Radio Shack 32-1218 User manual

Owner’s Manual
Please read before using this equipment.
4-Channel Stereo Mixer

2Features

Features
Your RadioShack 4-Channel Stereo Mixer is
a sophisticated desktop control center, per-
fect for mixing sound on four separate chan-
nels from multiple audio sources such as
cassette decks, tuners, CD players, turnta-
bles, or the audio outputs from VCRs or cam-
corders. The mixer is ruggedly constructed
for home or professional use. You can adjust
each audio source's sound level so you can
get the best mix for playing through your
sound system or for recording. Its features
include:
Stereo Phono Input Jacks — for connect-
ing low-level audio sources, such as turnta-
bles with a magnetic cartridge.
Stereo Line Output Jacks — let you con-
nect the mixer's output to your amplifier/re-
ceiver and tape deck so you can play the
sounds from your input sources through your
speaker system, and record them.
Stereo Line Input Jacks — let you connect
most high-level audio sources such as a CD
player, tape deck, tuner, camcorder or VCR.
DJ Microphone Input (MIC 1) Jack — lets
you connect a microphone (not supplied)
with a 1/4-inch (6.35mm) plug.
Auxiliary Microphone Input (MIC 2) Jack
— lets you connect a low impedance micro-
phone (not supplied) with a 1/4-inch
(6.35mm) plug.
CROSS FADER Control — lets you smooth-
ly switch between two input sources such as
a turntable and a tape deck.
Output Level Light Emitting Diode (LED)
Meters — indicates the mixer's total output
signal level.
CUE LEVEL Control — lets you adjust the
headphone's volume level.
MASTER Volume Control — lets you con-
trol the mixer's overall volume level.
BASS/TREBLE Controls — lets you boost
or attenuate bass and treble, for the desired
sound.
BALANCE Control — lets you adjust the
sound balance between the left and right am-
plifier output.
MIC 1, CHANNEL 1, CHANNEL 2, CHAN-
NEL 3, CHANNEL 4 Slide Volume Con-
trols — for fingertip control of sound mixing
and fading.
MIC 2 LEVEL Control — lets you adjust the
microphone's volume.
PHONO 1/LINE1, PHONO 2/LINE 2 Input
Source Selectors — let you easily choose
the desired audio input source for mixing
(CHANNEL 1 and CHANNEL 2).
MONO/STEREO Selector — lets you set the
output to amplifier for stereo or mono.
ASSIGN A/B Input Source Selector — lets
you select the input sources to be mixed by
cross fading.
CUE Audio Source Selector — let you se-
lect the channel for the desired audio input
source, so you can monitor and prepare the
channel before mixing the source.
PHONES Jack — lets you connect a pair of
stereo headphones (not supplied) with a 1/4-
inch plug.
©2001 RadioShack Corporation.
All Rights Reserved.
RadioShack and RadioShack.com are trademarks used by RadioShack Corporation.

3
Preparation

Preparation
PRESETTING THE
CONTROLS
Warning: A sudden high output from the
mixer could damage your hearing, especially
if you use headphones, and might also dam-
age the audio devices connected to the mix-
er's output. Before using the mixer, make
sure you set your receiver/amplifier's volume
control to its lowest volume setting.
Before you connect the AC power source,
make sure you set POWER OFF/ON to OFF.
To avoid sudden and unusable sound out-
puts from any audio devices that you con-
nect to the mixer, be sure to have their power
controls set to off, and any tone controls set
to flat (zero).
CONNECTING THE
OUTPUTS
To play the mixer's output signal through
your sound system, connect one end of an
audio cord (not supplied) to the mixer's AMP
L (white) and R(red) OUTPUT jacks, then
connect the other end to your amplifier/re-
ceiver's left and right line input jacks. Match
left to left, and right to right.
To record the mixer's output signal, connect
one end of an audio cord (not supplied) to
the mixer's REC L(white) and R(red) OUT-
PUT jacks, then connect the other end to
your tape deck's left and right line input jacks
(matching left to left, and right to right).
CONNECTING THE INPUTS
You can connect up to four line-level and up
to two low-level audio input sources to the in-
put jacks on the back of the mixer. You can
connect one microphone to the mixer's front
and another microphone to the back panel.
1. Connect the line-level outputs from up to
four audio sources (such as a CD
player, tape deck, tuner, camcorder, or
VCR) to the LINE 1, LINE 2, AUX 1 and
AUX 2 Land RINPUT jacks (matching
left to left, and right to right).
Caution: Do not connect an audio source
with a line-level output to the low level
PHONO 1 or PHONO 2 L and R INPUT jacks.
Doing so could damage the mixer.
2. Connect the low-level outputs from up to
two audio sources (such as magnetic-
cartridge turntables) to the PHONO 1 and
WARNING: To reduce the risk of fire or
shock hazard, do not expose this product to rain
or moisture.
CAUTION
RISK OF ELECTRIC SHOCK.
DO NOT OPEN.
CAUTION: TO REDUCE THE RISK OF
ELECTRIC SHOCK, DO NOT REMOVE
COVER OR BACK. NO USER-SERVICE-
ABLE PARTS INSIDE. REFER SERVICING
TO QUALIFIED PERSONNEL.
This symbol is intended to alert
you to the presence of uninsu-
lated dangerous voltage within
the product’s enclosure that might
be of sufficient magnitude to con-
stitute a risk of electric shock. Do
not open the product’s case.
This symbol is intended to inform
you that important operating and
maintenance instructions are
included in the literature accom-
panying this product.
!
!

