AlphaMix
Portable Audio Mixer
Operation Manual for Mixers with PCB V1.1
Copyright 2003
Professional Sound Corporation
Printed in the U.S.A.

TABLE OF CONTENTSDESCRIPTION……………………………………………………………………………4
SAFETY WARNINGS……………………………………………………………………4
APPLICATIONS…………………………………………………………………………..4
FUNCTIONSINPUTS……………………………………………………………………………5-7
A.

BALANCED INPUTSB.

INPUT LEVELSC.

MICROPHONE POWERINGD.

LOW CUT FILTERE.

CHANNEL GAINF.

CHANNEL PANSG.

CHANNEL METERINGH.

BOOM POLE REMOTE CONTROLOUTPUTS…………………………………………………………………………8-9
A.

BALANCED OUTPUTS

B.

MULTIPIN (BETA) CONNECTORC.

OUTPUT LIMITERSD.

TRANSCRIPTION OUTPUTSE.

HEADPHONE OUTPUTSF.

TAPE RETURNSG.

WIRELESS MIC POWER DISTRIBUTION

METERS…………………………………………………………………………….9
A.

PEAK READING METERS

2

ADDITIONAL FEATURES…………………………………………………………10A.

SLATE MICROPHONEB.

REFERENCE OSCILATORC.

BATTERY TESTD.

M-S AND X-Y STEREO RECORDING

POWERING………………………………………………………………………….11
A.

INTERNAL POWER, NP-1 BATTERYB.

INTERNAL POWER, ALKYLINE BATTERIESC.

EXTERNAL POWERCONSTRUCTION……………………………………………………………………12
A.

CHASSISB.

ELECTRONIC TOPOLOGYC.

ENVIRONMENTAL OPERATIOND.

PORTA BRACE CASE

INTERFACING………………………………………………………………………13
A.

TO BETACAMSB.

TO RDAT RECORDERSC.

TO WIRELESS MICROPHONESWARRANTY AND NON-WARRANTY SERVICE…………………………………15
CONNECTOR PIN ASSIGNMENTS……………………………………………15-16
SPECIFICATIONS…………………………………………………………………….17
CE DECLARATION OF CONFORMITY……………………………………………18

3

DESCRIPTION
Thank you for purchasing the Professional Sound Corporation AlphaMix Portable
Audio Mixer. PSC is confident that this new AlphaMix mixer has set new
standards for portable mixer technologies and features. Please feel free tocontact us if you have any comments or questions concerning your new mixer.
Additionally, we invite you to share your suggestions for new products you would
like to see developed.
Professional Sound Corporation extends a one-year warranty on parts and labor
to all AlphaMix owners who return their warranty cards at the time of purchase.
This warranty gives you specific rights, which are stated on the card, and enables
us to keep you informed of product updates.
The PSC AlphaMix provides all the functions necessary to produce studio quality
recordings in the field. It’s user friendly features, rugged design and sonic purity
make the AlphaMix perfect for electronic news gathering (ENG) electronic field
production (EFP) and feature film production. There’s only one AlphaMix and it’sfrom PSC.
HEARING SAFETY WARNINGS:
Please be sure that you have read this entire manual before operating thismixer.
While special attention has been given to your safety and hearing
protection, the operator determines proper and safe operating levels.
Please note the following:
Always turn down the headphone volume before plugging in yourheadphones.
Always operate your headphones at the lowest practical level.
Be especially cautious in unknown or widely varying environments.
Remember, your ears are your livelihood. Turn it down!
APPLICATIONS
•
•
•
•
•

Electronic News Gathering
Location recording (Dialogue and Music)
Digital Recording and Playback
Broadcast remotes
Desktop Mixing for Video Post Production

4

INPUTS:A.

BALANCED INPUTSThe PSC AlphaMix Audio Mixer provides four input channels utilizing female XLR
connectors. The ultra low noise input circuitry has been developed to set new
standards in low noise field production gear. The XLR connectors are wired asfollows: Pin 1 shield (ground), Pin 2 Audio high (in phase), Pin 3 Audio low (out ofphase). Balanced wiring enables longer cable runs without the worry ofexcessive noise due to nearby electromagnetic and radio frequency interference.
These balanced inputs may be unbalanced if desired. Either pin 2 or 3 may betied to ground (pin 1) to unbalance the inputs of the AlphaMix. Note: The AES
standard for unbalancing an XLR connector is to tie pin 3 to ground (pin 1).
B.

