U.S. Audio Mix8s Specifications

8
99 Ling Road . Rochester, NY 14612 . Phone 716 663-8820 . Fax 716 865-8930 . Email: Sales@whirlwindusa.com . http://www.whirlwindusa.com
INTRODUCTION THEORY OF OPERATION
Thank you for selecting the U.S. Audio Mix 8S stereo line mixer. This The U.S. Audio Mix 8S is a stereo line level eight channel mixer with
mixer represents an excellent value for monitoring and mixing multiple separate left and right signal paths. Each of the 8 inputs has left and right
stereo feeds, delivering the highest quality audio performance in a balanced 1/4" input jacks. For mono input, the right jack can be used
compact one rack space package. The U.S Audio Mix 8 is a true stereo 8 alone and it will "Y" the signal to both left and right busses. The signal is
channel line level mixer, designed for use in broadcast production, as a actively balanced through differential buffer amps and sent to gain
studio mixdown / monitor mixer for multitrack recorders or in countless circuits. Each channel has a dual element level control with a gain range
other applications. Features include stereo channel level controls, and a of -60 to +18 dBm, allowing user control over a wide range of input audio
headphone monitor circuit with individual volume control. The Mix 8S levels. Unity gain is at the 12 o'clock position for both channel volume
can provide up to 36 dB of gain, with a professional quality signal to noise and the master volume.
ratio and full frequency response. All connections are made through Signals from individual channels are summed together and delivered to
balanced 1/4" tip-ring-sleeve jacks. both master gain stages and to the headphone driver circuit. The left and
right master outputs are controlled by a stereo volume pot which has a
gain range of -60 to +18 dBm. The 60 dBm of attenuation turns off the
audio signal at the main outputs if necessary.
The Mix 8S headphone circuit monitors the left and right busses and will
drive stereo headphones with impedances greater than 30 ohms. The
UNPACKING
front panel stereo 1/4" headphone jack has a volume control with a
range of -60 to +18 dB. The signal going into the headphone circuit is a
pre master fader.
Careful layout of the circuit board and a star grounding scheme ensure
no internal ground loops between channels and / or sections of circuitry.
Using low noise components, noise is 81 dB below 0 dB at unity gain,
U.S. Audio has made every effort to ensure that your equipment is with one channel up and 78 dB below 0 dB will all channels up at unity.
received in the same perfect condition it was when it left the factory. The Mix 8s utilizes a dual transformer power supply which is configured
with internal jumpers for 120 VAC 60 Hz or 230 VAC 50 Hz operation.
Please inspect your product for any signs of damage during shipping
There is an internal fuse on the hot side of the AC cord, and the power
and report them to your dealer so that a claim can be made to the
switch makes and breaks both the hot and neutral legs of the AC cord.
shipper. We recommend that you save your packing material for use in
the unlikely event that you need to return your equipment for service.
S
1
1
CHANNEL
5
4 6
8
S 3 7
2
8
1 9
0 10
VOLUME
POWER
9 8
CONTROLS AND FUNCTIONS
1. INPUT LEVEL CONTROL varies the amount of signal sent to the
master left and right busses through a range of 60 dBm attenuation at full
off to +18 dBm of gain full on.
2. MASTER VOLUME CONTROL determines the amount of signal from
the summing amps that is fed to the left and right outputs. This also has a
gain range of -60 to +18 dBm.
3. HEADPHONE VOLUME CONTROL varies the signal at the
headphone jack. The signal going into the headphone circuit is pre
master fader and independent of the master volume pot.
4. POWER LED indicates that the unit is turned on.
5. HEADPHONE JACK drives stereo headphones with impedances
greater than 30 ohms and is wired with left to tip and right to ring.
6. LEFT AND RIGHT INPUT JACKS for each of the 8 channels are
balanced 1/4" TRS. For mono input, the right jack can be used alone and
it will "Y" the signal to both inputs.