4Preparation
PHONO 2 L and R INPUT jacks (matching
left to left, and right to right).
Note: If you connect magnetic-cartridge
turntables, also connect their ground
wires (usually black or green ) to GND.
3. Connect the DJ's microphone (not sup-
plied) into MIC 1 on the front panel, and
the auxiliary microphone input to MIC 2
on the back panel. Both jacks require a
1/4-inch (6.35mm) plug (not supplied).
CONNECTING POWER
Power the mixer using the supplied 15V 500-
mA AC adapter.
Cautions:
You must use a Class 2 power
source that supplies 15V AC
and delivers at least 500 mA.
Its plug must fit the mixer's AC 15V IN
jack. The supplied adapter meets these
specifications. Using an adapter that
does not meet these specifications
could damage the mixer or the adapter.
• Always connect the AC adapter to the
mixer before you connect it to AC power.
When you finish, disconnect the adapter
from AC power before you disconnect it
from the mixer.
Connect the small barrel plug of the supplied
AC adapter to the AC 15V IN jack on the back
of the mixer and connect the AC plug to a
standard AC outlet.
CONNECTING
HEADPHONES
To listen in privacy or monitor the audio
source inputs so you can locate an exact
passage or section before mixing it, plug a
pair of stereo headphones (not supplied) with
a 1/4-inch (6.35mm) plug into the PHONES
jack on the front panel. Your local Ra-
dioShack store carries a wide selection of
headphones.
Listening Safely
Do not listen at extremely high volume lev-
els. Extended, high-volume listening can
lead to permanent hearing loss. To protect
your hearing when you use headphones, al-
ways follow these guidelines to set the listen-
ing volume.
•Set
CUE LEVEL to the lowest setting
before you begin listening.
• After you put on the headphones, adjust
CUE LEVEL to the desired listening level.
• Once you set the volume, do not
increase it. Over time, your ears adapt
to the volume level, so a volume level
that does not cause discomfort might
still damage your hearing.
Caution: As you begin to mix, do not always
increase volume levels to achieve the proper
balance. You can bring high levels down just
as easily as you can bring low levels up. Lis-
tening at excessive volume levels can dam-
age your hearing.
!

5
Operation

Operation
1. Set the volume levels on the output
devices (amplifier/receiver and tape
deck) to minimum and turn them on.
2. Set the mixer’s POWER OFF/ON to ON.
3. Turn on the input sources to be mixed.
4. Using the mixer requires two basic oper-
ations:
• Presetting the input signal levels (see
“Presetting the Input Signal Levels”)
• Mixing the audio input sources (see
“Mixing the Inputs” on Page 7)
5. After you finish mixing, turn down the
volume on the output audio devices, turn
off the input and output audio devices
(such as amplifiers, or tape decks), then
set the mixer’s POWER OFF/ON to OFF.
PRESETTING THE INPUT
SIGNAL LEVELS
To avoid accidentally overdriving a channel
or prematurely mixing in an audio input
source, make sure you start with the follow-
ing settings.
•Set
Mic1, Channel 1/2/3/ and 4volume
slide controls set to 0
•ASSIGN A and ASSIGN B set to OFF
•TREBLE, BASS, MIC 2 LEVEL, and CUE
LEVEL, set to 0
•MASTER set to about the 5marker.
Note: The MASTER volume control adjusts
the overall volume of MIC 1, MIC 2,CHANNEL
1, CHANNEL 2, CHANNEL 3, and CHANNEL 4.
The mixer uses two output level meters to in-
dicate the total stereo output signal level. For
the best results, each input signal level
should normally be set so the output level
meters never moves over into the red range
(above 0 dB). Distortion is likely to occur on
audio peaks if the meter moves into the red
range.
For monaural output, set MONO/STEREO to
MONO. For stereo output, set MONO/STEREO
to STEREO.
Presetting the Microphone
1. If your microphone has an ON/OFF con-
trol, set it to ON.
2. While continuously talking, adjust MIC 1
(DJ MIC) until you get a reading of up to
0 on both output level meters.
Presetting the Channel 1/2/3/4
Input Sources
Before you mix channels 1, 2, 3, and 4, you
must preset the input signal level for each
channel input source (up to six sources).
Notes:
• It is not necessary to connect an input
source to every jack or mix every input
source connected to the mixer's input
jacks.
• To prevent prematurely mixing audio
sources, set slide volume controls to 0.
• While you adjust the input signal levels
for CHANNEL 1, CHANNEL 2, CHAN-
NEL 3 and CHANNEL 4, either use the
headphones or adjust the receiver/
amplifier's volume to the desired listen-
ing level (not necessarily the final usable
level).

