Specifications

LineIMic, Aux, and Phones outputs approach clipping. If
this light flashes on, turn down the Microphone Channel
controls of the channels in use or turn down the
Master control until the light stays out.
1 3. Aux Input: A l/4 -inch unbalanced phone jack input on
both the front and rear panel of the AMS mixer,
suitable for Aux level and line level sources, such as
tape recorders or players or conventional
mrxers. This
non-gated input is mixed with the combined microphone
signals to appear at the
LineIMic, Aux, and Phones out-
puts.
14. Aux Control: The position of this control deter-
mines the level of the Aux Input.
15. Master Control: The position of this control deter-
mines the level of the combined microphone and aux
signals at the
LineIMic, Aux, and Phones outputs.
16.
LineIMic Output: This male XLR audio connector
has switch-selectable levels: either low-impedance
balanced microphone level or 600-ohm balanced line
level. This output provides the combined gated
microphone and non-gated aux input signals.
17.
Aux Output: The '/4-inch phone jack outputs on the
front and back panels are intended for unbalanced Aux
or line level loads. This output also provides the combin-
ed gated microphone and non-gated aux input signals.
18.
Phones Output: This %-inch phone jack is suitable
for most stereo or mono headphones with
2- or
3-circuit phone plugs. The signal at this output is iden-
tical to that at the
LineIMic output.
19. Logic Terminals: These four screw terminals are
built into a female barrier block module that plugs into
a male connector on the rear panel below the Direct
Output jacks (Figure
31. The barrier block's plug-in
design ensures proper placement and simplifies ter-
minal wiring by eliminating the need for soldering. Con-
nections to these terminals are not necessary for basic
AMS operation, but allow the AMS mixer to perform
additional functions. Unshielded wire or
multi-conduc-
tor cable is adequate for the connectors.
The logic levels are
nomtnally 0 volts [low] and 5.0 volts
[htgh]; they are directly compatible with standard
5-volt logic families [including CMOS and
TTL].
GATE OUT: This terminal follows the channel gating
and goes to logic "low'' when the
mrcrophone is gated
on. Sufficient current-sinking capability is provided to
l~ght externally powered LED'S [see Logic Functions
sectlon for example].
LOGIC GROUND:
The Logic Ground terminals of all
channels are connected together internally and are
dist~nct from the AMS aud~o ground. All logic ground
connections should be made to these terminals. The
power supply ground of external logic circuitry should
be connected to the
L.ogic Ground terminal of Channel
8 [or Channel 4 In 4-channel AMS mixers]. To avoid
sw~tch~ng clicks, do not Interconnect the Log~c Ground
with the audio,
chassrs, or rack grounds.
MUTE IN: Applying a logic "low" to this terminal
[from a logic gate or a switch closure to Logic Ground]
gates the channel off. The channel output drops to the
level set by the Off-Attenuation switch. The Mute func-
tion dominates Override when both are simultaneously
activated unless a jumper change is made so that
Overr~de dominates [see Internal Modification section
for details].
OVERRIDE IN:
Applying a logic "low" to this terminal
[from a logic gate or a switch closure to ground] forces
the channei on. The mixer is supplied so that when both
Mute [described above] and Override of a channel are
activated, Mute dominates.
lnhibit Function: The Mute function can be altered
to
lnh~bit by an internal jumper change for each
channel [see Internal Modifications section for
details]. After the change, a logic "low" at the Mute
In terminal prevents the channel from gating on if it
is off, but allows it to remain on if it is already on.
After the Inhibit modification, for certain specialized
applications a logic connection can be made between
a channel's Gate Out and its Mute In terminal.
IMPORTANT: To prevent high-frequency oscrlla-
tion, never connect a channel's Gate Out to its
Mute In unless the lnhibit modification has been
made.
LOGIC GND
MUTE IN
AMS MIC IN
3
REAR-PANEL CHANNEL PLATE
FIGURE
3
20. Link Jacks: These rear-panel %-inch phone jacks
are used to link up to
25 AMS mixers together to pro-
vide an input capability of as many as
200
microphones. To link mixers, use short I -conductor
sh~elded cables with -inch phone plugs on both ends.
Plug a cable between the Link A Out jack of one mixer
and the Link A In jack of the next mixer;
AND plug a
cable between the
L~nk B Out jack of one mixer and the
Link B In jack of the next. Leave open the Link In jacks of
the first
mlxer in the chain and the Link Out jacks of the
last mixer
In the chain. Both the Link A and Link B jacks
of each mixer must be connected: A Outs to A Ins
and
q Outs to B Ins. Use the Link jacks for l~nking only,
not for audio inputs or outputs.
IMPORTANT: When uslng the logic term~nals on