IVIE 802A User manual

802A Manual
Operation and Owner’s Manual for the
Model 802A
Automatic Mixer
Printed in U.S.A.
____________________________________________________________________
Ivie Technologies Inc. 1605 NW State St. Orem, UT 84043 Tel: [phone] Fax: [phone]
Email: [email protected] Website: www.ivie.com

Introduction
The Ivie 802A Automatic Microphone Mixer is flexible, powerful and innovative, yet is the most
economical and simple to install automatic mixer Ivie has ever produced. In the design and
development of the 802A, great emphasis was placed on simplicity of setup and ease of operation.
The 802A can be set up using the front and rear panel controls, or it may be set up via a computer.
Please note that a computer is NOT required at any time to either setup or operate
the mixer. Although not required, a computer can increase the mixer’s power and versatility.
Once set up, the front and rear panel controls can be “locked” using an ANK-1 Audio Net™ key,
or by using a computer loaded with Audio Net™ software connected to the 802A through an Ivie
78-232A, RS232 to RS485 converter.
Four Automatic Mic/Line Inputs
The 802A has four, automatic gating, transformer balanced inputs. These inputs are connected to a
microprocessor which determines when a specific input should be gated, or turned on. Twelve
dB of attenuation is applied to an input when it is gated off. Whenever an input is gated on, the
12dB of attenuation is removed. A standard NOM attenuation of 3dB per doubling of open
microphones is applied whenever more than one microphone is gated on at a time.
Non-automatic Inputs
The mixer has two, electronically balanced, line level, non-gating inputs. These two inputs neither
affect nor are affected by the NOM attenuator.
Internal Controls
There are only four internal controls in the mixer. Input channels 1 - 4 can be set for microphone
level or line level input sensitivity. The mixer is shipped from the factory with these switches set
to microphone level sensitivity.
To access these switches, loosen the four screws that retain the lid on the mixer and remove the lid.
The switches are located on the printed circuit board. They are labeled “CHAN 1, CHAN 2,
CHAN 3, and CHAN 4. There is a silk-screen label showing the positions for mic or line level
sensitivity.
Rear Panel Controls
Input Switches for Channels 1 - 4
PH PWR - Phantom power on/off switch. In the ON position, +15Vdc of phantom power is
applied to the input connector for the powering of condenser microphones. This switch should be

set to “ON” when using a microphone that requires phantom power. This switch should be in the
“OFF” position when used with wireless microphone receivers.
14dB PD -14dB PAD. In the “OFF” position, the 14dB pad is not in the circuit and the gain
through the input preamp is 55dB. Normally, this switch is set to the “OFF” position. Many
microphones using phantom power have an output level that is much higher than that of a dynamic
microphone. The 14dB pad switch should be set to the “ON” position when a high output level
microphone is connected to the input.
HP FILT - High Pass Filter. This filter passes only higher frequencies by cutting, or rolling off,
the lower frequencies. When the high pass filter switch is set to the “ON” position, the low
frequencies are rolled off at the rate of 6dB per octave, beginning at 125Hz. This filter helps
reduce low frequency noise generated by handling and breath popping.
AUX 1 to AUX OUT - This switch is used in conjunction with teleconferencing systems.
Setting the switch to the “ON” position prevents the audio from the AUX 1 input from being mixed
with the other inputs and sent to the AUX output (mix minus). If the output of a teleconferencing
system were connected to the AUX 1 input, it would be desirable for that signal to appear on the
main output so it could be heard in the room, but it would not be desirable to have it mixed with the
microphone inputs and sent out the AUX output to feed the teleconferencing input. This would
cause problems with feedback.
LAST ON - This controls the LAST ON feature of the mixer. Automatic mixers gate inputs on
and off depending upon sound levels at the microphones. Typically, with no sound at any
microphone input, all inputs would be gated off. The LAST ON feature allows the mixer to have
at least one microphone gated on at all times. The last microphone that was gated on will remain
on until another mic gates on to take its place.
There are several advantages to always having an open microphone in the room. When recording
the output of the mixer, the LAST ON does away with the annoying sound of the room noise being
gated on and off. It also keeps a mic gated on during pauses in a person’s speech so that there will
not be any lost syllables as the mic gates off during a pause and then back on as speech begins
again. The LAST ON feature is very important when the mixer is used in teleconferencing
applications, especially when an active echo canceller is used.
Lock LED
This LED indicates whether or not the mixer is “LOCKED.” This LED is a duplicate of the front
panel LED with the same label. When the LED is flashing, the mixer is locked; that is, its front
and rear panel controls are disabled. When it is not flashing, the mixer is not locked. When the
mixer is not locked, all front and rear panel controls ( pots, switches, etc) are operational. Any
adjustment to any of these controls affects the operation of the mixer.
Conversely, when the mixer is locked, theadjustment of any front or rear panel control has NO
effect upon the operation of the mixer. The mixer can be locked and unlocked with an ANK-1
Audio Net™key, Ivie’s special “electronic key,” or by a computer with Audio Net™ Software.
Automatic/Manual Switch
This switch selects an optional mode of operation when a remote control is connected to the 802A.

