Fostex PD204 owner manual About gain adjustment, Limiter function, Zero-crossing control function

Chapter 5: Recording/Playback

<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).

<About gain adjustment>

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 0V 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>: When no signal or very low-level signal is fed, the unit may not detect zero-crossing points, resulting generating a small amount of the stepping noise.

<Limiter function>

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>: Due to the nature of the digitally-controlled volume, 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.

Location Recorder Model PD204 81