U.S. Audio
whirlwind
OPERATIONS MANUAL
Mix 6
STEREO MIXER
UNPACKING
INTRODUCTION
US Audio has made e\'erv effort to ensure that your equipment is received
in the same perfect condition it was in when it left the factory. Please
inspect your product for any signs of damage during shipping and report
them to your dealer so that he can present a claim to the shipper. \Ve
recommend that you save your packaging material for use in the unlikely
event that you need to return your equipment for service.
Thank you for selecting the US Audio Mix 6. The Mix 6 delivers the ultimate
in sonic performance for the most demanding professional mic and line
mixing applications. Utilizing the Analog Devices 2017 IC, a carefully
wound toroidal power transformer, trUe star grounding, plus many other
design features, the Mix 6 has a working signal to noise ratio (S/N) of 92db
with 22dB headroom at unity gain! At 40dB of gain the Mix 6 holds a working
S/N of 85dB making it ideally suited for production with digital recording
media. The Mix 6 can provide up to 76dB of gain, with a professional quality
signal to noise ratio and still have 10 to 15dB of headroom. Other features
include 2 stereo aux inputs, one of which can be used as a separate monitor
input, a stereo peak limiter, low cut filters and a headphone circuit. \Vith a full
complement of hook-up hardware, the Mix 6 is capable of handling any
configuration of line or mic level signals as well as any combination of
balanced or unbalanced XLR and 1/4” connectors.
the “in” position and lifts the signal when “out”. Signal to the headphone switch is
always on.
CONTROLS AND CONNECTIONS
1. Channel Volume Pots control input signals over a range of
7. Master Volume Potsdetermine the amount of signal from the summing amps
that is fed to the output drivers and the meters. These also have a gain range of -60 to
i-2OdBm.
6OdBm attenuation at full off to 2OdBm of gain at full on.
2. Pan Pots aredual pots with center detent, offering over 65dB of stereo isolation
from left to right channel. The center detent allows convenient and accurate setup,
feedingsignal equallytobothchannels.
8. LED dB Indicators are precisely calibrated at 3dB increments and span a range
of -15 to +l2dBm measured unbalanced at the 1/4” output. The output of the XLR,
withthe switchinLine mode, is6dBgreater.
3. Low frequency Cut Switch for reduction of wind noise, etc. The cutoff
9. Stereo Peak Limiteris pre master fader and is switchable in or out of the signal
path. Threshold is set at 0dB and limiting up to 15dB is possible. The left and right
LEDs on the front panel illuminate when the limiter is working and get brighter as
limiting increases. Attack time is fast and the ratio is approximately 4:1.
frequency is 120Hz with a 24dB slope.
4. OL (Over Load) LEDilluminates when the level is 3dB below distortion. The
clip circuit senses the signal level at the input diff amp and after the channel gain.
10. Stereo Headphone Circuit consists of a source select switch, a volume
control, a 1/4” TRS headphone jack and will drive any headphones with 20 ohms or
greater impedance. The volume control has a gain range of -60 to +20db. The select
switch feeds either the prefader stereo master signal or the aux 2 postfader signal to
the headphone amplifier.
5. Aux 1 Input Pot controls the rear panel RCA jacks. Aux I is a stereo unbalanced
circuit feeding the left and right busses. This control has a gain range of -60 to -~-
20dB.
6. Aux 2 Input Pot controls the rear panel stereo 1/4” TRS balanced jacks through
a gain range of -60 to +20dB. Postfader signal is fed to the headphone select switch
“mon' position allowing aux 2 to become an external input to the headphone circuit.
The main/off switch routes the aux 2 input signal to the left and right stereo busses in
11. LED Indicators for Phantom Power and Unit Power illuminate
when rear panel switches are activated.
12. Input 1/4 TRS and XLR Jacks are AC coupled through
phantom blocking capacitors with pin 2 being positive wired to tip,
pin 3 being negative wired to ring and pin 1 being common wired to
sleeve.
19. Phantom Power Switch activates 48V DC on channel 1-4 XLR
inputs. Status is indicated by the front panel LED. Each of the mic
inputs is filtered to eliminate crosstalk through the supply rail and
phantom powerisisolatedfrom the TRSjacks.