INPUT LEVELSThe PSC AlphaMix can accommodate a wide range in input levels. Microphonelevels of all types can be handled as well as line level signals. The input range of
the AlphaMix is –70dBu to +4dBu. Thus the AlphaMix is compatible with allforms of consumer and professional audio equipment. The input level switches
are located below and to the right of each input XLR connector. These input
level switches provide for two level settings: “M” Microphone (0dB attenuation),“L” Line (50dB attenuation). In addition to the line/mic switch, each input channelof the AlphaMix is equipped with a rotary trim pot that allows the user to set
precise pre-amplifier gain. These input gain trims have a range of approximately
40dB. The combination of these two input level controls can be used to correctlyinterface sources of varying levels to the AlphaMix’s preamplifiers. Correct level
matching ensures maximum headroom and lowest possible noise floor.
C.

MICROPHONE POWERINGThe AlphaMix can accommodate the most popular microphones used today.
The microphone powering switches are located directly below the input XLR
connectors. They can be switched to either: Dynamic (D), Tornader (T) or
48Phantom (48).
In the Dynamic position the mixer provides no microphone powering. This
position is used with dynamic microphones, line level inputs and when using
wireless receivers.
In the T Position the mixer provides 12 volts DC to power 12T microphones. This
12T microphone power standard is also known as AB power. 12T microphone
power supplies 12 volts dc across pins 2 and 3. Pin 2 is positive with respect topin 3. Pin 1 is ground. 12T microphone power should only be used withmicrophones designed to operate on 12T. Do not use it with microphones
designed for 48PH or 12PH.
In the 48 Phantom Position the mixer provides 48 volts DC to power 48PH
microphones or simplex powered microphones with a range of 9 to 52 volts or 125

to 52 volts. Pin 1 is shield to ground while pins 2 and 3 carry 48 volts DC. The
term “phantom” is derived from the fact that there is no voltage potential
developed across a dynamic microphone transducer that would interfere with its
operation. However, most portable wireless receivers will not operate with 48PH
turned on. We strongly recommend setting inputs to “dynamic”0 for use with all
wireless systems.
D.

LOW CUT FILTERS

Each input channel of the AlphaMix is equipped with an active low cut (highpass) filter. These filters are activated via the three way switches located below
the adjacent channel fader knobs. These filters will attenuate all frequencies
below a preset frequency at a rate of 12dB per octave. When set at “20Hz”,
frequencies below 20 Hz are effectively rolled off with the mixer operating at full
frequency response. Optional low cut filter settings of 80Hz and 140Hz will roll
off the frequencies below these figures at a rate of 12dB per octave (-3dB level at
80Hz and 140Hz respectively. Low cut filtering is important in location recording
where wind noise can cause pre-amplifier overload. Switching the low cut filter
setting to either the 80Hz or 140Hz cutoff setting can minimize this effect. The
low cut filter switches are located on the front of the AlphaMix.
E.

CHANNEL GAIN

In order to limit noise and increase headroom, the channel fader controls arelocated in the feedback path of the channel amplifiers.
This provides
continuously variable gain rather than just a decrease in channel output level
when an overload situation occurs. This results in increased headroom andlower chance of signal clipping (severe distortion). The AlphaMix uses sealed,
conductive plastic Clarostat tm pots for channel faders. In addition the gain of
the first pre-amp is continuously variable over a 40Db range. This gain trim pot islocated on the front panel of the mixer and is retractable so it is out of the way
when not being used.
F.

CHANNEL PANS

The new AlphaMix contains front panel mounted pan pots. These pan pots areused to route the individual input channel’s signal to either the left or rightsumming buss. These pots are equipped with center detents allowing the pots toremain centered when the operator so desires. These pots are also equippedwith a retracting mechanism that allows the pots to be pushed in flush with thefront panel after they have been set to the operators desired setting. This helps
keeps the front panel “clean” and uncluttered and reduces the chance of theoperator accidentally bumping the pan pot setting.
H.