7. LEFT AND RIGHT MAIN OUT JACKS controlled by the front master
volume pot are balanced 1/4" TRS and will drive balanced or
unbalanced inputs.
8. POWER SWITCH connects AC to the transformer primary and the
front panel LED indicates that the unit is working. Both sides of the AC
line are switched and the main fuse is located on the circuit board inside
the unit.
9. POWER CORD has a standard 15 amp plug for 120 VAC and has no
plug on the Mix 8S 230 VAC model. Black is line, white is neutral and
green is earth.
2 3 4 5
CHANNEL CHANNEL CHANNEL CHANNEL CHANNEL
5 5 5 5 5
4 6 4 6 4 6 4 6 4
3 7 3 7 3 7 3 7 3
2 2 2 2 2
8 8 8 8
1 9 1 9 1 9 1 9 1
8
0 10 0 10 0 10 0 10 0
VOLUME VOLUME VOLUME VOLUME VOLUME
R WARNING
: TO PREVENT ELECTRIC SHOCK DO NOT
REMOVE COVER. NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
U.S. AUDIO
CAUTION 8
A DIVISION OF WHIRLWIND INC : TO REDUCE THE RISK OF FIRE AND
ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO
ROCHESTER, NY USA
ANY TYPE OF RAIN OR MOISTURE.
L
ATTENTION : DEBRANCHER AVANT D'OUVRIR
120 Vac at 60 Hz
230 Vac at 50 Hz
25 watts MAX ALL CONNECTORS BALANCED
MAIN OUT STEREO TIP+, RING-, SLEEVE GND
7 6
TYPICAL OF 8
+
LEFT
TOP _
RIGHT +
MONO
_
BOTTOM
NEG
HOT
¼ AMP
SLOW
BLOW
CHASSIS GROUND
2 3 4 5
6 7 8
CHANNEL CHANNEL MASTER PHONES
5 5 5 5
6 4 6 4 6 4 6 4 6
U.S.Audio
7 3 7 3 7 3 7 3 7
2 2 2
8 8 8 8
9 1 9 9 1 9 1 9
PHONES
10 0 10 0 10 0 10 0 10 PHONES
VOLUME VOLUME VOLUME VOLUME
PWR
LEFT
S
7 6 5 4 3 2 1
RIGHT/
MONO
INPUTS
BLOCK DIAGRAM
+
BUSS
LEFT _
MASTER
SUM AMPS
VOLUME
+
BUSS
RIGHT _
HEAD
PHONES
BUSS HEAD
LEFT PHONE
VOLUME
CHANNEL
VOLUME
BUSS
RIGHT
POWER LED
+18 VOLTS DC
POWER
JUMPERS
FOR
120/230
VOLTS
-18 VOLTS DC
SPECIFICATIONS
Frequency Response + .5 dBm 20 Hz to 20 kHz
+3 dBm 7 Hz to 58 kHz
Input Impedance
All Inputs 20 k ohm Unbalanced
Maximum Input Level
All Inputs +21 dBm
Output Impedance
All Inputs 100 ohm
Maximum Output Level +22 dBm
Rise Time 6 uS
Stereo Separation >60 dBm
30 ohms
Minimum Headphone Impedance
Noise
One Channel Unity Gain -81 dBm
-78 dBm
All Channel Unity Gain
<.01% 20-20kHz
T.H.D. + n
-60 to +18 dBm
Range of Gain Controls
Mute Attenuation 60 dBm
Total Gain 36 dBm
Power Consumption .15 Amps Max. A.C. At 120 VAC
.15 Amps Max. A.C. At 230 VAC
+105 VAC at 120 V nominal
AC Dropout Voltage
+205 VAC at 230 V nominal
LEFT Size Single Space Standard E.I.A Spec
OUT 19.0"(482.6mm) Width
6.0"(152.4mm) Depth
1.75"(44.45mm) Height
Weight
RIGHT
Shipping Weight 7.5 lbs (3.40 kg)
OUT
6.0 lbs (2.72 kg)
Unit Weight
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
U.S.Audio
TM