Rane MQ 15 Operating And Service Manual
OPERATING / SERVICE MANUAL
MQ 15/30
GRAPHIC EQUALIZERS
QUICK START
Reading this section is a lot like eating spinach. Once you’re through, you can have dessert. So read this spinach, then
devour your MQ dessert.
Hook-up is intuitive. Just follow the silkscreened instructions on the rear of the unit. All three inputs are wired in
parallel (they do not sum); and all three outputs are wired in parallel. Use any ONE input and any or all outputs. Using
the MQ 15/MQ 30 in an Insert Loop of a mixer is extremely easy. Simply connect them together using a single stereo
cable (1/4" TRS) between the mixer’s Insert Loop and the PATCH I/O jack. This jack is wired for the tip=send,
ring=return convention used by many mixer manufacturers. CAUTION: USE EITHER THE PATCH I/O OR ANY OF
THE INPUT AND OUTPUT CONNECTORS — DO NOT USE BOTH AT THE SAME TIME.
Anyone familiar with other graphic equalizers finds the MQ 15/MQ 30 just as familiar. One word of caution: the
boost/cut RANGE switch drastically changes the impact of a given filter. BE CAREFUL.
Setting the IN and OUT GAIN controls to the same physical positions gives unity gain through the equalizer. That is,
moving both slider handles together (keeping them aligned) always maintains overall unity gain from input to output.
Many strange gain structure conditions may be handled with these controls. FOR BEST NOISE PERFORMANCE
ALWAYS POSITION BOTH CONTROLS AS FAR TOWARD THE TOP OF. THE UNIT AS POSSIBLE WITHOUT
LIGHTING THE OL INDICATORS. See the Operating Instructions on the back page for more information, Most
applications require only a few dB of boost or cut. Start with the RANGE switch in the 6dB position and increase to
12dB only if necessary. Setting curves is as easy as it is on all Rane graphics thanks to our unique interpolating constant-
Q circuitry. For more information on setting up your curves correctly, again, see the back page.
NEVER CONNECT ANYTHING EXCEPT AN APPROVED RANE POWER SUPPLY TO THE RED THING
THAT LOOKS LIKE A TELEPHONE JACK ON THE REAR OF THE UNIT. This is an AC input and requires
special attention if you do not have a power supply EXACTLY like the one originally packed with your unit. See the full
explanation of the power supply requirements elsewhere in this manual.
SYSTEM CONNECTION
When first connecting the MQ 15 to other components, LEAVE THE POWER SUPPLY FOR LAST. This gives you a
chance to make mistakes and correct them without damaging your fragile speakers, ears and nerves.
INPUTS. All three inputs are wired in parallel and are actively balanced (true instrumentation amplifiers). Each works
equally well. Choose strictly from a favorite hardware point-of-view, there will be no performance trade-offs. The wiring
convention adheres to American, British and International standards of pin 2 “+”, or tip being hot, pin 3 “–”, or ring being return,
and pin 1, COMMON GND, or sleeve being signal ground. Unbalanced operation involves using only pin 2 “+”, or tip as
signal and pin 1 COMMON GND, or sleeve as ground. It is not necessary to short any terminals or pins to any others. Due
to the true instrumentation nature of the inputs, there is no gain reduction if pin 3, or –, is left open; however, if pin 3 gets
shorted, it won’t hurt anything either. Use pin 1, the shell, or the COMMON GND point on the barrier strip for shield
ground. (See Rane Note 110 for further information).
OUTPUTS. The outputs mimic the inputs. True balanced output interconnection only requires the use of pin 2 “+”, or tip,
and pin 3 “–”, or ring for signal transmission. It does not require pin 1, or signal ground. The signal exists differentially
between the two balanced leads; ground is not involved. Ground is used only for shielding. Again, have a look at Rane Note
110 for more detail.
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