Electro-Voice BK-1632 User manual

Eiedrol/bice
BK-1632
STEREO MIXERS
OWNER’S MANUAL
BK-1632
STEREO MIXER

INTRODUCTION
Congratulations — you have just made one of the ‘‘best
buys” of your audio career. The Electro-Voice BK-1632
was designed to deliver exceptional performance at an
affordable price.
The BK-1632 provides the flexibility and sonic quality
required by today’s working musician. The five mixing
busses and channel patch points enable the use of
multiple effects and processors. The prefade listen or
solo system is invaluable for fine-tuning the mix. Vocalist
will find the reverb to monitor send useful in providing a
"wet mix” for stage monitors. With the addition of
on-board phantom power, any dynamic or condenser
microphone can be used without separate power
supplies.
The BK-1632 is a welcome addition to the growing
family of Electro-Voice electronic products. The
engineers at Electro-Voice have put 30 years of audio
know-how and pride into the BK-1632.

Table of Contents
BK-1632 STEREO MIXER
TABLE OF CONTENTS
I INTRODUCTION
1. INPUT CHANNEL CONTROLS
AND FUNCTIONS
1A Trim
1B EQ Controls
1C Effects Reverb Send
1D Monitor Send
1E Auxiliary Send
IF PAN Pot
1G PFL
1H Channel Fader
II Channel Clip LED
1J Channel Patching Insert Jack
2. OUTPUT SECTION CONTROLS
AND FUNCTIONS
2A Effects Master Send
2B Effects Return Level
2C Effects PAN
2D Auxiliary Master Send
2E Auxiliary Return Level
2F Auxiliary PAN
2G Reverb Section
2G-1 Reverb Level
2G-2 Reverb PAN
2G-3 Reverb to Monitor
2H Master Section Controls
2H-1 Left Submaster
2H-2 Right Submaster
2H-3 Main Master
2H-4 Monitor Master
2J Meter Assignment Switch
2K LED VU Indicators
2L Subgroup Insert Jack
2M Lamp Connector
2N Power Indicator
20 Phantom Power Switch
2P Phantom Power Indicator
2Q Phone Gain
2R Headphone Jack
3. REAR PANEL INPUT CONNECTORS
3A Balanced Low-Z Mic Input
3B High-Z Line Input
3C Effects Return
3D AUX Return
3E Effects IN
3F Monitor IN
3G Aux IN
4. REAR PANEL OUTPUT CONNECTORS
4A Sub R — Right Subgroup Output
4B Sub L — Left Subgroup Output
4C Main Output
4D Monitor Output
4E Effects Send
4F AUX Send
5. TROUBLESHOOTING
WARRANTY
6. SCHEMATIC DIAGRAMS
SPECIFICATIONS
SIGNAL FLOW DIAGRAM
one

