Rane GE 30 Operator's Manual

OPERATORS MANUAL
GE 30
GRAPHIC EQUALIZER
QUICK START
If you are one of those people who think owner’s manuals are included with a product to help absorb shock and vibration during
shipment, you are a lot like we are. This section is for you. You want to fire up your equalizer without wading through a bunch of
stuff in manuals. Great. Read on. We’ll keep it short.
Set the input LEVEL control to about 6. This is approximately unity gain in the BOOST/CUT mode. (In the CUT-ONLY
mode the level control should be set to 2 for unity gain.) Your sound system should be set up such that gain or loss is not required in
the equalizer(s). Set the EQ MODE switch on the rear for the desired operating mode, CUT-ONLY or BOOST/CUT. The LEDs on
the front illuminate, telling you which mode you are in. Set the OUTPUT MODE switch on the rear for the desired output coupling
mode (ACTIVE or TRANSFORMER COUPLED). Adjust the LOW CUT and HIGH CUT FILTER controls on the front for
the desired low and high cut frequencies. Full counterclockwise on the LOW CUT control and full clockwise on the HIGH CUT
control essentially defeats these functions.
If you read only this section, we assume you know how to set up an equalizer. So set the sliders where you want them and you’re
outta here.
Never connect anything except an RS 1 or other approved Rane AC power supply to the thing that looks like a telephone
jack on the rear of the GE 30. This is an AC input and requires some special attention if you do not have an operational power
supply EXACTLY like the one that was originally packed with your unit. See the full explanation of the power supply requirements
elsewhere in this manual.
GE 30 CONNECTION
When connecting the GE 30 to other components in your
system for the first time, leave the power supply for last. This will
give you a chance to make mistakes and correct them before any
damage is done.
INPUTS on the GE 30 are balanced. They may be connected for either balanced or unbalanced operation. This product
offers the choice between going in and out of it using either the
3-pin connectors or the handsome black #6 terminal strips with
the finely plated screws. We will describe here the use of the 3pin connectors. The terminal strips are connected in parallel and
are used in the same way. Only the names have been changed.
Pin 2 is hot “+”, pin 3 is return “–”, and pin 1 is chassis ground.
Balanced inputs require the use of pins 2 and 3. Pin 1 is unnecessary unless you are using it for shield ground. For unbalanced
operation, pins 1 and 3 must be shorted together to prevent 6 dB
of gain reduction. Drive pin 2 as hot and the combination of 1
and 3 as ground.
WEAR PARTS: This product contains no wear parts.
OUTPUTS are balanced as well and follow the same convention as the inputs. There are some tricky things to be careful
of at the output. If active balanced operation is your preference,
hot “+” and return “–” should be all that is required. It does
not take three wires to conduct a signal from one unit to the
next. Connect the shield to case or chassis ground. Transformer
balanced outputs are connected in the same manner. Active unbalanced output requires “+” and ground only. Use pins 2 and 1
respectively. In this mode, do not short pins 1 and 3. If, however,
you are using the transformer coupled mode and are running
unbalanced, do short pins 1 and 3 or you will get little or no
output. In case you haven’t noticed, if you plan on throwing the
selector switch very often it’s a good idea to connect everything
in a balanced configuration.
Manual-
FRONT PANEL DESCRIPTION
1 POWER switch. Pressing the top half of this switch causes the mechanism contained within to connect power from the remote
power supply to the circuitry of the unit causing it to operate (ON). Pressing the bottom half snaps the switch to the opposite
operating mode (OFF).
2 SIGnal present indicator illuminates green when an input signal greater than -20 dBm is applied to the unit, regardless of the
position of any controls on the unit, including the BYPASS switch.
3 OverLoad indicator glows or flashes red when the signal passing through the unit is within 4dB of the maximum allowable level
at some point in the circuitry.
4 LEVEL sets the Level of the signal coming into the GE 30. Turn this control down if the OVERLOAD LED lights up steadily
(meaning too strong an Input signal). Since actual unity gain depends on varying slider settings (which is why we have not
marked a unity gain position on the front panel), use the BYPASS switch to determine the exact unity gain position of this
LEVEL control by comparing EQ and BYPASS loudness. Full counterclockwise rotation of this control provides full input attenuation (signal off), full clockwise rotation yields a minimum of +6 dB of gain in the BOOST/CUT mode, or a minimum of +20 dB
of gain in the CUT-ONLY mode.