CHANNEL METERING

Each input channel on the PSC AlphaMix is equipped with a basic three LED
meter. This meter indicates pre-fader audio level thus it is active even when thechannel fader is turned down. By making this meter pre-fader, you can presetchannel gain levels before opening up the fader. The three LED’s are coloredgreen, yellow and red. These LEDs are calibrated to represent specific audio

6levels. The bottom most LED (Green LED) is activated when the pre-fader audio
level reaches –20dB relative to nominal Zero level. The middle LED (Yellow
LED) is activated when the pre-fader signal level reaches –6dB. The top LED(Red LED) is activated when the pre-fader signal level reaches 0dB. For proper
signal level setting, you should adjust the retractable gain trim pot so that the
Red LED is just lighting on the peaks of signal. It should not be lit on
continuously. For example: If you are recording dialog from an interview you
would want to set the gain trim pot so that the Green LED is on whenever theinterviewee is speaking and the Yellow LED is on about half the time. The Red
LED should only light occasionally.
These LED meters are also useful when sending audio out of the individual line
outputs that are located directly above the XLR inputs. These balanced outputs
have a nominal signal level of 0dBV and are wired as pre-fader so they are activeat all times. The above mentioned audio levels are equivalent of what you willfind on the individual line outputs.
I.

BOOM POLE REMOTE CONTROLThe AlphaMix offers the ability to remotely control the audio level of the channel
one input. This feature allows the operator to boom with two hands rather thanholding the boom pole with one and riding levels with the other. To use thisfeature you must first set up the mixer as normal (appropriate microphone power
turned on, channel fader turned off for the moment). Strap the boom pole remotecontrol to your boom pole, and plug the boom remote connector into the “remote”
control connector located on the left side of the mixer directly above the number
one input XLR. Set the slide fader on the remote control to it’s mid position andre-open the channel fader upward (clockwise) until a normal signal level isindicated on the meters. You are now free to ride gain using the remote control.
Sliding the knob toward the cable end of the remote control lowers the volume,
sliding the knob away from the cable end of the remote raises the volume.
Please note that the use of the remote control overrides the channel gain
trim pot while the remote is in use. Whenever the boom remote is plugged
in, a front panel mounted LED will indicate its use. To remove the boom poleremote control, you must simply press the release button on the connector andpull on it. *Safety Note* You must always turn down the channel fader
before removing the remote control! High audio levels may occur if thechannel fader is in the maximum or near maximum setting when the boom
pole remote control is unplugged. You should note that the boom pole remoteallows an approximate control range of 25 dB. This allows you complete working
control over audio levels from the boom pole.
OUTPUTS:A.

BALANCED OUTPUTSThe AlphaMix contains very high quality custom-made dual isolated audio output
transformers.
These transformers have been designed to provide wide
bandwidth, low distortion and real-world ease of use. These dual output
transformers allow you to feed two cameras without interference. Dual outputs
require twice the transformer size, weight and cost. Other manufacturers have7

cut corners and wind their transformers on standard single output size cores.
Ours were custom made to our specifications by a leading transformer
manufacturer. Transformers have been chosen over a transformerless design
because of their inherent ability to interface with virtually any other device,especially RF based products. This is very important in this day and age inconsideration of the frequent use of multiple RF transmitters. These outputs areavailable via the right hand panel mounted male XLR connectors. These outputs
are switchable between line or microphone levels. At the line level setting, themixer outputs deliver a nominal +0dBv signal into 10K Ohm loads. When set tomicrophone level, the outputs supply –50dBv signal levels. Please note that 10K
Ohm loads are typical of the loads imposed on the mixer by most Betacams, andother recording devices. Additionally, the AlphaMix’s outputs are capable ofdriving 600-Ohm loads.
B.

MULTI-PIN (BETACAM) CONNECTOR

The AlphaMix is equipped with two multi-pin in/out connectors designed primarily
to interface with Betacams. These connectors provide left and right balanced
outputs as well as left and right tape returns used for confidence monitoring. The
two connectors are labeled Camera A and Camera B. The Camera A connector
is wired in parallel to the standard XLRs. These multi-pin connections provide aconvenient means of interfacing the AlphaMix to two Betacams. Professional
Sound Corporation manufacturers a complete line of Betasnake cables used asumbilical cables between mixer and camera. These cables are offered in 15’ (4.5
meters) and 25’ (8 meters) lengths and with and without camera fan out
breakaways (quick disconnects).
C.