BK-1632 STEREO MIXER
Specifications
GENERAL SPECIFICATIONS
FREQUENCY RESPONSE -
Mic Input to Any Output. EQ Flat. All Faders Nominal
20-20.000 Hz ± 1 dB
TOTAL HARMONIC DISTORTION -
<0.05% at *f4 dBu 1 . 20-20,000 Hz
<0 10% at +20 dBu, 20-20,000 Hz
NOISE -
(20-20,000 Hz with 150-ohm input Impedance)
-128 dBu EIN-equivalent input noise, mic input
(theoretical minimum nocse is -130 dBu across 150 ohms)
-90 dBu residual at mam out (an faders down)
-90 dBu residual at monitor out
INPUT CHANNEL EQUALIZATION —
± 15 dB shelving at 100 Hz
± 12 dB peak/dip at 3 kHz
± 15 dB shelving at 10 kHz
MICROPHONE INPUTS —
Low mpedance, balanced — pm 2 reference positive
Maximum input level +6 dBu (1.5 V)
Input impedance at 1 kHz; 4 4 kQ
Common Mode Refection Rato.
Typical: -65 dB
Minimum, 60-10.000 Hz: -50 dB
LINE INPUTS —
High impedance, balanced op positive
Maximum input level: +24 dBu (12 V)
Input impedance. 70 kQ
PEAK INDICATOR THRESHOLD
+ 15 dBu
MAXIMUM VOLTAGE GAIN ±3 dB —
85 dB — Mic In to Main Out 60 dB — Line In to Mam Out
75 dB — Mic In to Monitor Out 50 dB — Line In to Monitor Out
75 db — Mic In to Sub Out 50 dB — Line In to Sub Out
52 dB — Mic In to Insert Jack 27 dB — Line In to Insert Jack
82 dB - Mic In to EFX Send 57 dB - Lme In to EFX Send
50 dB — Lme m to AUX OUT
Left Inse rt _
Right Insert
EFX Return _
EFX Input_
Monitor Input
Aux Return
Input-Channel Insert 1
LINE LEVEL INPUTS
MAXIMUM
LEVEL
+ 20 dBu *
+ 20 dBu
+ 40 dBu
+ 29 dBu
+ 20 dBu
+ 5 dBu
Aux Input +29dBU
1. Requires a source impedance of 100 Q or less
INPUT
IMPEDANCE
100 kQ
100 kQ
>15 kQ
16 kO
10 kQ
>15 kQ
1 8 k Flat EQ.
1 k Max
Boost EQ
10 kQ
CROSSTALK —
-75 dB typical — Adjacent inputs. 1 kHz
- 75 dB typical — Input to output. 1 kHz
- 50 dB minimum — All combinations. 20-20.000 Hz
LAMP CONNECTOR -
BNC connector. 12 6 V ac/0 20 amps maximum
PHANTOM POWER —
48 V dc at pins 2 and 3 on mic connector. 3.4 kQ source resistance
LEVEL DISPLAY -
10-Segment LED In 3 dB Steps:
Range: - 18 dB to +9 dB
Reference “O' +4 dBu
Response Full wave, average responding
HEADPHONE OUTPUT —
Output: 20 mW into 8 O
Frequency Response: 50-15 kHz ±2 dB
PFL (pre fader listen): Switchable for input and
output
channels
AUX SEND Input Channels: Switchable pre- or
post-fader and EQ
DIMENSIONS -
Height: 130 mm (5 125 m.)
Depth: 460 mm (18 125 in.)
Width: 632 mm (32 75 in.)
NET WEIGHT —
16 8 kg (37.0 lb)
POWER REQUIREMENT —
25 Watts Maximum
Available kx 95-130 volts. 60 Hz
OUTPUTS
MAXIMUM 1
MINIMUM
INTERNAL
LEVEL
LOAD IMPEDANCE
Main
+ 20 dBu 600 Q
50 Q
Monitor
+ 20 dBu 600 Q 50 Q
Left Sub
+ 20 dBu 600 Q
50 Q
Right Sub + 20 dBu 600 Q
50 Q
Left Insert
+ 20 dBu
600 Q
50 Q
Right Insert
+ 20 dBu
600 0
50 Q
EFX Send
+ 20 dBu
600 Q
50 Q
Input-Channel Insert
+ 20 dBu
2000 Q 100 Q
Aux Out
+ 20 dBu
600 Q 50 Q
1 0 dBu is 0 775 volts. RMS
two

