassing become more critical.
Many audio opamps could be substituted for the TL074, like a pair of NE5532s.
Bypass (+) and (−) Power Leads of TL074 to Ground with 0.1µF 50V monolithic ceramic capacitors.
Operate from +15V and −15V DC power.
Notes: Unity Gain, Line Level.
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