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OPERATIONS MANUAL
MEASUREMENT VALUE
Frequency Response (Line) unity gain
Frequency Response (Mic) 40 dB gain
±.25 dBV 20 Hz - 20 kHz
±.35 dBV 20 Hz - 20 kHz
THD + N Line Mode unity gain
THD + N Mic Mode 40dB gain
<.0035% 20 Hz - 20 kHz
<.012% 20 Hz - 20 kHz
Equivalent Input Noise -120 dBV
Rise Time 4.1 uSec
Total Gain mic mode full gain 70 dBV
Gain of Microphone Preamp Mic/Line switch (in) +32 dBV
Range of input level pot -63 to +20 dBV
Range of master level pot -70to +17 dBV
Common Mode Rejection of Input (Mic) >63 dB
Maximum Input level Line +21 dBV; Mic –11 dBV
Input Impedance Mic 1.3 kOhms; Line 8.8 kOhms
Isolation between input channels Line at unity gain; 72 dB @ 1 kHz
Maximum output level +26 dBV balanced
Output Impedance 200 Ohms balanced; 100 Ohms each leg
Noise at unity gain (Line) -88 dBV
Noise at 40 dB gain (Mic) -79 dBV
Dynamic Range 111 dBV
Treble Control ±15 dBV @ 16kHz, shelving
Bass Control ±15 dBV @ 20 Hz, shelving
Tone Control ±12 dBV @ 2 kHz, peaking
LED thresholds +18, 22 dBm bal; 16 dBm unbal
+ 8, 12 dBm bal; 6 dBm unbal
0, 4 dBm bal; -2 dBm unbal
- 24, -20 dBm bal; -26 dBm unbal
Phantom Power 48 VDC
Power consumption .13 Amps AC at 120 VAC max.
.09 Amps AC at 120 VAC min.
Power requirements 120 VAC 60 Hz US model
240 VAC 50 Hz Export model
Internal Mains fuse .5 Amp Slo-blo type 3AG US model
.25 Amp Slo-blo 3AG Export model
AC dropout voltage 95 VAC
Size 1.75” H x 19” W x 6” D
Unit Weight 5.3 lbs
Shipping Weight 7 lbs
MIX-7
STEREO MIXER
INTRODUCTION: Thank you for selecting the Whirlwind MIX-7 stereo mic/line mixer. The MIX-7 is a
versatile stereo mixer, combining four mono mic/line inputs and three stereo line inputs, in a
compact, one-rack space package. Features include stereo/mono switching and a tone control on
each of the mic/line inputs, two place master EQ, metering and a stereo/mono switch on the main
outputs. This mixer represents an excellent value, delivering the highest quality audio performance
at a low cost.
MIX-7 SPECIFICATIONS
UNPACKING: Whirlwind has made every effort to ensure that your equipment is received in the
same perfect condition it was when it left the factory. Please inspect your product for any signs of
damage during shipping and report them to your dealer so that a claim can be made to the shipper.
We recommend that you save your packing material for use in the unlikely event that you need to
return your equipment for service.
WARRANTY: This product is guaranteed to be free from defects in materials and workmanship to the original purchaser
for a period of 5 years from the date of purchase. Should service be required, return the unit postage prepaid along with
the original sales receipt to:
whirlwind
Attention - Repair
99 Ling Road
Rochester, New York 14612
The warranty on this product shall not apply to defects or damage resulting from abuse, abnormal use or from repairs or
modifications performed by anyone other than whirlwind. If it is determined a manufacturing defect has occurred,
whirlwind will repair or replace the unit at our option and pay the postage back to you.
99 Ling Road - Rochester, NY 14612
800-733-9473 / 585-663-8820 Fax: 585-865-8930
whirlwind
www.whirlwindusa.com
sales@whirlwindusa.com
MIX-7 BLOCK DIAGRAM
3.5 MM
ON BACK
BUSS LEFT
10 k input Z
CHANNEL 5 & 6
CHANNEL 1
CHANNEL 2
COMBO
COMBO
STEREO
VOLUME
BUSS RIGHT
MIC/LINE
m
l
m
l
32 dB GAIN IN MIC
MIC/LINE
m
l
m
l
32 dB GAIN IN MIC
+48 VDC
+
-
+48 VDC
+
-
3.5 MM
ON FRONT
10 k input Z
CHANNEL 7
-20 TO +20
dB GAIN
-20 TO +20
dB GAIN
BASS/TREBLE
CUT/BOOST
BASS/TREBLE
CUT/BOOST
STEREO
VOLUME
BUSS LEFT
1/2 MONO
BUSS RIGHT
BUSS LEFT
BUSS RIGHT
BUSS RIGHT
BUSS LEFT
CHANNELS 1 AND 2
CHANNELS 3 AND 4
BUSS LEFT
STEREO/MONO
BUSS RIGHT
FUSE
LINE
SUM
POWER ON/OFF
RF FILTERING
AC CORD
NEU
GROUND
LIFT
POWER ON/OFF
MASTER
MASTER
BASS
TREBLE
STEREO
100 HERTZ 100 K HERTZ
INTERNAL JUMPERS
TOROID
STEREO
MASTER
VOLUME
STEREO
RIGHT
LEVEL LEDs
+18
-24
+8
0
MALE XLR
MALE XLR
LEFT
LEVEL LEDs
+48 VDC
POWER ON
+18
+8
0
-24
+18 VDC
-18 VDC
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THEORY OF OPERATION:
Mic/Line Inputs: Mic or line level signals are input to the MIX-7 via Neutrik Combo XLR/TRS connectors. Phantom
power is present on the female XLR connector only when the mic/line switch for that channel is in the MIC position.
