YORKVILLE MM6 Manuel De L'utilisateur page 5

graphic EQs that are designed to be rack mounted operate on line level signals. Foot pedal
effects typically operate with lower signal levels, but may still be used if you are careful to
reduce the RVB/EFX levels and to increase the MAIN EFFECTS accordingly.
These jacks have some other uses. The EFX SEND jack may be used as a separate sub-mix
output. In this case turn down the MAIN EFX controls. The mix at this jack is determined by
the settings of the individual RVB/EFX controls on the channels. The EFX RTN jack can serve
as an auxiliary (Bus) input to the main mix. In this case the signal delivered to the EFX RTN
jack can be adjustably sent to the main mix via the MAIN EFX control. The entry point from
the EFX RTN jack to the main mix is before the MM6's graphic equalizer.
Built in 6 Band Graphic Equalizer
The graphic equalizer is used to adjust the system frequency response. There are 3 main rea-
sons this is useful.
The first is to adjust the system for feedback reduction. The normal technique is to turn the
system up to the verge of feedback and move the eq sliders one at a time to determine which
frequency band is causing the feedback. The offending band is then pushed down about 3 to 6
dB and the process repeated. Usually only 2 or 3 bands can be reduced before the feedback
elimination process begins to affect the sound quality.
The second use for the graphic equalizer is to adjust for deficiencies in the speaker response.
The most common is to boost the 63 Hz about 6 dB and the 100 Hz about 3 dB. In applica-
tions where it is appropriate to sacrifice deep bass for overall output the 63 Hz should be
taken down 6 dB. Use of the graphic eq to extend the frequency response of a speaker cabinet
does use up a lot of the available power so this technique should be used with caution.
The third use of the graphic equalizer is to adjust the sound character for artistic reasons.
Each band is adjusted until the sound is what the musicians feel sounds best. The best sound
system operators however usually strive to use a minimum of equalization.
POWER ON LED
This just lets you know that the MM6 is plugged in and turned on. The AC power switch is on
the rear panel of the unit.
R R E E A A R R P P A A N N E E L L
The back panel of the MM6 is very simple. Two standard 1/4 inch phone jacks are intended
for speaker connection. You may connect an 8-ohm speaker cabinet to each jack. If you wish
to use a 4-ohm cabinet, remember that you can connect only one such cabinet without
severely limiting the output power.
Aside from the amplifier outputs, the rear panel has only the AC power switch and the fuse.
Do not obstruct the flow of air around the heatsinks on the rear of the MM6, as this may
cause the unit to overheat. There is an internal shut down circuit that will reduce the level, or
shut down the power amp completely, if the unit gets too hot. Just wait a while; the MM6 will
cool down and sound will be restored automatically. This should never happen if adequate
ventilation is provided to the back of the unit.
P P O O W W E E R R A A M M P P
The power amplifier in the MM6 is designed to provide fault tolerant operation under almost
any condition. Accidentally shorting the amplifier outputs will cause the power amplifier to
shut down until the fault condition clears. Attempting to connect too many cabinets to the
MM6 outputs, (load impedance less than 4-ohms), may cause a loss in output power. This will
not damage the MM6 although it may run hotter.
MICROMIX
MICROMIX
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