5 Overall BYPASS switch and indicator. Pressing this button to its in and locked position provides a complete “hard-wire” bypass
of all active circuitry in the GE 30, including grounds. The GE 30 automatically switches to the Bypass mode in the event of a
power failure. This insures that should something fail in the power supply of the unit, signal passes to the rest of the system. The
indicator illuminates red when the GE 30 is placed in the Bypass mode via the switch.
6 Equalization controls. These 60 mm slide controls set the relative level of boost or cut at each 1/3-octave frequency location. The
effect of each control is indicated by one of two calibration scales, the selection of which is denoted by an illuminated yellow LED
located at the top of the CUT-ONLY scale and at the center of the BOOST/CUT scale.
7 LOW CUT filter control rotates in a clockwise direction to increase the frequency of the low filter cutoff. The calibrations on the
front panel indicate the -3 dB point of the filter. Rotating this control to its full counterclockwise position effectively bypasses the
filter.
8 HIGH CUT filter control rotates clockwise to increases the frequency of the high cut filter cutoff. Like the low-cut filter, the
calibrations reflect the -3 dB point of the filter. Full clockwise rotation effectively bypasses the filter.
9 CUT-ONLY indicator illuminates yellow when the EQ MODE select switch on the rear panel is depressed, placing the GE 30 in
its CUT-ONLY mode.
0 BOOST/CUT indicator illuminates yellow, advising the operator that the rear mounted EQ MODE function select switch is in
its OUT position, placing the GE 30 in the + 12 BOOST/ -15 CUT mode.
Manual-
REAR PANEL DESCRIPTION
1 XLR INPUT connector. This is a fully differentially balanced Input, connected such that pin 2 is hot “+”, pin 3 is return “–” and
pin 1 is chassis ground. For unbalanced operation, drive pin 2 as hot, and pin 3 as return. For grounding and shielding information, consult the RaneNote 110, “Sound System Interconnection” section for expanded details.
2 XLR OUTPUT connector. Again, a fully differentially balanced socket, pin 2 is hot “+”, pin 3 is return “–” and pin 1 is chassis
ground. Balanced output configuration should use only pins 2 and 3. Ground is not required in this mode. Use the case for shield.
If unbalanced operation is your cup of mud, use pin 2 as hot and pin 1 as return or ground unless your are running unbalanced output in the TRANSFORMER coupled mode, then you must short pins 1 & 3 together. This is not recommended, however, for the active
unbalanced mode. Again, see the “Sound System Interconnection” section for further clarification.
3 Screw terminal INPUT and OUTPUT connector. These #6 terminals directly parallel the pins in the XLR Input and Output
connectors. Their use or disuse is completely up to the judgement of the installer.
4 OUTPUT MODE switch. Pressing this switch in to its locked position places the output stage into its TRANSFORMER
COUPLED balanced mode, and illuminates the yellow LED. Pressing the switch again to release it from its in position causes the
GE 30 to be placed back into its ACTIVE balanced output mode, extinguishing the yellow LED and lighting the green LED.
5 EQ MODE switch. Pressing this switch to its in and locked position selects the CUT-ONLY mode, a fact attested to by the
CUT-ONLY LED indicator on the front panel. Pressing the switch again to release it to its out position places the unit back into
the BOOST/CUT mode, which reconfigures the LEDs on the front panel.
6 Remote power supply input. Use only an RS 1 or other remote AC power supply approved by Rane. The GE 30 is supplied from the
factory with a remote power supply suitable for connection to this input jack. It is not a telephone jack. The power requirements of
the GE 30 calls for an 18-24 volt AC center-tapped transformer only.
7 Chassis ground point. A #6-32 screw is used for chassis grounding purposes. See the note below.
CHASSIS GROUNDING
If after hooking up your system it exhibits excessive hum or buzzing, there is an incompatibility in the grounding configuration
between units somewhere. Your mission, should you accept it, is to discover how your particular system wants to be grounded. Here
are some things to try:
1. Try combinations of lifting grounds on units that are supplied with ground lift switches or links.
2. If your equipment is in a rack, verify that all chassis are tied to a good earth ground, either through the line cord grounding pin or
the rack screws to another grounded chassis.