Signal Flow Diagram
SIGNAL FLOW DIAGRAM
three

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
four

EQ Controls
BK-1632 STEREO MIXER
IB. EQ CONTROLS
Equalization can be more simply described as
sophisticated tone control. The EQ circuits used in
the BK-1632 have a substantial amount of boost
and cut capability.
This wide range can be a bonus when dealing with
instrument signals, poor acoustics or other
problems. Use them sparingly, however, for the
best results.
1. HIGH EQ 10 kHz SHELVING TYPE
±15 dB
Controls the treble content of the input signal.
Turning the control counterclockwise decreases
the amount of treble, clockwise increases it.
2. MID EQ 3 kHz PEAK/DIP
±12 dB
Controls the midrange content of the input
signal. Turning the control counterclockwise
decreases the amount of midrange,
clockwise increases it.
3. L O W EQ 100 Hz SHELVING TYPE
±15 dB
Controls the bass content of the input signal.
Turning the control counterclockwise decreases
the amount of bass, clockwise increases it.
1C. EFFECTS/REVERB SEND
The EFFECTS/REVERB send control determines
how much of that input signal is sent to the internal
spring reverb and/or external effects. It is affected
by the channel EQ controls (sec. IB) and the
channel fader (sec. 1 H).
Turning the control clockwise increases the amount
of reverb and/or effects applied to that input signal;
counterclockwise decreases the amount.
Since each channel has its own EFFECTS/REVERB
send, some channels can have reverb or effects
and others none. Note that since the internal reverb
and external effects share a common send, they
will always have the same sources. That is, it is not
possible to have only reverb on one input source
and only effects on another input source at the
same time (unless the insert point is used). It is
possible to have reverb and effects simultaneous¬
ly on both input channels, however.
The EFX/REVERB send may also be used as mono
send. This might be useful for a tape recorder send,
for instance.
I.D. MONITOR SEND
The monitor send control sets the level of that input
signal in the monitor mix. It is independent of all
input channel controls except TRIM control (sec.
1A). It is not affected by the channel EQ controls
or slide fader. Thus, it is independent of, and not
affected by, changes in the main or house mix.
IE. A UX I L I A R Y SEND
The auxiliary send control sets the level of that input
signal in the auxiliary mix and is switchable PRE-
POST-EQ and fader. In the PRE position it serves
as another "MONITOR OUT" and in the POST
position, another "EFFECTS OUT."
The auxiliary send may also be used as a send for
recording.
IF. PAN POT
Short for "panoramic potentiometer.” This control
allows you to place the channel's input signal within
the stereo image by assiging more or less of the
signal to the left or right submaster controls.
Turning the panpot to the left of center moves the
apparent source toward the left channel, turning it
to the right moves the source toward the right chan¬
nel. Centering the control makes the apparent
source centered between the channels. If all inputs
are panned center, the result is mono. Proper use
of the PAN control cna sometimes help to control
acoustic feedback in a sound reinforcement system
by "panning" a mic away to the loudspeaker on
the opposite side of the stage.
IG. PFL
PFL (Pre-Fader Listen) allows the operator to
monitor any pre-fader signal individually or in com¬
binations, through the headphone output.
To activate the PFL simply depress the appropriate
switches. The status indicator will light indicating the
pre-fader signals being monitored.
In the normal position (all PFL switches off) the
headphone circuit monitors the output of the "Left"
and "Right" Submaster outputs.
The audio level at the HEADPHONE |ack (2 R) is
controlled by the PHONE GAIN control (2 Q)
IH. CHANNEL FADER
The side fader controls the output level of the chan¬
nel as it is fed to the subgroups. The control should
be normally set at the "0" mark. With all controls
five

Clip LED
BK-1632 STEREO MIXER
set to their designated normal operating points, the
circuits in the board are optimized for minimum
noise and distortion. In other words, the signal
levels are high enough to keep noise from creep¬
ing in and low enough to ensure plenty of
headroom and freedom from clipping distortion. If
the fader must run wide opten to get enough level,
turn up the TRIM control or increase the setting'of
the left and right submaster controls. Conversely,
if the fader must be pulled way back to get the right
level, the TRIM control or stereo submasters should
be adjusted. Adjust the TRIM control if the CLIP
LED lights, otherwise adjust the stereo submasters.
For optimum performance, the channel FADERS
(sec. 1H) should be run close to the "0” mark.
II. CLIP LED
The channel CLIP LED monitors the input channel
circuit for clipping or overload (both before and
after the EQ section). If it lights, you are bordering
on distortion. You’ll hear this in the output as a
harsh, blaring sound on volume peaks This might
be caused by excessive boost in the channel
equalization controls (sec. IB), or a TRIM control
setting that is too high for the input signal (sec. 1 A).
Generally, readjusting the TRIM control (sec. 1A)
will suffice.
1J. CHANNEL PATCHING INSERT JACK
(one supplied with the unit)
This space saving (two-connectors-in-one) jack
allows you to add external signal processing gear
to a particular channel, without disturbing any of
the other channels. A 3-conductor (stereo) phone
plug is used for both the output from the channel
preamp, and for the return to the mixer’s output
stages from the external processing device. The
diagram indicates how a channel patching cord
should be wired. This cable can also be purchas¬
ed from any of several audio cable manufacturers.
HOW TO WIRE A CHANNEL PATCHING CORD
The channel patching jack can be used with
equalizers, limiters, compressors, external reverb
or dealy systems and the like. Just be sure the
device you want to patch in has line level unbalanc¬
ed inputs and outputs. The signal at the insert jack
can drive loads of 2,000 ohms or greater, and the
external processing device should have a low out¬
put internal impedance (100 ohms or less).
A nominal input signal is a level of +4 dBu; the
maximum level is +20 dBu.
FIGURE 2 — Output Section Controls
and Functions
six