Phantom power is never present at the TRS input. The MIC switch position adds 32 dB of fixed gain on both of the input
connectors allowing for maximum connectivity versatility. By using +/- 18 power rails, the MIX-7's inputs have high
headroom, low noise and low distortion. After the mic/line switch, the signal passes through the volume control, with a
gain range of –63 to +20 dB. The –63 dB of attenuation also serves as off or mute in most applications. This ensures no
matter what input level is presented to the mic/line inputs, the volume can be adjusted to the desired level. After the
volume control, the signal is next presented to a unique tone control, designed to add clarity to the human voice. This
mid range peak/cut filter boosts or cuts 2 kHz by 12 dB, which greatly affects the voice band. The final stages are the
Left/Right bussing switches; one for channels 1 and 2, and a second for channels 3 and 4. In L | R mode for channels 1
and 2, channel 1 is placed on the left output of the mixer, and channel 2 on the right side. This configuration is
commonly used to connect 2 balanced sources in stereo. With the switches in L+R mode for channels 1 and 2, both
inputs are placed in mono on the left and right sum busses. Switches for channels 3 and 4 work the same way. This
allows use with 4 mic or line level balanced inputs (XLR or TRS), 2 pairs of stereo line level inputs or 2 mics and 1
stereo source. Care was taken so that when the signals are summed to mono, in phase audio will remain at the same
level. This allows the user to sum stereo signals on the fly without level changes.
Line Inputs: There are 3 sets of stereo line inputs via RCA jacks on the back panel. Inputs 5 and 6 also have a 3.5 mm
input on the rear and channel 7 has a 3.5 mm normalled input on the front panel. With channels 5 and 6 use either the
RCA or 3.5 mm inputs. On input 7, plugging into the 3.5 mm jack on the front panel disconnects the RCA inputs on the
back. This is intended for patching music players on the fly. All 3 line inputs are first buffered to maintain uniform
impedance to the source, and then pass through a stereo volume control with a wide range of –63 to +20 dB. The –63
dB of attenuation also serves as off or mute in most applications. This ensures no matter what input level is presented
to the line inputs, the volume can be adjusted to the desired level.
Sum buss: The signals from all seven sets of inputs are summed to master left and right signals at the sum buss.
Master Bass and Treble controls: These stereo tone controls usually remove the need for an equalizer in the audio
system. With +/- 15 dB of boost or cut at 20 Hz for the bass and at 16 kHz for the treble, most tone shaping tasks can be
done with these controls.
Stereo/Mono output switch: The MIX-7 can be used as stereo or in mono with the left and right outputs combined.
Care was taken so when the signals are summed to mono, in phase audio will remain at the same level. This allows the
user to sum stereo signals on the fly without level changes.
Output Level control: This has a wide range of –70 to +17 dB allowing the user to dial in any volume needed. The –70
dB of attenuation also serves as off or mute in most applications.
Output VU level LEDs: Two sets of 4 LEDs offer visual indication of output level. The reference numbers represent
nominal levels unbalanced. For balanced outputs the levels are approximately 6 dB higher.
Power Supply: The MIX-7 uses a toroidal power transformer for optimal sound quality. There are solder type internal
jumpers, which configure the dual primary of the transformer for 120 VAC 60 Hz or 230 VAC 50 Hz operations. The hot
and neutral incoming AC lines are completely disconnected when the power is switched off. A power LED indicates the
unit is on.
AUDIO SHIELD TO EARTH switch: The switch on the back panel connects the audio grounds to the earth ground on
the AC cord. Use this switch to break ground loop hum between the MIX-7 and other AC powered equipment when
audio grounds have multiple return paths.