The 802A can detect when a remote control is connected to the mixer. If the Automatic/Manual
switch is set to “Automatic,” the mixer mixer will continue to automatically gate the inputs on and
off when the remote control is connected. Conversely, if the Automatic/Manual switch is set to
“Manual,” an input connected to a remote control will operate in a manual mode; that is, it will be
gated on all the time. When the remote control is disconnected, automatic operation will be resumed.
Aux Output Level
This rear panel control is adjusted with a small screwdriver. It controls the output level of the
Auxiliary output.
Rear Panel Connections
Input Connections Channels 1 - 4
These four inputs are transformer balanced and can accept either microphone or line levels. They
will also accept unbalanced input signals. A slide switch located inside the mixer sets the input for
either mic level or line level input signals. As shipped from the factory, the inputs of the 802A are
set for mic level.
Microphone Level Inputs
The four microphone inputs are designed to accept standard, balanced, low impedance microphones
(50 - 600 Ω). These inputs will work well with both dynamic and condenser microphones. If a
condenser microphone is used, the phantom power for that input may need to be turned on. Also,
condenser mics can have a higher level output than a dynamic microphone, so switching in the
14dB pad may be desirable when using a condenser mic.
Line Level Inputs
When the internal mic/line slide switch is set to line level, the input can accept line level signals.
Selecting line level on an input adds 50dB of attenuation to the front of that input. When in the line
level position, an input is transformer balanced with an input impedance of 30kΩ. The phantom
power should be turned off when an input is configured for line level.
The Two Aux Inputs, and the Main and Aux Output
Aux inputs 1 and 2 are electronically balanced, line level inputs with an input impedance of 82kΩ
balanced, and 41k Ωunbalanced. The level of Aux input 1 is controlled by the front panel, Aux
Level Control. The level of Aux input #2 is fixed at 10dB of gain. This input is designed to work
with outputs that can supply a level of 0.3Vrms (-10dBV). The maximum level connected to this
input should not exceed +10dBV.
The Main and Aux outputs are both transformer balanced outputs.

Front Panel Controls
All of the front panel controls of the mixer can be remoted. All that is required is a standard, 10kΩ
pot which is connected to the remote control terminals on the rear panel of the 802A. One 10kΩ
pot controls one channel. Ivie Technologies manufactures a complete remote control, the model
RMA-6, that can be used with the 802A, or individual remote controls can be connected to only
those channels requiring remote control. The Ivie Technologies RM-1 and RM-2 pushbutton
remote controls can also be used with the 802A.
A connection diagram for the remote controls can be found on the inside, rear cover of this manual.
Audio Net™ Terminals
The Audio Net™ terminals on the rear of an 802A Automixer are connected in parallel with the
front panel Audio Net™ connectors. Either Audio Net™ connector allows access to the mixer.
The rear panel terminals are normally used to connect the mixer to other Audio Net™ units on the
network. Linking units is a simple matter of paralleling all the rear panel Audio Net™ terminals
together. Two-conductor, shielded cable should be used. The shield of that cable should be
connected to ground on only one unit. The purpose of the shield is to shield the data line from
radiating. It is not part of the signal path.
Figure 1 below shows how several Audio Net™ units are linked:
AUDIO
NET
AUDIO
NET
AUDIO
NET
Unit #1
Unit #2
Unit #3
To other units on
the net.
Connect shield to
ground on this
end ONLY!
Do NOT connect the
shield to ground on
any other unit.
Audio Net™ terminals on
different units.
Figure 1

Ground Link Terminals
As shown in the diagram on the inside, rear cover of this manual, there are two ground terminals
on the rear of the mixer, an Audio ground and a Chassis ground. There is a link jumper
connecting these two grounds together. This is the normal configuration.
The power supply for the mixer has a 3 prong, grounded, AC power plug. The ground prong on
AC power plug should never be “lifted” or isolated from ground. Should the mixer need to be
isolated from ground, the ground link can be removed. Normally, the Audio ground terminal is
then “referenced” (connected) to another ground point somewhere in the system.
If there are multiple mixers or other Audio Net™ products in the system, a “Star ground” should
be used. A star ground will help reduce overall system noise and will also help reduce ground
loops. An example of star grounding is shown on the inside, rear cover of this manual.
DC Pwr In
Connect the supplied UL®, CSA® approved power supply to this connector. The power supply
provides ±15Vdc and +5Vdc to the mixer.
Setting Up the Mixer
The 802A is very easy to install and set up. There are no gain trim or threshold controls to be set.
The automatic mixer portion of the mixer is set by adjusting the channel level controls as would be
done for normal mixer operation. The following procedure should be used:
1. Set up each input for the configuration needed: Mic or line level, phantom power, pad in/out
etc.
2. Set all unused inputs to -∞(fully counter-clockwise).
3. Set all of the microphone channels that are being used to the +5 position on the front panel.
This is for a normal dynamic microphone (14dB pad off), or for a condenser microphone (14dB
pad on). When using microphones of the same type, the input level controls should be set to
approximately the same level. If different types of microphones are used, lower sensitivity mics
may need to have their gain increased, while higher sensitivity mics may need to have their gain
decreased.
4. With the LAST ON feature activated (set to on), speak into a microphone and adjust the Master
Output level so that it is just below the level of feedback.
5. One at a time, speak into all the other microphones and adjust their individual input controls to
the desired level.
6. Adjust Aux inputs as desired.

