Yamaha EM1620 - Manual (Page 8)

OPERATING TIPS
CONNECTING SOURCES SOUND LEVEL BALANCE AND CONTROL
INPUT
MIC -45dB
PIN 2: HOT (+) PIN 1: GROUND
PIN 3: COLD (-)
* MAKE SURE THE MIXER'S POWER SWITCH IS
OFF WHEN CONNECTING OR DISCONNECT­
ING ANY CABLES.
* ALWAYS TURN THE MIXER'S POWER ON AF^
TER TURNING ON CONNECTED SOURCES
SUCH AS ELECTRONIC INSTRUMENTS, ETC.
CONNECTING SPEAKERS
The EMI620 powered mixers have two 1/4" phone jack
speaker outputs which are internally connected in paral­
lel. This place some restrictions on their use.
* IF YOU CONNECT SPEAKER SYSTEMS TO
ONLY ONE OF THE AVAILABLE SPEAKER
OUTPUTS, THE TOTAL IMPEDANCE OF THE
CONNECTED SPEAKER SYSTEM MAY BE NO
LESS THAN 4 OHMS.
* IF YOU CONNECT SPEAKER SYSTEMS TO
BOTH OF THE AVAILABLE SPEAKER OUT­
PUTS, THE TOTAL IMPEDANCE OF THE
SPEAKER SYSTEM CONNECTED TO EACH
OUTPUT MAY BE NO LESS THAN 8 OHMS
(equalling a total of 4 ohms).
While a higher total load impedance than the recom­
mended impedance will only result in a loss of power
output, a total load impedance that is too low can actu­
ally damage the powered mixer. With a total load im­
pedance of 8 ohms, the maximum output power of
EM1620 mixers is 120 watts. With a total load imped­
ance of 4 ohms, maximum output power is 200 watts.
* NEVER CONNECT OR DISCONNECT SPEAK­
ERS WHILE THE MIXER'S POWER IS TURNED
ON!!
Before turning ON the mixer AC power switch, connect
all inputs, outputs, and speakers, and be sure the monitor
control is at “0”. If other electronic equipment or elec­
tronic instruments are connected to the inputs of the
EM1620, turn ON that equipment before turning on the
mixer. This will not only avoid annoying hum, it will
also prevent power-on transients from damaging speak­
ers or other equipment.
To obtain a good S/N ratio with little noise and wide
dynamic range, it is important to establish a proper bal­
ance between each channel VOLUME control and the
MASTER control. Generally speaking, to set the volume
of the signal at SP OUT and to obtain a good S/N ratio,
the channel VOLUME control should be set as higher as
possible and the MASTER control should be set low.
However, if the channel VOLUME is set too high, the
signal will clip, and the sound will become distorted.
Initially, set the channel VOLUME controls to “0”, and
the MASTER control to about “3”. Increase channel
volumes one at a time until the desired mix balance is
achieved; the VOLUME control of the channel with the
lowest signal level should be set somewhere between
“8” and “9”. At this point, if the overall volume is too
high or too low, readjust the MASTER volume accord­
ingly.
The same considerations apply to the MONITOR output.
Although the LIMITER circuitry is capable of handling
reasonable signal overranges without distortion, exces­
sively large power signals will be distorted. The best
policy for stable signal output is to keep the volume
turned down to avoid situations that activate the limiter
circuitry.