Output Section Controls
BK-1632 STEREO MIXER
SECTION 2.0
2.0 OUTPUT SECTION CONTROLS (Figure 2)
2.A EFX SEND
The EFX (effects) SEND control sets the level of the
signal appearing at the effects send output jack
(sec. 4E) going to any type of outboard effects
device(s) such as delay, phase, flanger, etc. It does
not affect the signal being sent to the internal reverb
system. The source for this signal is via the
individual effects/reverb send level controls
(sec. 1C) on input channels 1 through 16.
2B. EFX RETURN
The EFX RETURN level control determines the
amount of externally generated effects signals in
the main mix. This signal is mixed into the left and
right stereo sub channels via the EFX PAN control
(sec. 2C).
2C. EFX PAN
The EFX PAN control directs the signal coming
from the effects return level control into the left
and/or right sub channels. The control works in an
identical way to the input channel PAN control.
2D. AUX SEND
The AUX (auxiliary) SEND control sets the level of
the signal appearing at the AUX SEN D output jack
(sec. 4F) to any outboard device. The PRE-POST
select switch on the channel input will allow you to
determine if you want the outboard device to be
affected by the channel equalization and fader. In
the "PRE" position, the AUX SEND signal is not
affected by the channel EQ and fader. In the
"POST" position, the AUX SEND signal is affected
by the channel EQ and fader.
2E. AUX RETURN
The AUX (auxiliary) RETURN control sets the level
of the input signal that is directed to the left and
right sub channels through the AUX PAN control
(sec. 2F) The AUX RETURN is one of the input
locations that can be used to "stack" mixers without
using up an input channel.
2F. AUX PAN
The AUX (auxiliary) PAN control directs the signal
coming from the AUX input into the left and or right
sub channels. The control works in an identical
manner to the input channel PAN control.
2G. REVERB SECTION
Reverberation is the natural decay of sound in a
closed space (a room). The internal reverb system
uses springs to realistically simulate this effect.
The reverb section gets its input signal from the
EFX/REVERB send controls on the input channels
(sec. 1C).
1. REV LEVEL
The REV (reverb) LEVEL control adds rever¬
beration to the left and right sub channels from
any input channel signal whose EFX/REV
control is turned up.
Turning the control to the right increases the
amount of reverb present in the left and right
sub outputs.
2. REV PAN
The REV (reverb) PAN control directs signal
from the REV LEVEL control to left or right sub
bus. The control works in an identical manner
to the input PAN control.
3. REV TO MON
The REV (reverb) to MON (monitor) control
adjusts the level of the signal from the internal
reverb to the monitor bus. Turn the control
clockwise to increase the reverb level at the
monitor bus.
2H. MASTER SECTION CONTROLS
The master section controls affect the subgroup,
mam, and monitor output levels.
The use of subgroups can be demonstrated by this
example: If the input channel PAN controls are set
fully clockwise for all the vocal microphones, then
we will have assigned the SUB R slider as a "vocal
submaster". If we raise or lower the SUB R control
we can set the proper vocal level in the mix while
preserving the input channel balance set among
the vocalists.
1. LEFT SUBMASTER
Controls the volume of the left stereo output
channel. It is also used as a subgroup master.
2. RIGHT SUBMASTER
Controls the volume of the right stereo channel.
It is also used as a subgroup master.
3. MAIN MASTER
The MAIN (monaural) output is an equal mix
of the left and right stereo outputs, the MAIN
MASTER controls the volume of the output.
4. MONITOR MASTER
Controls the volume of the monitor output
signal. The monitor output is a mix of the
individual channel monitor sends.
seven