OUTPUT LIMITERS

The limit threshold (activation level) is factory set at +3 on the meter. The limiters
compress the signal at approximately 2.7 to 1 ratio. This is to say an increase of
2.7dB in input signal will result in only a 1dB increase in output signal. Output
channel limiting is displayed on the LCD meter.
The AlphaMix contains two separate limiters that are controlled by one front
panel mounted switch. This switch has three settings: Off, Separate (S), andGanged (G). In the off position, no limiting occurs.
In the separate position, the limiters act independently of each other. This isespecially useful when recording split tracks. I.E. interviewer and interviewee on
separate channels. Thus, if one person un-expectantly raises their voice, that
limiter will activate, but the other will not. In the ganged mode, both limiters aretied together and can be triggered by either input. This is useful in recording
stereo, as independent limiting would alter the stereo image. PRACTICAL USE
NOTE: IT IS HIGHLY RECOMMENDED THAT THE LIMITERS BE USED AT
ALL TIMES WHEN RECORDING TO BETACAM TYPE CAMERAS. Most video
cameras have limited audio track headroom and can easily be overloaded
resulting in distortion of the recorded audio. Play it safe, use the limiters!

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D.

TRANSCRIPTION OUTPUTS (AUX OUTPUTS)

The AlphaMix also contains two outputs used to feed transcription recorders,wireless feeds, etc. These connectors are located directly above the main XLR
outputs. They are 3.5mm Stereo connectors wired as follows: Tip = Left, Ring is
Right, Sleeve = Ground. The output signal level is switch-able line or
microphone level (-10dBv, -50dBv). This allows these outputs to be used with
virtually all external equipment.
E.

HEADPHONE OUTPUT

The Headphone output is located on the left side panel of the mixer. The
AlphaMix’s headphone amplifier circuitry is designed to drive virtually any
headphone with an impedance rating of 32 to 600 Ohms. The headphone
circuitry is controlled by the use of two switches and a convienient front panel
mounted volume control. The two switches are used to control what the operator
listens to. The most commonly used switch is a rotary switch located on the front
panel and is used to allow the operator to choose between monitoring left to both
ears, normal stereo, right channel to both ears, mono or MS decoding.
(L,S,R,M,MS) This feature is an improvement over previous M4 designs. The
AlphaMix also contains tape returns allowing monitoring from two cameras.
*SAFETY NOTE* ALWAYS TURN DOWN THE HEADPHONE VOLUMEBEFORE PLUGGING IN YOUR HEADPHONES.
F.

TAPE RETURNSThe AlphaMix is equipped with two tape returns used to monitor tape confidence
heads from any two recording devices such as Betacams. These tape monitor
amplifiers can be adjusted to match the signal levels of most any device. Theselevels are adjusted using a small jewelers screwdriver (or “Greenie” screwdriver).
The adjustment points are located on the bottom panel of the AlphaMix. The
tape/direct switch is located on the upper right hand corner of the front panel.
When set to ”D” (Direct) the phone amplifiers to monitor the mixers output signal.
If switched to “Camera A” (Tape), then the phone amplifies monitor the externalsource such as the Betacam that is connected to the multi-pin labeled Camera A.
When set to “Camera B” the headphones monitor the Betacam connected to themulti-pin labeled “Camera B”
METERS:A.

PEAK READING METERS

The AlphaMix is equipped with a custom made LCD meter. We designed thismeter to be easy to read and camera emulating. Because the most common useof this type of mixer is with Betacams, we designed the AlphaMix’s meters toemulate the peak reading attributes found on many Betacams. In this manner,
you can be confident of your recording levels even when the Betacam is being
fed via Betasnake cable or wireless transmission. The LCD meter also displays
Left and Right Limiter functions as well as Low Battery Warning. When the “Lo9

Bat” indicator comes on, you have approximately 15 to 30 minutes of battery life
remaining.
The AlphaMix is equipped with meter lamps used for night viewing of the meters.
The light source for this meter back lighting is provided by a 18,000mc (18candela) high performance “green” LED in conjunction with a specially madewoven fiber optic light transmission panel. These two new technologies werechosen as they provide good quality back lighting without adding noise to themixer as some electro-luminescent systems do. The use of the meter backlighting adds approximately 40mA of power consumption to the mixer.
ADDITIONAL FEATURES:A.