6Operation
• Do not play a quiet portion of music
while you adjust the volume levels, oth-
erwise the volume levels for channels 1,
2, 3, and 4 will be overdriven during the
loud portions of the music.
1. To preset the PHONO 1 or PHONO 2
input source, set PHONO 1/LINE 1 to
PHONO 1 or PHONO 2/LINE 2 to PHONO
2.
2. Start playback of the selected input
source.
3. Slowly slide up the CHANNEL1 or CHAN-
NEL 2 slide volume control until you get
a reading of up to 0 dB on both output
level meters.
4. Stop playback of the selected input
source.
Note: If it is necessary to set the CHAN-
NEL 1 or CHANNEL 2 slide volume con-
trol all the way to 10 in order to get a
reading of up to 0 on the output meter,
then slide CHANNEL 1 or CHANNEL 2
down to about 8and adjust MASTER
upward until you get the reading of 0 dB
on the output level meters.
5. To preset the LINE 1 or Line 2 input
source, set PHONO 1/LINE 1 to LINE 1 or
PHONO 2/LINE 2 to LINE 2. Then repeat
Steps 2–4.
6. To preset inputs for AUX 1 or AUX 2,
start playback of the AUX 1 or AUX 2
input source.
7. Slowly slide up the AUX 1 or AUX 2 slide
volume control until you get a reading of
up to 0 dB on both output meters.
Note: If it is necessary to set the AUX
1or AUX 2 slide volume control all the
way to 10 in order to get a reading of up
to 0 on the output meters, then slide
AUX 1 or AUX 2 volume control down to
about 8and adjust MASTER upward until
you get the reading of 0 dB on the out-
put meters.
8. Stop playback of the input source of
AUX 1 or AUX 2.
Note: If you must readjust the MASTER
volume control during these steps,
remember this affects the level of any
previously preset input sources. You
must readjust those sources until you
get a reading of up to 0 dB.
CHECKING THE SOUND
1. Select one of the input sources, then
start playback of the selected source.
2. Set the slide volume control to the posi-
tion you determined during presetting.
The output meters should show a read-
ing of up to 0 dB.
3. Adjust the receiver/amplifier's volume
until it reaches the desired level for the
location or event where the mixer will be
used (this can vary).
4. Adjust TREBLE or BASS to get the
desired sound (see “Using the BASS
AND TREBLE Tone Controls” on
Page 8).
Note: If adjusting TREBLE or BASS
causes the output meters to exceed
0dBadjustMASTER downward until the
reading returns to 0 dB. Then adjust
your output device (amplifier) volume
accordingly.
5. Stop playback of the selected input
source.
Note: Do not adjust MASTER after checking
the sound.

