Output Panel Connectors
1.Strap Slot
Attachment point for camera straps.
2.Tape Return Input Connector
231
3.5 mm (/8 in.) TRS stereo (unbalanced) input for head-
phone monitoring of external audio sources.
1
4Tip = left, ring = right, sleeve = ground.
3.Left and Right Line Level Outputs
Active-balanced XLR line-level outputs. +22 dBu peak out-
TAPE RTNput level. Pin 2 = hot, pin 3 = cold, pin 1 = ground. Pin 3
can be grounded or ungrounded to drive unbalanced inputs.
5
1(L)2(R)5?14 VDC4.Battery Compartment
LINE OUTPUTS?+Houses two AA batteries. Insert positive (+) end of batteries
first.
Figure 3. Side Output Panel
5.External DC Power Input
Accepts 5?14 VDC from an AC to DC transformer or a bat-
tery supply. Locking, threaded coaxial connector.
Center pin = positive, sleeve = negative. Use the supplied
threaded connector for power supplies with plug-type con-
nectors (such as the Shure PS20). See Figure 5 for wiring
diagram.
Operational Notes
Input TransformersPhantom Power
The FP24 uses premium Lundahl input transformers with pre-Use one of the two phantom power settings on the FP24 for mi-
mium magnetic core material to achieve high signal-handling capa-crophones that require it. Some microphones need the 48-Volt set-
bility, flat frequency response and minimum distortion. Becauseting to avoid a loss of headroom and increased distortion. The
these transformers provide galvanic isolation from the driving15-Volt setting, however, lengthens battery life, and electret-con-
source, they offer superior isolation from the adverse and uncon-denser microphones rated for operation at 15 V or less generally
trolled environments of field-production. Their high common-modereceive no performance benefit from the 48-Volt setting. Consult
impedance also provides exceptional common-mode rejection.your microphone documentation for phantom power requirements.
Dynamic microphones not require phantom powerdo . A properly
Output Circuitry and Tape Output
connected balanced, dynamic microphone is not affected by the
Each line level XLR output of the FP24 uses a discrete, six-tran-
presence of phantom power and does not draw any current. How-
sistor, aimpedance balancedo output stage. The circuit uses over-
ever, poorly or incorrectly wired microphone cable can cause audi-
sized, high speed transistors to achieve low distortion, robust line
ble artifacts in the microphone signal (phantom power can be an
driving capability. Pin 2 is driven with signal, and pin 3 is not. (A
excellent cable tester). It is good practice to turn phantom power off
common misunderstanding is that a abalancedo output refers to
when not needed.
equaland opposite signals on pins 2 and 3. Correctly , a impedance
balancedo refers to equal impedances from pins 2 and 3 to ground,High Pass Filter
not equal signal voltages.) To drive unbalanced inputs, pin can be3
To remove excess low-frequency energy in the audio signal, use
grounded or left unconnected. There is no change in signal level
either of the two high pass (low cut) filter settings on the FP24. Use
driving balanced or unbalanced inputs.
the 80 Hz position for most applications, such as recording speech,
The FP24's tape output feeds consumer-level devices, such asmusic, and ambient sound. The 160 Hz position is useful for en-
computer sound cards, DAT or MiniDisc recorders, and cassettehancing speech clarity and reducing wind-noise. The high pass fil-
11
recorders. A cable wired with 3.5 mm (/8 in.) TRS to 3.5 mm (/8ter is a single pole design, 6 dB per octave.
1
in.) TRS or 3.5 mm (/8 in.) TRS to Left/Right phono (RCA) connec-
When possible, equalize at the sound source by microphone
tors will connect the FP24 to such devices.
selection, placement, use of a windscreen, and onboard micro-
phone filtering. Using both the high pass filter on the FP24 and the
Using the FP24 as a Mixer
one on a microphone has an additive effect, increasing the overall
The FP24 can be used as a simple two-channel mixer. Possible
slope of the roll-off.
applications include:
w Quickly reversing the stereo image of a recording withoutHeadphone Monitoring and Tape Return
reconnecting inputs or outputs.The three position Tape Return switch on the front panel selects
the audio source being monitored:
w During set up, checking for mono compatibility by assigning
both inputs to the same output.Center Position�Program audio (normal operation). Monitors
the Left and Right outputs of the FP24.
w Recording dialog in mono.
Left and Right Positions�Secondary audio source. Monitors
w Performing amix minuso by routing Input 1 to Center and
audiofrom the Tape Return input of the FP24. Can be used to verify
Input 2 to Right. A summed mono signal of both inputs
that signal is reaching cameras and tape machines. Left is locking;
appears at the Right output while only Input 1 appears at
right is momentary.
the Left output. This is useful for post production processing
of Input 1 audio.Important: The FP24 can drive headphones to very high levels.
Exercise care when monitoring. Reduce the level when the Head-
phone Peak LED illuminates.
4 |
ACEC