SLATE MICROPHONE

The AlphaMix is equipped with a slate microphone. This microphone is activatedwhen the front panel “slate” momentary push button switch is pressed. The slate
microphone allows the operator to put voice slates (notes) on tape for later
reference. These are normally notes for editing tape. A level adjustment trim pot
is located on the bottom panel of the AlphaMix. *Note* When the slate
microphone is activated, the input channels are automatically muted.
B.

REFERENCE OSCILLATORThe AlphaMix is equipped with a reference oscillator used for setting of levels
between the mixer and recorder. This known reference level is also used whentransferring tape during editing. The AlphaMix’s oscillator operates at 440Hz at“0” on the meters. When setting up typical Betacams with LCD bar graph meters
you simply adjust the Betacams inputs until “0” is reached. From that point on,
you can monitor levels from the mixer only. We have chosen 440Hz simply
because it is much more pleasant in your headphones than the typical 1Khz usedby other manufacturers. We have used 440 Hz on our mixers for many years.
The reference oscillator is equipped with a level adjustment trim pot located on
the bottom panel of the AlphaMix. This adjustment is factory calibrated andshould not be adjusted without proper measurement equipment.
C.

BATTERY TESTIn addition to the low battery indicator on the LCD meter, the AlphaMix isequipped with a push button activated battery test function: When this “Batt Test”
button is pressed the remaining battery life is displayed on the top (left meter). A
full battery will indicate approximately “0” on the meter. A dead battery will notindicate on the meter. You can read the meter as a “fuel gauge”. Full bar = fullbattery, half bar = half battery, etc. This battery level meter can be adjusted forthe differences in NP-1 battery voltages. This battery test function can be
adjusted to specific NP-1 type batteries via a bottom panel mounted rotaryswitch.

10

D.

M-S AND X-Y STEREO RECORDING

The PSC AlphaMix can be used to make stereo recordings in both the mid-side
and X-Y stereo techniques. The AlphaMix is equipped with an input channelganging switch designed to allow the ganging of input channels 3 and 4. This
switch is located on the bottom panel of the mixer. When switched to the“ganged” position, both input channels 3 and 4 are controlled by pot 4. All
microphone powering and attenuation settings remain independent. X-Y stereo
recordings are accomplished by plugging in two identical microphones intochannels 3 and 4. The channel 3 pan pot is set to the extreme left and thechannel 4 pan pot is set to the extreme right. The headphone monitor modeswitch is set to “stereo”.
If M-S stereo recordings are desired, the “M” or middle microphone (cardiod
pattern) is plugged into channel 3. The “S” or side microphone (Figure 8 pattern)is plugged into channel 4. As with the X-Y setup, pan pot 3 is panned to theextreme left and pan pot 4 to the extreme right. In this case, the headphonemode switch is set to “MS”. In the MS mode, the headphone amplifiers are fed
MS decoded signals. The left headphone amp is fed M-S signals and the rightheadphone is fed M+S signals. In this manner, MS signals appear as standard
stereo signals for headphone monitoring purposes. Note that the MS decode
function only affects the headphone feeds, not the main XLR outputs.
More complete descriptions of the M-S and X-Y stereo recording techniques canbe found in the literature of the major microphone manufacturers such as
Neuman, Sennheiser, and Scheops.
POWERING:
A. INTERNAL POWER, NP-1 BATTERY
PSC is the only company to offer compact ENG mixer to offer the ability to be
powered from an internal NP-1 rechargeable battery. This feature provides aconvenient way of powering the mixer without added size, adapters or cables. In
addition, because the NP-1 battery is securely housed within the mixer, there islittle chance that the battery could be knocked loose as with conventional battery
adapters.
There are several high capacity NP-1 batteries now on the market. These
include the standard Ni-Cad, Nickel Metal Hydride and most recently Lithium-Ion.
Most of these batteries are available in both 12, 13.2 and 14.4 Volt varieties.
Either voltage will work in your AlphaMix.
The AlphaMix consumes
approximately 210mA of current when no microphones are being powered. Thistranslates into a battery life of 10 to 15 hours depending on the battery type.
Powering wireless will shorten battery life considerably depending upon wirelessmodels selected. The NP-1 battery pack is held in place with a simple spring
steel latch. To remove the battery simply push down on the latch and pull out thebattery. If you have not yet chosen a battery chemistry, and voltage, you should
know that the longest possible run time will come from batteries with the highest
amp/hour rating. Thus is you have a choice between a 13.2Volt battery at 3.9
amp/hour and a 14.4V battery at 2.5amp/hour, chose the 3.9 amp/hour battery.
11