Specifications
Input channels 1-4: Transformer, balanced and isolated. Switchable between microphone or
line input levels. Microphone input impedance: 1200Ω. Compatible
with microphone sources of 600Ωor less. Line input impedance: 30k Ω.
Low cut filter: ---------- 6dB/octave, -3dB @ 100Hz
Noise: ------------------- (EIN 20Hz to 20kHz) -125dBV (200Ωsource)
Sensitivity: -------------- 0.4mv in for +18dBm out
Input Overload: --------- -9dBV (with 14 dB pad enabled).
Phantom power : ------- +15Vdc
Auxiliary Inputs:
Input impedance: ------- 20k Ω
Input level: -------------- -10dBV recommended
Outputs: --------------- Balanced, transformer isolated.
Output impedance: ----- 110 Ω
Recommended Load Z: 600 Ωor greater.
Output level: ------------ +18dBm
Size: --------------------- 19” W x 1 3/4” H X 8 1/4” D (48.3 cm x 4.5 cm x 21 cm)
Weight: ----------------- 10 Pounds with external power supply
Shipping Weight: ----- 13 Pounds
Index
Audio Net™ Terminals ------------------------------------------------------------------------------- page 4
Automatic/Manual Switch ---------------------------------------------------------------------------- page 3
Aux Output Level --------------------------------------------------------------------------------------page 3
DC Pwr In ----------------------------------------------------------------------------------------------page 5
Four Automatic Mic/Line Inputs ---------------------------------------------------------------------page 1
Front Panel Controls ----------------------------------------------------------------------------------page 4
Ground Link Terminals -------------------------------------------------------------------------------page 5
Input Connections Channels 1 - 4 -------------------------------------------------------------------page 3
Input Switches for Channels 1-4 (Phantom Power, 14dB Pad, High Pass
Filter, Aux 1 to Aux Out, Last On) --------------------pages 1 & 2
Internal Controls ---------------------------------------------------------------------------------------page 1
Introduction -------------------------------------------------------------------------------------------- page 1
Line Level Inputs --------------------------------------------------------------------------------------page 3
Lock LED -----------------------------------------------------------------------------------------------page 2
Microphone Level Inputs -----------------------------------------------------------------------------page 3
Non-automatic Inputs ---------------------------------------------------------------------------------page 1
Rear Panel Connections ------------------------------------------------------------------------------ page 3
Rear Panel Controls -----------------------------------------------------------------------------------page 1
Setting Up the Mixer ----------------------------------------------------------------------------------page 5
Specifications ------------------------------------------------------------------------------------------ page 6
The Two Aux Inputs, and the Main and Aux Output --------------------------------------------- page 3

DC PWR
IN AUDIO
Gnd Chassis
Gnd
Ground
Link
See Manual
Ground
Link
See Manual
Ground
Link
See Manual
AUDIO
Gnd Chassis
Gnd
AUDIO
Gnd Chassis
Gnd
To other Audio
Net™ units
Recommended "star" ground wiring: Keep
ground link on 1st unit. Remove links from
all other units. Use large gauge wire and
home runs.
Ivie Technologies 802A Automatic Mixer
INPUT CH.1INPUT CH.2INPUT CH.3 INPUT CH.4
AUDIO
NET MAIN
OUT AUX
OUT AUX 2 IN AUX 1 IN
AUX OUTPUT
LEVEL
0
-∞20
COMMON
+RMT
CH1
CH4
CH2
AUX
CH3
MSTR
REMOTE CONTROL
LOCK
OFF
ON- AUX1 TO
AUX OUT
OFF MAN
ON- LAST ON
AUTOMATIC
All remotes
are 10,000
ohm linear
taper pots
Loud
Soft
+ RMT
Common
MASTER
CHANNEL 3
CHANNEL 2
CHANNEL 1
CHANNEL 4
AUDIO
NET
AUDIO
NET
"LOCK" LED
flashes when
the mixer has
been locked. All
front and rear
panel controls
are disabled
when this LED is
flashing
Sets the
level of the
Auxilliary
output
12 34
PH PWR - ON
14DB PD - IN
HP FLT - IN
OUT OUT OFF OUT OUT OFF