Fostex PD204 Owner's Manual page 81

<Notes>
• Adjust the recording level appropriately so that the level meter does not exceed "0 dB" but
goes up near to the "0 dB" at the loudest part of the signal.
The reference level is set to "-20 dB" by default. This means a +4 dBu signal indicates 20 dB
down from the 24-bit full-scale level (0 dB) on the level meter.
• You can set to generate the error tone when the input amplifier clips using the "Error tone"
menu item in the "SYS SETUP" menu of the MENU mode (see page 160).
The PD204 controls the gain by the advanced digital control volume with the latest
technology, which offers the following advantages.
(1) Improvement of audio quality by simplifying the analog circuit.
(2) Controls the volume of an input signal and can be used as an analog limiter with no
sound deterioration unlike a conventional VCA limiter.
This volume control provides the zero-crossing control function which restrains an
unwanted stepping noise.
<Zero-crossing control function>
The zero-crossing is the instantaneous
point at which there is no voltage present
(indicated by arrows in the figure on the
right). The zero-crossing control function
alters the audio level at the zero-crossing
point to prevent generating a stepping
noise of a digitally controlled volume.
<Note on gain adjustment>:
detect zero-crossing points, resulting generating a small amount of the stepping noise.
On channels 1 through 4, the limiter function is achieved by automatically controlling
the digital control volume on each channel. (Note that the ST BUS channel limiter
works differently.)
<Notes on using the limiter function>:
a small amount of the stepping noise may be generated in the following conditions.
(1) When a single low frequency signal is fed.
(2) When channels are linked and the limiter on the channel with no input signal works.
If you hear the stepping noise in the condition as above, we recommend that you do not
use the limiter function of the PD204 or you use an external limiter.
<About gain adjustment>
0V
When no signal or very low-level signal is fed, the unit may not
<Limiter function>
Due to the nature of the digitally-controlled volume,
Location Recorder Model PD204
Chapter 5: Recording/Playback
81