Electro-Voice BK-1632 - Bk-1632 Stereo Mixer; Input Channel Controls; Trim

BK-1632 STEREO MIXER
Input Channel Controls
SECTION 1.0
1.0 INPUT CHANNEL CONTROLS (Figure 1)
The input channel is the beginning of the signal process¬
ing phase of the mixer. Each input channel will accept
one signal source which may be then equalized, have
reverb or other effects added, sent to a monitor system,
and last but not least, sent to the main system for the
audience to hear. Each input has a low impedance
microphone input (the 3-pin XLR or Cannon connector)
and a high impedance mic or line input (Vi in. phone
jack). The line input will accept signals from an instru¬
ment, high-impedance microphone, tape machine, elec¬
tronic drummer or almost any other audio source. Always
make sure that the channel fader (sec. 1H) or master
faders (sec. 2H) are down before plugging or unplugg¬
ing input sources.
1 A. TRIM
The TRIM control adjusts the gain or amplification
of the input amplifier. This is necessary to accom¬
modate the wide varation in signal strength
presented to the mixer by the almost endless variety
of signal sources — vocal mics. instrument mics,
tape machines, etc. The TRIM control allows you
to optimize the amplification for each individual
input source. This results in the best signal-to-noise
ratio (... no hiss) and at the same time, best
freedom from overload distortion.
The TRIM control is used to match the gain of the
first preamp stage to the signal strength of the
source being run through the channel. To get the
cleanest, quietist operation from the board it is
important that the TRIM control be properly set.
To set up a mix, first set all TRIM controls at "O"
(minimum). Set all the input and subgroup slide
faders at "0”. Then adjust the TRIM controls for a
rough mix (see sec. 11), and do the fine tuning with
EQ and faders as necessary. Whenever possible,
it is best to try to maintain that "straight line” rela¬
tionship between all faders. When this is done, all
the levels within the console are very close to being
optimized for the best noise and distortion perfor¬
mance. Once the correct TRIM setting is establish¬
ed, make all volume adjustments with the
appropriate channel fader (sec. 1H).
In general, the lowest noise operation (greatest
dynamic range) will be obtained when the TRIM
control is set at a point just below where the CLIP
light would flash.
FIGURE 1 — Input Channel Functions
1J — CHANNEL PATCHING
INSERT JACK
> 1A — TRIM
- 1B1 — HIGH EQUALIZER
> 1B2 — MID EQUALIZER
■ 1B3 — LOW EQUALIZER
■ 1C — EFFECTS REVERB
SEND
■ ID — MONITOR SEND
IE — AUXILIARY SEND
PRE/POST SELECT
• IF — PAN POT
■ 1G — PFL SWITCH & LED
II — CLIP LED
■ 1H — CHANNEL FADER
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