Phone Gain
BK-1632 STEREO MIXER
21. PHONE GAIN
The PHONE GAIN control sets the level at the
HEADPHONE jack. Any signal selected by
depressing a PFL switch will be monitored through
the headphone jack. With no PFL switch depress¬
ed, the headphone circuit monitors the left and right
sub outputs in stereo.
2J. METER ASSIGNMENT SWITCH
A push-push switch is provided to allow the user
to select the points in the circuit which are
monitored by the LED VU indicators. When the
switch is depressed, the indication will be the audio
level at the left sub and right sub outputs. In the
other (non-depressed) position, signal level at the
main and monitor outputs will be shown.
2K. LED VU INDICATORS
A vertical row of ten light-emitting diodes is used
to indicate signal level at selected points in the
circuit (see assignment switch). This type of display
is free from overshoot (ballistic) problems of
mechanical meters, and is highly visible under poor
lighting conditions. Each indicator is calibrated in
volume units, such that 0 dB corresponds to an out¬
put of 1.23 volts, which is +4 dBu, a standard in
the industry. The mixer provides 16 dB of
headroom above this level for superior sound
reproduction. It may be necessary in some cases
to reduce the sensitivity of equipment fed by the
mixer, such as a power amplifier, to prevent over¬
driving it. A gain control on the amplifier is usually
provided for this purpose. •
2L. SUBGROUP INSERT JACK
This jack provides a convenient point to add signal
processing devices lo the complete left/right
submaster mix. The jack is wired the same as the
channel insert jacks. The output can drive 600 ohms
or greater unbalanced loads up to +20 dBu and
the inputs can accept +20 dBu before clipping.
2M. LAMP CONNECTOR
A BNC type socket is provided on the right hand
side of the mixer panel to accommodate a Littlite '
gooseneck lamp, and allow operation of the board
under dark conditions. The 18-inch long “G” series
is available from many professional sound dealers,
and attaches without tools. The voltage at the
socket is 12.6 V ac at a maximum of 0.2 amps.
2N. POWER SWITCH
The power switch is used to turn on and off the ac
main power.
20. POWER INDICATOR
This LED is illuminated when the ac main power
is on.
2P. PHANTOM POWER SWITCH
This switch turns on and off the phantom power
supply. The phantom power supply provides power
for condenser-type microphones through the
microphone cable. When switched on, it produces
48 volts dc (with 3.4 K-ohm source impedance) at
pins 2 and 3 on all of the microphone input connec¬
tors. Pin 1 (the shield conductor) provides the ground
return path. This will power standard condenser
microphones and will not affect most dynamic
microphones. When switched on or off, the voltage
will ramp slowly up or down; it takes a few seconds
to reach full level. This prevents unwanted transients
from reaching the microphone inputs.
20. PHANTOM POWER INDICATOR
This LED indicates when phantom power is present
at the microphone inputs.
SECTION 3.0
3.0 REAR PANEL INPUT CONNECTORS (Figure 3)
The BK-1632 mixer can accept program material covering
a dynamic range of over lOOdB. Exceptforthe high gain
mic input all of the line inputs can safely accept signals at
least up to + 20 dBu. (See Specifications for details).
Several of the inputs that directly access the mix buses can
be used to stack mixers together without using up an input
channel The stacking group includes the AUX, EFX and
MONITOR inputs. The EFX RET input may be used as
another stacking input. For stereo subgroup stacking set
EFX PAN to L and AUX PAN to R, and use EFX RET and
AUX IN for left and right stacking, respectively.
3A. BALANCED LOW-Z MIC INPUT
A 3-pin XLR-type (“Cannon”) connector is used for
balanced low impedance microphone inputs. The
Mic Input is actively balanced; active balancing
allows elimination of the input transformer (along with
its limitations) while maintaining the RF and hum
rejection of a good transformer coupled input.
It is important that, during operation or testing of the
mixer, all channel faders remain fully down whenever
the mic input is not properly terminated with a
microphone or equivalent 150-ohm source. An open
mic invites the introduction of high noise levels which
could produce lower quality sound or an incorrect
test measurement.
3B. HIGH-Z LINE INPUT
A standard Vi-inch phone jack is used for balanced
or unbalanced line level signals. Examples of line
level signals include most electronic keyboards,
synthesizers, turntables (with appropriate preamps),
tape decks and the line outputs from other mixers. All
input channel controls, including the variable GAIN
control, affect the LINE input Maximum input level
before preamp clipping is 12 V or + 24 dB.
If a sufficient signal level is not possible with the GAIN
control in its furthest clockwise position, the input
signal must then be treated as a mic level signal, and
connected to the microphone input. If necessary, use
an appropriate balancing transformer (EV Model
502CP or equivalent) or a direct box with the
microphone (XLR) input.
eight
‘Littlite is a trademark of C.A.E., Hamburg, Ml