3. This unit’s outboard power supply does not ground the chassis through the line cord. Make sure that this unit is grounded either to
another chassis which is earth grounded, or directly to the grounding screw on an AC outlet cover by means of a wire connected to
a screw on the chassis with a star washer to guarantee proper contact (see #7 above).
Please refer to the RaneNote, “Sound System Interconnection” included with this manual for further information on system
grounding.
Manual-
OPERATING INSTRUCTIONS
HYPERBOLE
The GE 30 is, as are all Rane equalizers, a constant bandwidth device. This guarantees that the Q (a measure of bandwidth) of all the 1/3-octave filters will be maintained regardless
of the position of the filter’s slide control. This is accomplished
by completely isolating the center frequency and bandwidth
parameters of each filter from the variable resistor connecting the
filter to the signal path. The sliders simply act like mixer faders
would; they sum the outputs of the filters to one of four different
buses—two boost buses and two cut buses. This sort of careful attention to design allows Rane equalizers to perform as no
others.
A further benefit of the constant-Q approach is the ease with
which 0dB of boost or cut can be guaranteed when the control is
set at zero. The filter slide controls feature a grounded center tap
in the Boost/Cut mode and a grounded 0dB position in the CutOnly mode. This ensures that none of the filters will affect the
response of the unit when their contribution is unwanted.
The automatic Bypass function of the GE 30 guarantees that
if power is lost, signal will not be. The Bypass relay automatically
closes the bypass loop when either the POWER switch is turned
off, the line cord is disconnected, or some other power interruption occurs.
The Rane Model GE 30 is a professional equalization tool,
and as such, it would not be wise for us to recommend that you
“Fiddle with it ‘til it sounds good.” It is because of this that we
offer the following:
MEASUREMENTS
We highly recommend that a real time analyzer be used to
display the combined sound system/room response so intelligent
adjustments may easily be made without a lot of trial and error.
Of course, Rane Corporation builds a very nice one (the RA 30),
at a very reasonable price if you are not already in possession of
one.
DICE OR SLICE?
Deciding whether the GE 30 should be operated in the
Boost/Cut mode or the Cut-Only mode is a bit of a sticky
problem. For that matter, referring to the Boost/Cut mode versus
the Cut-Only mode is bound to cause some debate among more
than a few readers. There are those that believe it makes no difference which mode you use, and there are just as many others
who believe that one or the other is the one and true way to go.
This is exactly why the GE 30 offers the options it does. There
are situations where a person of the Cut-Only persuasion needs
to use the “other” type EQ in certain selected locations. If this is
the case, all this person needs to do is get around behind the rack
(hopefully this isn’t too difficult) and press the EQ MODE selector. There are others who are not as convinced that one or the
other modes is better, but wish to withhold the decision until the
job is installed and ready for test. Whichever the case, the GE 30
performs its duty better than any other product of either type.
AMPUTATION
Setting the corner frequencies of the High Cut and Low Cut
filters is a function of the type of system and the type of material
that passes through the system. For most installations, a setting of 40Hz on the low end and 15 to 20kHz on the high side
will be adequate for protecting expensive drivers and associated
equipment. Should the user prefer these filters have no effect
at all, rotating them to their respective high and low frequency
extremes effectively removes them from the signal path. In all
cases, a somewhat careful study should be made of the overall
system requirements so that the individual 1/3-octave controls
are not used to correct for an improper setting of these filters.
ISOLATION
Finally, select the output configuration (Active or Transformer) which suits your requirements. In most situations, the
ACTIVE option is probably the best, since it offers the highest
linearity and bandwidth. The degradation caused by the transformer is very slight, and will not contribute anything audible
to the system if this mode is selected. The differences are more
theoretical than practical.
ENLIGHTENMENT
See the RaneNote “Constant-Q Graphic Equalizers” for an
awareness of the benefits of the GE 30’s constant-Q interpolating
filters, available from Rane's website.
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 TEL 425-355-6000 FAX 425-347-7757 WEB www.rane.com
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