7
Operation
MIXING THE INPUTS
You can connect input signals from up to six
audio sources, select any two, then mix the
two selected inputs so only one or both play
through your sound system.
Mixing requires three operations:
• Playing one input source
• Monitoring the next input source
• Switching to the next input source
You can play either of the two selected
sources first.
Notes:
• Ensure the slide volume control for the
other input channel source is set to 0.
•CUE allows you to select one source at a
time.
Playin
g
One Input Source
1. Set ASSIGN A to the desired source (1or
3), then set CROSS FADER to A.
Note: If you select 1, set the input source se-
lector for CHANNEL 1 to the preset input
source you want to play first through your
sound system (PHONO 1 or LINE 1).
2. Make sure the first input source's slide
volume control (CHANNEL 1, or CHAN-
NEL 3) is set to the correct preset posi-
tion.
3. Start playback of the source.
Monitorin
g
a Second Input Source
Monitoring a second input source's signal
level requires selecting a second input
source not currently playing, finding the de-
sired section you want to mix, then adjusting
the second source's sound level so it match-
es the volume level of the source currently
playing.
1. Plug headphones into PHONES and then
place them on your head.
Note: You can listen to one channel
through the headphones while the other
channel is playing through the sound
system.
2. Set ASSIGN B to the second input
source (2or 4).
3. Set CUE to the second input source. (In
this example 2 or 4)
Note: If you select 2, set the input source se-
lector to the input source you want to monitor
(PHONO 2 or LINE 2).
4. Start playback of the second input
source you want to play next through
your sound system.
5. If necessary:
•Adjust
CUE LEVEL (headphones vol-
ume) to a comfortable listening level.
• Adjust the second input source vol-
ume slide control to the correct preset
position.
6. Set the second input device to the
desired section of music, then stop or
pause this input device.
Switchin
g
to the Second Input
Source
1. Start playback of the second input
source.
2. When you are ready to play its sound
through your sound system, slide
CROSS FADER from Ato B.
3. Slide CROSS FADER:

8Operation
• To the left to fade in the channel
selected by ASSIGN A and fade out
the channel selected by ASSIGN B.
• To the right to fade in the channel
selected by ASSIGN B and fade out
the channel selected by ASSIGN A.
• To the center to equally mix the two.
Notes on Mixing
• To mix any two inputs selected by the
ASSIGN switches, set each ASSIGN
switch to the desired channel. Then use
CROSS FADER to mix the two.
• Do not slide CROSS FADER to the center
if you want to monitor one channel while
the other is playing. Otherwise, the
sound from the channel you monitor will
also be heard through your sound sys-
tem. Instead, slide CROSS FADER to the
channel you are not monitoring.
For example, to monitor CHANNEL 1
(selected by ASSIGN A) while CHANNEL
2 (selected by ASSIGN B) is playing,
slide
CROSS FADER to B.
USING THE BASS AND
TREBLE TONE CONTROLS
Your mixer has a set of TREBLE and BASS
controls to tailor the frequency sounds for
MIC1, MIC 2, CHANNEL 1 (PHONO 1, LINE
1), CHANNEL 2 (PHONO 2, LINE 2), CHAN-
NEL 3, and CHANNEL 4 to match your
acoustic surroundings or suit your personal
preference.
Rotate TREBLE or BASS toward +12dB to
boost, or toward -12dB to reduce the frequen-
cy sounds.
Note: If you set the control to 0 (center) posi-
tion, the frequency range is unaltered (flat).
SETTING THE SOUND
BALANCE
BALANCE lets you adjust the sound balance
between the left and right speakers. If your
speakers are properly positioned and your
listening area is centered between the
speakers, the center setting of the control is
usually the best.
If the sound seems to be louder from one
speaker, adjust BALANCE until the sound
seems to be coming from a point midway be-
tween the speakers.

9
Troubleshooting

Troubleshootin
g
With proper care and handling, your mixer should give you years of trouble-free service. How-
ever, if your mixer is not working properly, follow these suggestions to see if you can eliminate
the problem. If you cannot, take the mixer to your local RadioShack store for assistance.
CARE
Keep the mixer dry; if it gets wet, wipe it dry
immediately. Use and store the mixer only in
normal temperature environments. Handle
the mixer carefully; do not drop it. Keep the
mixer away from dust and dirt, and wipe it
with a damp cloth occasionally to keep it
looking new.
Modifying or tampering with the mixer’s inter-
nal components can cause a malfunction
and might invalidate its warranty. If your mix-
er is not performing as it should, take it to
your local RadioShack store for assistance.
Problem Possible Solution
Nothing works. Checks the AC power connection. Make sure the AC out-
let is working.
Check all the connections to the system (amplifier/
receiver, input sources, and so on).
Check the AC adapter.
No signal from an audio input source. Make sure the source’s power is turned on.
Check the mixer’s and the source’s control settings.
Check the connection between the mixer and the input
source.
Hum from PHONO sources. Make sure the turntable’s ground wire (usually black or
green) is connected to GND on the back of the mixer.
Hum from other input sources. Make sure there are no low-level inputs connected to the
LINE input jacks.
Feedback. Move the microphone further away from the output
speakers or use a unidirectional microphone.