Input Jacks
BK-1632 STEREO MIXER
STACKING
GROUP
3F — MONITOR IN
3E — EFFECTS IN
BK-1632
ELECTRO-VOICE
BUCHANAN, Ml
49107
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Hi
3G — AUX IN —» 1 —3D — AUX RETURN
3C — EFFECTS RETURN
FIGURE 3 — Input Jacks
3C. EFFECTS RETURN
The EFX RET jack accepts line level input signals
which can be set with the EFX RET level and the
EFX PAN front panel controls. This jack may be
used as a stacking input or a second auxiliary input.
3D. AUX RETURN
The AUX RETURN jack is used for signals to be
fed to the subgroup buses. The signal is controlled
by the AUX RETURN and AUX PAN front panel
functions The AUX RETURN is part of the "stack¬
ing group”.
3E. EFFECTS IN
The EFX IN jack will put line level signals directly
onto the effects bus. Crosstalk and buffering pro¬
tection are provided by the input circuit, signal level
is controlled by the external source. The EFX IN is
part of the "stacking group"
3F. MONITOR IN
The MONITOR IN jack will put signals directly onto
the MONITOR bus. Crosstalk and buffering protec¬
tion are provided by the input circuit; signal level
is controlled by the external source. The MONITOR
IN is part of the ‘‘stacking group"
3G. AUX IN
The AUX IN jack will put signals directly onto the
AUX bus. Crosstalk and buffering protection are
provided by the input circuit; signal level is
controlled by the external source. The AUX IN is
part of the "stacking group”
nine

BK-1632 STEREO MIXER
Output Jacks
RIGHT SUBGROUP OUTPUT
4C — MAIN OUTPUT
■ —4B — LEFT SUBGROUP OUTPUT
BK-1632
ELECTRO-VOICE
BUCHANAN, Ml
49107
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4D — MONITOR OUTPUT—' 4F — AUX SEND
4E - EFFECTS SEND
FIGURE 4 — Output Jacks
SECTION 4.0
4.0 REAR PANEL OUTPUT CONNECTORS
(Figure 4)
All output connections are line level, unbalanced, and
made through standard V-i-inch phone lacks. Each out¬
put is capable of driving 600 ohms or more to a max¬
imum level of +20 dBu. (See Specifications for details).
In the BK-1632 mixer all signal paths maintain polarity;
that is, a positive going signal at any input or insert point
will produce a positive going signal at the appropriate
output.
4A. SUB R RIGHT SUBGROUP OUTPUT
This output is derived by summing all of the inputs
(channels and external) assigned to the right
subgroup bus. A PAN control rotated fully
clockwise to the "R" position will assign that signal
only to the right bus.
4B. SUB L LEFT SUBGROUP OUTPUT
This output is the left subgroup equivalent of the
Sub R output.
4C. MAIN OUTPUT
The MAIN output is a 50/50 mix of the right and
left subgroup outputs. Since the BK-1632 is a true
subgroup mixer, all signals that appear in the main
mix must come through the subgroup channels.
4D. MONITOR OUTPUT
The MONITOR output signal is the sum of all of the
input channel monitor sends and the external
monitor input signal.
4E. EFFECTS SEND
The EFFECTS SEND output signal is the sum of
all of the input channel EFX/REV sends plus any
signal coming through the EFX IN.
4F. AUX SEND
The AUX SEND output signal is the sum of all of
the input channel AUX sends (PRE- or POST EQ
and fader) plus any signal coming through the AUX
IN input.
ten