Additional voltage does not extend run time and is of no benefit for most wirelessreceivers.
B. INTERNAL POWER, ALKALINE BATTERIES
Ten “AA” alkaline batteries can also power the AlphaMix. These batteries arehoused in a convenient battery tray designed to be inserted in the standard NP-1
battery slot. When using alkaline batteries, you can expect 4 to 7 hours ofoperation under normal circumstances. It is not recommended that thealkaline battery tray be used when trying to power wireless receivers. They
simply cannot deliver enough power to operate the mixer and wirelesssimultaneously.
Note: Never store your AlphaMix for extended periods of time with alkaline
batteries installed in the mixer. There is a possibility that the batteries mayleak causing corrosion damage of the mixer. Battery leakage and theresulting corrosion damage are not covered under the AlphaMix warranty.
C. EXTERNAL POWER
The PSC AlphaMix can also be externally powered from any source of DC powerfrom 10 to 18 Vdc. The mixer consumes approximately 210 mA of current overthis voltage range. This current consumption is nearly constant and does notvary dramatically over operating voltages like other mixers. The external power
connector is located on the right side of the mixer below the NP-1 battery slot.
Pin outs of this Hirose 4 pin connector are as follows:
Pin 4 (+) Positive
Pin 1 (-) Negative
This external DC input is protected from reverse polarity. If you in-advetantly
connect external power of the incorrect polarity, the mixer will not be damaged, it
simply will not power up.
CONSTRUCTIONA.

CHASSISThe new AlphaMix chassis has been designed for maximum torsional rigidity.
This increased rigidity provides a stable base for the mixers modern electronics.
The complete chassis is formed from 0.040” and 0.050” aircraft aluminum. All
punching is done on a computer controlled “Strippet” rotary turret punch press for
extreme accuracy. In addition, through careful design, we have managed tokeep the overall weight of the AlphaMix to 4.25 lbs. (1.9Kg) total.
The mixers sheet metal is hand-formed using various press brake setups before
the all stainless steel threaded inserts are pressed permanently into place. The
housing parts are then Chem Film TM plated for superior corrosion resistance
before being electro-statically coated with an epoxy powder coating. This
powder coat paint is then baked on in an oven. Powder coating is chosen for its
durability and environmental friendly characteristics.

12

All silk-screening is printed sub-surface (below) a hardface Lexan tm overlay.
This process provides a silk-screened label that is virtually wear proof. The
lettering will not wear off as on other mixers.
B.

ELECTRONIC TOPOLOGYThe new AlphaMix was designed from a clean sheet of paper. It utilizes
completely new circuitry designs based upon the latest advances in semi
conductor technology. In addition, it features surface mount technology for
reduced size and weight.
The AlphaMix uses proprietary preamplifier designs that are the result of many
hours spent testing and tweaking the input circuitry. We believe you will findthem to be very, very quiet. The AlphaMix uses the highest quality dual isolated
output transformers available on an ENG style mixer.
We had thesetransformers designed to our specifications and custom built with you, ourcustomers in mind. The transformer manufacturer refers to our design as the“Cadillac” of transformer designs. Transformer topology was chosen for its
inherent ability to reject RF, thus making this new mixer perfect for use withmultiple RF systems.
This new design uses modern semi-conductors from Maxim, Linear Technology
National Semiconductor and Analog Devices to name but a few. These
operational amplifiers, voltage regulators and precision voltage referencesfeature low power consumption, low noise and low distortion. They also feature
the ability to swing from rail to rail resulting in an energy efficient design.
C.