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STEREO
MONO
8
3
2
1
9
LEFT RIGHT
5
4
0
+18
6
+8
7
8
-24
9
VU
10
2 1
MIC
LINE
11
POWER
0
MIC/LINE
INPUTS
MIC
LINE
13
30 WATTS MAX
115/230VAC 60/50Hz
18
1
2
5
4
6
1 2
3
7
2
8
1
9
0
10
MIX 7 STEREO MIC/LINE MIXER
POWER
17
16
3
STEREO
L
TONE TONE
L+R
AUDIO
SHIELD
TO
EARTH
LIFT
MIC/LINE INPUTS STEREO LINE INPUTS
VOLUME VOLUME VOLUME VOLUME VOLUME VOLUME
5
4
3
R
2
1
0
5
4
6
10
3
7
2
8
1
9
0
BALANCED OUTPUTS
6
STEREO
3 4 5 6 7
L
R
7
8
9
TONE TONE
L+R
10
R
WHIRLWINDUSA.COM MADE IN USA
5
4
3
2
1
0
L
6
7
8
9
10
7
DISCONNECTS RCA
3
2
1
FRONT INPUT
5
4
6
0
10
L
R
15
5
4
6
3
7
2
8
1
9
0
10
STEREO LINE INPUTS
6 5
TIP = LEFT
14
7
8
9
RING = RIGHT
5
6
4
5
4
6
3
7
2
IN 7
8
TIP=L
1
9
RING=R
0
10
4 3
MIC
LINE
7
MIC/LINE
INPUTS
LINE
OUTPUT
TREBLE VOLUMEVOLUME
0
-15
+15
MIC
BASS
0
-15
+15
CONTROLS AND CONNECTIONS:
1
MIC/LINE INPUTS (4) pots vary the amount of signal sent to the left and right output busses through a range of -63 dB attenuation at
full off to +20 dB of gain full on.
2
TONE (4) pots on each Mic/Line input have a ± 12dB boost and cut range at 2 kHz. This can be very helpful in enhancing clarity in mic
signals or reducing feedback.
3
STEREO L-R (2) switches assign the input signals to the output busses. In the L--R position, inputs 1 and 2 or 3 and 4 are sent to the
left and right busses (stereo). The L+R positions assign the corresponding input pairs to both left and right output busses (mono).
4
STEREO LINE INPUTS (3) pots vary the amount of signal from the line inputs sent to the left and right output busses through a range
of 63 dB attenuation at full off to +20 dB of gain full on.
5
IN 7 front panel stereo jack is a 3.5mm type that allows convenient access for connection of a portable music player. Using this jack
automatically disconnects the rear panel RCA inputs.
6
OUTPUT BASS pot is a shelving type tone control with ± 15 dB of range at 20 Hz. This is useful for adding bass in a sound system or
reducing wind noise on microphones in outdoor applications.
7
OUTPUT TREBLE pot is a shelving type tone control with ± 15 dB of range at 10 kHz. This is useful for adding brightness to music
sources or reducing sibilance with some microphones.
8
OUTPUT STEREO/MONO switch determines whether the left and right outputs have separate signals or both have a mono summed
signal.
9
OUTPUT VOLUME pot adjusts the amount of signal from the summing amps that is fed to the left and right outputs. This also has a
gain range of -70 to +20 dB.
10
VU LED meters are precisely calibrated and span a range of –24 to +18 dB, measured unbalanced with the input switch in Line mode,
at either the ¼” or XLR output. (Add 6 dB for balanced output.)
11
POWER LED indicates that the unit is turned on.
12
MIC/LINE INPUTS (4) are combination XLR and balanced ¼” TRS jacks. Either jack can be used for mic or line input signals. The XLR
has 48 Volt phantom power applied to it when the Mic/Line switch is in Mic mode. Phantom power is always blocked from the ¼” TRS
input jack.
13
MIC/LINE switches (4) are connected to an active circuit that adds 32 dB of gain in the MIC position. This gain is applied to both the
XLR and ¼” jacks.
STEREO LINE INPUTS (3 x 2) RCA jacks are white (left) and red (right). On inputs 5 and 6 there are 3.5mm jacks wired in parallel with
14
the RCA jacks. Only use one set of inputs at a time. On input 7 there is a 3.5mm jack is on the front panel that disconnects the RCA
input when a plug is inserted in the front. The 3.5mm jacks are wired tip to left and ring to right.
15
BALANCED OUTPUTS XLR and ¼” TRS jacks are wired in parallel with tip to pin 2 and ring to pin 3. Use only one set of outputs at a
time. Maximum output level is +26 dB balanced. Balanced or unbalanced cables can be connected to either output. When using the
XLR unbalanced, wire pin 2 as hot and leave pin 3 open.
MIX-7
STEREO MIXER
12
16
AUDIO SHIELD TO EARTH switch disconnects the audio ground path from the electrical chassis ground in the Lift position.
POWER switch connects AC to the transformer primary and the front panel LED indicates that the unit is working. Both sides of the AC
17
line are switched and the main fuse is located on the circuit board inside the unit.
18
Power Cord has a standard 15 Amp plug for 120 VAC and has no plug on the MIX -7X 230 VAC model. Black is line, white is neutral
and green is earth.
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