M•AD-824
Quick-Start Guide
5
8.) Select DITHER & Optional NOISE SHAPING for 16 bit or 20 bit modes.
Dither, ABC-1 and ABC-2 are grouped together (similar to word length).
αβC
αβC
αβC
αβC α
coustic
β
it Correction®
is dither plus psycho-acoustic enhancement of the
converter’s dynamic range for word length reduction to 20 or 16 bits. Some describe
this as getting more than 16 bits performance with a 16 bit word length.
ABC-1
provides a gentler enhancement curve.
ABC-2
provides a more aggressive enhancement curve.
•It is possible to set this function to
none
of the three choices for “no dither or
αβC
αβC
αβC
αβC
.” In this
case, all three lamps will be blinking.
•Setting the position of the internal DIP switch position to “ON” changes ABC-1 and ABC-2
to less aggressive curves. Please refer to the LavryBlue Operations Manual.
9.) METER FUNCTIONS
To Use The Reference Meter Bridge:
Please Note: To use this mode, you need a reference tone source (for example 1kHz) at
“0dB” on your VU meters or at a level that represents the AVERAGE level of the music
source. This level will typically be in the range of 10 to 20dB’s below analog PEAK level.
The range of the meter is “expanded” around the reference level so that each lamp above or
below the reference level indicates approximately 0.2dB of level change.
Select “Reference.” A pair of solidly lit lamps (L and R) indicates the reference level
between -10 and -20dB on the Meters. Click up (Set) to step to the desired REFERENCE
LEVEL (-10, -12, -14, -16, -18 or –20dBFS). Apply the tone to the analog inputs of the
M•AD-824. If the top lamps of the meter are blinking, it means that the analog input level is
ABOVE the meter range, and if the bottom lamps are blinking the tone is BELOW the range.
Use a small screwdriver to adjust the front panel 20-turn pots until the second pair of lamps
stops blinking, and move up or down the scale to coincide with the selected reference level.
Determining the optimum level setting for the trimmers of the MAD module will take some
experimentation. The most important consideration is that the typical peak level of the audio
program you want to record comes very close to, but does not exceed “0dBFS” which is
represented by the “MAX” lamps on the MAD meters. The following procedure uses music
program to roughly determine the optimum level; then allows you to “fine tune” it using the
REFERENCE function.
Once you have established the output gain of the device feeding the MAD module, DO NOT
change it during this calibration procedure.
1.)
Feed music program to the analog inputs which is typical of the type of material you
want to record with the MAD-824. Adjust the trimmers on the front of the MAD
module so that the peak level is close to “0” on the MAD meters, but does not cause
the MAX lamps to illuminate.