ENVIRONMENTAL OPERATIONYour new AlphaMix has been designed to operate under extreme field
conditions. The electronics have been designed to operate over a temperature
range of -4 to 158 degrees Fahrenheit (-20 to +70C) less the affects on batteries.
This in addition to the AlphaMix’s ability to operate under high humidity
conditions makes it perfect for harsh field conditions.
D.

PORTA BRACE CASE

Each PSC AlphaMix is supplied with a custom-made Porta Brace case andshoulder strap. This case includes sewn on mounting rings allowing you tomount Porta Brace accessory cases such as their RF Multi case. These cases
accommodate your wireless receivers. You can call Porta Brace or any of theirauthorized dealers for the complete line of Porta Brace products.
INTERFACINGA.

TO BETACAMS:

The PSC AlphaMix is especially designed for easy interfacing with all popular
Betacam type cameras. The AlphaMix is equipped with two 10 pin Hirose tm
connectors on the right-hand side panel. These all-inclusive connectors provide
both left and right balanced outputs and tape returns. Pin Outs are as follows:13

Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 6
Pin 7
Pin 8
Pin 9
Pin 10

Left Output High
Left Output Low
Right Output High
Right Output Low
Right Tape Return
Tape Ground
Left Tape Return
Tape Ground
GroundGroundThe “Camera A” outputs are electrically the same as the XLR outputs on the rightside of the mixer. The “Camera B” outputs are electronically isolated from the“Camera A” outputs. Both outputs can be independently switched to the mic orline levels.
PSC manufactures a selection of standard AlphaMix Beta snake cables for use
with the new AlphaMix. These cables are available in standard and camera
breakaway versions from any authorized PSC dealer. Part numbers are as
follows:
FPSC1091M4A
FPSC1091M4B
FPSC1091M4C
FPSC1091M4D
B:

15’ (4.5M)
15’ (4.5M)
25’ (7.5M)
25’ (7.5M)

Standard
Breakaway
Standard
Breakaway

TO RDAT RECORDERS:

The AlphaMix can be interfaced to virtually any professional recorder via thestandard XLR outputs. In addition, you can use the two 10 pin Hirose tm
connectors if you desire to use the tape return functions.
C:

TO WIRELESS MICROPHONES:The AlphaMix will easily accept the output signal from virtually any wirelessreceiver. It can accept microphone or line level signal via a simple switch setting.
Please note that most wireless receivers are not compatible with 48PH mic
power. You should always set the AlphaMix’s mic powering switch to “D”
dynamic when using wireless receivers.
The AlphaMix can also be used to send audio signals to Betacams via wirelesstransmitters. The use of transmitters is normally accomplished by connecting theAlphaMix’s output XLR to the audio input of the specific transmitter. Manytransmitter manufacturers supply application specific cables for this purpose.
The AlphaMix has been designed to minimize RF interference through the use of
output transformers and other RF filtering. It is important to note that transmitter
placement greatly affects transmit range and clarity.
For best results,
transmitters should be mounted away from the mixers surface allowing unimpeaded RF radiation. This can be accomplished by mounting the transmittersup and away from the mixer on the PortaBrace Strap.
14

WARRANTY AND NON-WARRANTY SERVICE
In the unlikely event your AlphaMix requires service it should be carefully packed
and shipped prepaid to:Professional Sound Corporation
Service Department
28085 Smyth Drive
Valencia, CA 91355 USA
PH 661-295-9395
FAX 661-295-8398
e-mail techsupport@professionalsound.com
Please call before shipping your mixer. We may be able to solve your problem
via the phone. Many older M4, M4A+ and M4mkII Mixers have been shipped in
to us for service with incorrect switch settings. We are always willing to help youwith your AlphaMix questions.
WARRANTY:
Complete details of the PSC AlphaMix warranty are given on the enclosed blue
warranty registration card. If you did not receive one, please contact your local
dealer or call us directly.
CONNECTOR PIN ASSIGNMENTS:
XLR INPUTS:

