Whirlwind MIX16 Manual

INTRODUCTION

THEORY OF OPERATION

Thank you for selecting the U.S. Audio Mix 16 line mixer. This mixer The U.S. Audio Mix 16 is a stereo line level mixer with 1/4" tip-ring-
represents an excellent value for monitoring and mixing multiple feeds, sleeve input jacks. Each input signal is actively balanced through a
delivering the highest quality audio performance in a compact one rack differential buffer amp and sent to the channel gain circuit. Each channel
space package. The U.S Audio Mix 16 is a 16 channel balanced line level has a level control with a gain range of -60 to +18 dBm, allowing
mixer, designed for use in broadcast production, as a studio mixdown / operation with a wide range of input volume levels. Unity gain is at the 12
monitor mixer for multitrack recorders or in countless other applications. o'clock position for both channel volume and the master volume.
Features include channel level controls, and a headphone monitor Signals from individual channels are summed together and delivered
circuit with individual volume control. The Mix 16 can provide up to 36 dB to the master gain stages and to the headphone driver circuit. There are
of gain, with a professional quality signal to noise ratio and full frequency two main output jacks controlled by a single volume pot which has a gain
response. All connections are made through balanced 1/4" tip-ring- range of -60 to +18 dBm. Each output jack is balanced (tip is positive)
sleeve jacks. and driven by a separate circuit. The 60 dBm of attenuation turns off the
audio signal at the main outputs if necessary.
The Mix 16 headphone circuit monitors the summing buss and will
drive stereo headphones with impedances greater than 30 ohms. The
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

UNPACKING

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, with one channel up and 76 dB below 0 dB with all channels up at
unity.
The Mix 16 utilizes a dual transformer power supply which is
U.S. Audio has made every effort to ensure that your equipment is
configured with internal jumpers for 120 VAC 60 Hz or 230 VAC 50 Hz
received in the same perfect condition it was when it left the factory.
operation. There is an internal fuse on the hot side of the AC cord, and
Please inspect your product for any signs of damage during shipping
the power switch makes and breaks both the hot and neutral legs of the
and report them to your dealer so that a claim can be made to 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.
1
1 2 3 4 5 6 7
CHANNEL CHANNEL CHANNEL CHANNEL
5 5 5 5 5 5 5
16
0 10 0 10 0 10 0 10 0 10 0 10 0 10 0
VOLUME VOLUME VOLUME VOLUME
WARNING
: TO PREVENT ELECTRIC SHOCK DO NOT
REMOVE COVER. NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
POWER U.S. AUDIO
CAUTION
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.
ATTENTION
: DEBRANCHER AVANT D'OUVRIR
120 Vac at 60 Hz
230 Vac at 50 Hz
25 watts MAX ALL CONNECTORS BALANCED
MAIN OUT MONO
TIP+, RING-, SLEEVE GND
9 8 7

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
TYPICAL 1 OF 16
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. INPUT JACKS for each of the 16 channels are balanced 1/4" TRS.
7. MAIN OUT JACKS controlled by the front master volume pot are
balanced 1/4" TRS and will drive balanced or unbalanced inputs. Each
jack has a separate drive circuit.
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.
8 9 10 11 12 13 14 15 16
CHANNEL CHANNEL CHANNEL CHANNEL MASTER
5 5 5 5 5 5 5 5 5
10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0
VOLUME VOLUME VOLUME VOLUME VOLUME
15 13 11 9 7 5
16 14 12 10 8 6
INPUTS
6

BLOCK DIAGRAM

BUSS
MASTER
VOLUME
CHANNEL
VOLUME
+
BUSS
_
HEADPHONE
VOLUME
POWER LED
POWER
NEG

JUMPERS

FOR
HOT
120/230
VOLTS
¼ AMP
SLOW
BLOW
CHASSIS GROUND

SPECIFICATIONS

2 3 4 5
Frequency Response + .5 dBm 20 Hz to 20 kHz
+3 dBm 7 Hz to 58 kHz
PHONES
Input Impedance
5 5
U.S.Audio All Inputs 20 K ohm Unbalanced
Maximum Input Level
All Inputs +21 dBm
PHONES
10 0 10 PHONES
PHONES
VOLUME
PWR
Output Impedance
100 Ohm
All Inputs
Maximum Output Level +22 dBm
3 1
Rise Time 6 uS
Stereo Separation >60 dBm
4
2
One Channel Unity Gain -81 dBm
All Channel Unity Gain -76 dBm
T.H.D. + n .015%
Range of Gain Controls -60 to +18 dBm
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
Size Single Space Standard E.I.A Spec
19.0"(482.6mm) Width
+
6.0"(152.4mm) Depth
OUT 1
_ 1.75"(44.45mm) Height
Weight
7.5 lbs (3.40 kg)
Shipping Weight
Unit Weight 6.0 lbs (2.72 kg)
+
OUT 2
_
MIX 16 MONO REVISION 2.1
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
HEAD
PHONES
99 Ling Road
Rochester, NY 14612
Phone 716 663-8820
Fax 716 865-8930
Email: Sales@whirlwindusa.com
http://www.whirlwindusa.com
U.S.Audio
+18 VOLTS DC
-18 VOLTS DC
TM