TOA Electronics U-13R - Unbalanced Line Input Module with High/Low Cut Filters and Mute-Receive for 900 Series (Dual RCA) - Manual (Page 31)

FREQUENTLY ASKED QUESTIONS PAGE 32
General
7 How do I use one of the 900 Series processor modules?
When using one of the processor modules such as the E-03R, E-04R, E-05R, E-06R with an A-900MK2, insert
the module in an empty module slot. Then run a cable from the pre- amp out jack located on the rear of the
A-900MK2 to the input jack of the processor module. Next run a cable from the output jack of the module to the
power amp in jack on the rear of the amp. This will route all audio signal through the processor module before it
reaches the power amp section of the unit.
When using a processor module with an M-900MK2 mixer and P-900MK2 power amp, the processor module
can be inserted in an empty slot on the M-900MK2. Connect a cable from the aux out jack on the M-900MK2 to
the input of the processor module. Then connect a cable from the output jack of the processor module to the
input of the P-900MK2 power amp.
Another way of doing this would be to insert the processor module in the module slot of the P-900MK2. Connect
a cable from the output of the mixer to the input of the processor module. Then connect a cable from the output
of the module to the screw terminal input of the P-900MK2 power amp.
8 What is the proper wiring for the screw terminal type input modules?
Pin 1: Earth. Pin 2: Common. Pin 3: Hot. When wiring an unbalanced source to a balanced input module:
Connect the source (+) output to Pin 3 Hot. Connect the source (-) or shield output to Pin 2 Common.
9 What’s the difference between the “L” Series and “B” Series modules?
“B” Series modules are balanced, line level, high impedance inputs.
“L” Series modules are balanced, line level, low impedance inputs.
Most modern audio equipment provide low impedance outputs which are designed to drive high impedance
inputs. Maximum voltage transfer occurs when the input impedance is at least ten times the source output
impedance. Almost all of the output signal voltage is transferred to the input.
Impedance matching (output impedance to input impedance) results in maximum power transfer and causes
approximately -6dB of signal voltage loss. This can often exceed a source device’s minimum output load
impedance specification. In most cases, use B Series instead of L Series modules.
10 Which modules are for “mute send”?
M-41S for microphone level input. B-41S, L-41S for balanced line level input. U-43R, U-43S for unbalanced
line level input. ML-11T for microphone or line level input (selectable). S-20S is a digital message repeater
module with mute send select-ability.
11 Which modules are for “mute receive”?
M-11S for microphone level input. B-11S for balanced line level input. L-11 for balanced or unbalanced line
level input, low impedance, line matching. ML-11T for microphone or line level input (selectable). U-11R,
U-11S, U-12S & U-13R can be used for unbalanced line level input. U-14R for unbalanced dual input priority
(Jukebox input mutes BGM input), both are muted when the mute receive jumper is set.
Troubleshooting
12 Why won't the M-11 (Microphone Input with Mute-Receive) pass signal?
The M-11 will not pass signal "out-of-the-box". Cut jumpers to select the mute response mode: Normally-Off or
Normally-On. See page 35, Jumper Settings, for more information.
13 Why won't my paging source override my music source?
First, verify that the paging source is connected to a Mute-Send module and the music source is connected to a
Mute-Receive module. Next, verify that the module jumpers are configured for Mute Bus #1 or Mute Bus #2 (or
both). Test the Mute-Receive module's mute function by placing a jumper between Mute Bus #1 (or #2) and
Ground terminals. Last, adjust the Mute-Send module's "Sensitivity" control to lower the mute activation
threshold. The Mute-Send module activates the mute function based on input signal level exceeding this
threshold.
14 Why isn't my condenser microphone working with an M Series module?
Verify that Jumper "J1" on the M Series module circuit board is intact and secure the module to the chassis
with the supplied screws.
15 Why is my signal level low with an L Series module?
Removing resistor R1 (680
Ω
) on the module's circuit board will provide approximately 6 dB additional gain by
converting the module's input impedance to 10 k
Ω
. See page 16, "Impedance Matching".
FREQUENTLY ASKED QUESTIONS
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