10 Specifications

Specifications
Input Sensitivity/Impedance
MIC 1 (DJ MIC) .................................................................................. 1.5 mV, 600 ohms, Unbalanced
MIC 2 .................................................................................................. 1.5 mV, 600 ohms, Unbalanced
PHONO 1, PHONO 2 .................................................................................................. 3 mV/50 kohms
LINE 1, LINE 2, AUX 1, AUX 2 ................................................................................ 150 mV/27 kohms
Output Level
Main Out.........................................................................................................................1.5V/10 kohms
Record ..................................................................................................................... 150 mV/10 kohms
Frequency Response .............................................................................................. 20 – 20k Hz ± 3dB
S/N Ratio (for 1 kHz)
MIC1, MIC 2 ................................................................................................................................. 55dB
PHONO 1, PHONO 2.................................................................................................................... 65dB
LINE 1, LINE 2, AUX 1, AUX 2 ..................................................................................................... 70dB
Distortion
MIC1, MIC 2 ............................................................................................................................... 0.30%
PHONO 1, PHONO 2 ................................................................................................................. 0.08%
LINE 1, LINE 2, AUX 1, AUX 2 ................................................................................................... 0.05%
Tone Control............................................................................................................................ Treble ± 12dB
Bass ± 12dB
Power Source .......................................................................................................................AC 15V, 500mA
Dimensions (HWD) .................................................................................................. 2 3/8×14 3/16 ×8 9/16 in
(60.3 ×360.4 ×217.5 mm)
Weight .........................................................................................................................................3 lbs 6.1 oz
(1.46 kg)
Accessory ............................................AC Adapter (Input 120V AC 60 Hz 16.5W, Output 15V AC 500 mA)
Specifications are typical; individual units might vary. Specifications are subject to change and improve-
ment without notice.

11
Notes

Notes

32-1218
04A01
Printed in China
RadioShack Corporation
Fort Worth, Texas 76102
Limited Ninety-Day Warranty
This product is warranted by RadioShack against manufacturing defects in material and workman-
ship under normal use for ninety (90) days from the date of purchase from RadioShack company-
owned stores and authorized RadioShack franchisees and dealers. EXCEPT AS PROVIDED
HEREIN, RadioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED WARRANTIES,
INCLUDING THOSE OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE,
ARE LIMITED IN DURATION TO THE DURATION OF THE WRITTEN LIMITED WARRANTIES
CONTAINED HEREIN. EXCEPT AS PROVIDED HEREIN, RadioShack SHALL HAVE NO LIABIL-
ITY OR RESPONSIBILITY TO CUSTOMER OR ANY OTHER PERSON OR ENTITY WITH RE-
SPECT TO ANY LIABILITY, LOSS OR DAMAGE CAUSED DIRECTLY OR INDIRECTLY BY USE
OR PERFORMANCE OF THE PRODUCT OR ARISING OUT OF ANY BREACH OF THIS WAR-
RANTY, INCLUDING, BUT NOT LIMITED TO, ANY DAMAGES RESULTING FROM INCONVE-
NIENCE, LOSS OF TIME, DATA, PROPERTY, REVENUE, OR PROFIT OR ANY INDIRECT,
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, EVEN IF RadioShack HAS BEEN AD-
VISED OF THE POSSIBILITY OF SUCH DAMAGES.
Some states do not allow limitations on how long an implied warranty lasts or the exclusion or limita-
tion of incidental or consequential damages, so the above limitations or exclusions may not apply to
you.
In the event of a product defect during the warranty period, take the product and the RadioShack
sales receipt as proof of purchase date to any RadioShack store. RadioShack will, at its option, un-
less otherwise provided by law: (a) correct the defect by product repair without charge for parts and
labor; (b) replace the product with one of the same or similar design; or (c) refund the purchase
price. All replaced parts and products, and products on which a refund is made, become the prop-
erty of RadioShack. New or reconditioned parts and products may be used in the performance of
warranty service. Repaired or replaced parts and products are warranted for the remainder of the
original warranty period. You will be charged for repair or replacement of the product made after the
expiration of the warranty period.
This warranty does not cover: (a) damage or failure caused by or attributable to acts of God, abuse,
accident, misuse, improper or abnormal usage, failure to follow instructions, improper installation or
maintenance, alteration, lightning or other incidence of excess voltage or current; (b) any repairs
other than those provided by a RadioShack Authorized Service Facility; (c) consumables such as
fuses or batteries; (d) cosmetic damage; (e) transportation, shipping or insurance costs; or (f) costs
of product removal, installation, set-up service adjustment or reinstallation.
This warranty gives you specific legal rights, and you may also have other rights which vary from
state to state.
RadioShack Customer Relations, 200 Taylor Street, 6th Floor, Fort Worth, TX 76102
We Service What We Sell 12/99