Warranty
BK-1632 STEREO MIXER
SECTION 5.0
5.1 SERVICE AND WARRANTY INFORMATION
5.0 TROUBLESHOOTING
5A. IN CASE OF DIFFICULTY
1. Don’t panic, be systematic, change one thing at a
time. Check the obvious!I! Verify input connections.
2. Check all cables. Many system problems are
caused by poor cables.
3. If there are no lights, check ac power source, power
switch and power fuse.
4. If the problem is one of a "dead” input, verify by
trying the same source in another input.
5. Verify problems by substituting the bad part with
one that works. Do this by moving the cable from
the one that works to one that doesn t.
6. Fuses that blow instantly on turn-on are a sign of
internal distress and mean that you should refer the
unit to "qualified service personnel".
7. Don’t panic, be systematic, change one thing at
a time. Check the obvious!!!
WARRANTY (Limited) — All Electro-Voice products are
guaranteed against malfunction due to defects in
materials and workmanship for a specified period begin¬
ning at the date of original purchase. If such a malfunc¬
tion occurs, the product will be repaired or replaced (at
our option) without charge during the period and under
the limitations stipulated in the data sheet or owner’s
manual for that individual product, if delivered prepaid
to the proper Electro-Voice service facility. The unit will
be returned prepaid. Warranty does not extend to finish,
appearance items, or malfunction due to abuse or opera¬
tion under other than specified conditions, nor does it
extend to incidental or consequential damages. Some
states do not allow the exclusion or limitation of incidental
or consequential damages, so the above exclusion may
not apply to you. Repair by other than Electro-Voice or
its authorized service agencies will void this guarantee.
A list of authorized warranty service centers is available
from Electro-Voice, Inc., 600 Cecil Street, Buchanan, Ml
49107 (AC/616-695-6831); Electro-Voice, Inc., 3810
148th Avenue, N.E., Redmond, WA 98052
(AC/206-881-9555); and/or Electro-Voice West, 8234 Doe
Avenue, Visalia. CA 93291 (AC/209-651-7777). This war¬
ranty gives the customer specific legal rights, and there
may also be other rights which vary from state to state.
FACTORY SERVICE ADDRESS
Electro-Voice, Inc.
Service Department
3810 148th Avenue. N.E.
Redmond, WA 98052
[phone]
eleven

BK-1632 STEREO MIXER
Schematic
SECTION 6.0
6.0 SCHEMATIC
-SERVICE INFORMATION-
1. Resistance values are indicated in ohms unless
otherwise specified.
(K= 1,000, M=1,000,000)
2. Capacitance values are shown in microfarads
unless otherwise noted.
(P=Picofarads)
3. All voltages are refered to ground under the fol¬
lowing conditions.
DC: No signal except where indicated.
AC: Rms
4. - PRECAUTION - a
a) All components marked /:\ must be re¬
placed only with original type specified by the
manufacturer, electro-voice and installed as
the original with spacers and positioned away
from adjacent components where applicable.
b) All soldering must be down in a professional
manner using solder with resin core only.
c) All covers, shield and insulating spacers must
be replaced before returning appliance to
customer.
d) A damaged power supply cord must be re¬
placed before returning appliance to cus¬
tomer.
e) A dielectric test consisting of 1500V AC 60Hz
is to be applied between both blades of the
power supply cord attachment plug and the
exposed conductive surface of the appliance
for a period of not less than one second be¬
fore returning to appliance to customer.
f) The-^MArE- marked resistors are mounting
above the P.C.B. on sleeves.
LM 3915 CONNECTION DIAGRAM
1. LED NO. 1
2. V—
3. V+
4. DIVIDER
5. SIGNAL INPUT
6. DIVIDER
7. REFERENCE OUTPUT
8. REFERENCE ADJUST
9. MODE SELECTOR
10. LED NO 10
11. LED NO 9
12. LED NO 8
13. LED NO 7
14. LED NO 6
15. LED NO 5
16. LED NO 4
17. LED NO 3
18. LED NO 2
twelve