13. Input MidLine Switch is connected to an active circuit and
turns on 36dB of gain when pushed in to the Mic position. This gain is
appliedtobothinput jacks.
20. Ground Lift Switch connects the audio circuit ground to AC
ground and the chassis of the unit, if desired.
14. Left and rightUnbalanced RCA Jacksfor aux 1 input.
15. Left and rightBalanced 1/4 TRS Jacksfor aux2 input.
21. 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 a mains fuse is located on the circuit board
inside the unit.
16. Output Mic/Line Switches affect only the XLR output jacks by
inserting a 20dB pad across pins 2 and 3 in the Mic position.
22. Power Cord has a standard 15 amp plug for l2OVAC and has no
plug on the Mix 6X 23OVAC models. Black is line, white in neutral
and green is earth.
17. Output Male XLR Jacks are balanced with pin 2 being
positive, pin 3 being negative and pin 1 being audio ground. For
unbalanced operation use pins
I
and
2
leaving pin
3
UNCONNECTED. To internally lift pin 1 from common, open the
unit and cut jumper JMP7 for left or JMP6 for right.
18. Output 1/4 TRS Jack delivers the same signal as the XLR but
has a separate driver circuit providing complete isolation. May be
used either balanced with a TRS plug or unbalanced with a TS plug.
Tipispositive, ringisnegativeandsleeveisaudioground.
INPUT
MIC/LINE
SWITCH
SIGNAL
TO NOISE
RATIO
INPUT
LEVEL
HEADROOM
MAX OUT
RESIDUAL
NOISE
GAIN
10
0
0
Line
Line
Line
Line
Line
Line
Mic
Mic
Mic
Mic
Mic
Mic
Mic
Mic
0
0
12
22
12
12
2
101
91
92
82
82
72
105
95
85
86
76
76
66
68
-91
-91
-82
-72
-62
-59
-89
-89
-85
-76
-76
-66
-66
-58
10
20
30
33
36
36
40
50
50
60
60
70
-10
-10
-20
-20
-30
-40
-40
-50
-50
-60
-60
9
6
16
22
12
22
12
22
12
SPECIFICATIONS
Frequency Response
Line mode
LED Clip Threshold
+19dBm unbalanced
+25dBm balanced
± 3dB, 6Hz to 40kHz
-0.4dB @ 20Hz
-.8dB @ 20kHz
THD+N (Total Harmonic Distortion + Noise)
.005% @ 1kHz
Mic mode
± 3dB, 18Hz to 36kHz
-2.5dB @ 20Hz
-1dB @20kHz
.02% 20Hz to 20kHz
Phantom Power
+ 48 Volts DC
Maximum Input Level
Line mode
+22 dBm unbalanced
+28 dBm balanced
Power Consumption
.27 Amps MaxAC @ 120 VAC
.27 Amps Max AC @ 230 VAC
Mic mode
Aux 1& 2
- 14 dBm unbalanced
+28 dBm balanced
AC Dropout Voltage
+103 VAC @ 120VAC Nominal
+203 VAC @ 23OVAC Nominal
+22 dBm unbalanced
+28 dBm balanced
Internal Mains Fuse
.25 Amps Slo-Blo 3AG
Input Impedance
4k Ohm
4k Ohm
Size (Single space standard E.I.A. Spec)
19.0” (482.6mm) Width
6.0” (152.4mm) Depth
1.75” (44.45mm) Height
Aux 2 Input Impedance
Maximum Output Level
Balanced
Shipping Weight
Unit Weight
9 lbs (4.08kg)
7 lbs (3.18kg)
+28dBm
+22dBm
Unbalanced
Output Impedance XLRs
Line mode
100 Ohms
200 Ohms
Mic mode
Output Impedance TRS
Unbalanced
60 Ohms
Balanced
120 Ohms
Rise Time
8.6uSec
>65dBm
Stereo Separation
Attenuation Of Llne/Mic
Output Switch
20dBm
Isolation Between 1/4” and >100dBm
XLR Outputs
C.M.R. (Common Mode
Rejection) of Input
> 55dBm @ 60Hz
whirlwind
· 99 Ling Road · Rochester NY 14612 · 800 733-9473
|