XLR-3-FEMALE-70 to +4dBV Nominal
PIN 1 Ground
PIN 2 Audio HighPIN 3 Audio Low

INDIVIDUAL LINE OUTPUTS:

TA3M
0dBV Nominal
PIN 1 Ground
PIN 2 Audio HighPIN 3 Audio Low

BOOM REMOTE CONTROL:

TA5M
PIN 1 Ground
PIN 2 ResistancePIN 3 ResistancePIN 4 & PIN 5 Jumped

AUXILIARY OUTPUTS:

3.5MM Stereo Female-10dBV or –50dBV Switch-able
Tip = Left
Ring = Right
Sleeve = Ground15

MONO BALANCED OUTPUT:

TA3M
0dBV Nominal
PIN 1 Ground
PIN 2 Audio HighPIN 3 Audio Low

GANGING CONNECTOR:

TA5M-10dBV Nominal
PIN 1 Ground
PIN 2 Left Audio Output
PIN 3 Right Audio Output
PIN 4 Left Audio Input**
PIN 5 Right Audio Input**** Requires 2.74K series resistor

MAIN XLR OUTPUTS:

XLR-3-MALE
0dBV Nominal
PIN 1 Ground
PIN 2 Audio HighPin 3 Audio Low

MULIT-PIN (BETASNAKE):

HIROSE 10 PIN FEMALE
PIN 1 Left Audio HighPIN 2 Left Audio Low
PIN 3 Right Audio HighPIN 4 Right Audio Low
PIN 5 Right Tape ReturnPIN 6 Tape Ground
PIN 7 Left Tape Return
PIN 8 Ground
PIN 9 Ground
PIN 10 Ground16

SPECIFICATIONS
Size:

10.125” x 6.825” x 1.900”?
(257mm x 173mm x 48mm)

Weight:4.25lbs. (1.9Kg)

Temp Range:-4 to +158F (-20 to +70C)

Batteries:

NP-1 Rechargeable, any typeor 10x AA Alkaline

Case Material:

0.040” and 0.050” (1mm and 1.25mm) Aluminum

Finish:Epoxy Powder Coat

Overlays:0.005” Hardface Lexan tm with
Sub-surface Epoxy silk screening

Global Gain:

80dB

Freq. Response:

20-20Khz +/-1dB

Signal to Noise:

130dB EIN 150 Ohms

Distortion:

00.085% THD

Low Cut Filter:

80Hz, 140Hz 12dB/Octave

Mic Power:

DYN, 48 PH, 12T to DIN Specs

Oscillator:

440Hz, automatically mutes inputs.

Slate Microphone:Electrete, variable gain. Automatically
Mutes inputs when activated.

Limiter:

1mS Attack, 100 mS Release
2.7:1 Ratio

Warranty:

1 Year, Limited

Copyright 2003, Professional Sound Corp. This manual and the complete
AlphaMix design are covered under various state, federal and international
copyright laws. No portion of this manual or any AlphaMix technologies may be
reproduced without the specific written permission of PSC. All rights reserved.
This manual and all AlphaMix specifications subject to change without notice.

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CE
DECLARATION OF CONFORMITY
EMC: This product is in compliance with the Electromagnetic Compatibility
Directive, 89/336/EEC as defined in EN 50081-1, EN55022 and EN 50082-1.
IEC801-2, IEC801-3 and IEC801-4.
LVD: This product is in compliance with the requirements of the Low Voltage
Directive, 73/23/EEC. 93/68/EEC as defined in EN60065, 1993 and/or
EN60950/A1/A2/A3: 1995
TRADE NAME:

PSC

MODEL:

AlphaMix Audio Mixer

RESPONSIBLE PARTY:

Professional Sound Corp.
28085 Smyth Drive
Valencia, CA 91355 USA

CONTACT PERSON:

Ronald Meyer(661) 295-9395

TYPE OF PRODUCT:

Audio Mixer

MANUFACTURER:

Professional Sound Corp.
28085 Smyth Drive
Valencia, CA 91355 USA

We hereby declare that the equipment bearing the trade name and model number
listed above has been tested in accordance with the requirements contained in theabove listed directives. All necessary steps have been taken and are in force toassure that production units manufactured will conform to Directive guidelines.
Professional Sound Corporation
November 2002

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