Specifications

Prism Media Products Limited AD-2 Dual-rate A/D converter
Operation Manual
Issue 0.2 © Prism Media Products Limited
11 August 1998 Page 21 of 58
will still be clearly visible]. Also, the text display of peak level is updated sufficiently
slowly that the values can be read while the signal amplitude is changing.
Using the [Enter] key the hold mode can be toggled between normal and indefinite
hold. For indefinite hold mode, the peak level displayed in the LCD will not decay but
will be replaced each time higher peak levels are detected.
The highest level measured since indefinite hold was selected will be indicated by a
single LED in the bargraph meter being lit while the dynamic signal level is still
indicated by a moving bar. For test tones, the single LED showing the peak level may
not be evident until the test tone is removed or reduced in level.
4.4.1. Overload threshold
The overload threshold is -0.05dBFS.
The overload need only be present for one sample in order to trigger the overload
detector. This serves as a warning only, and the ultimate test is to listen. Any filtering of
overload indications is regarded by Prism Sound as potentially dangerous.
4.4.2. “Error” indicator
The “Error” indicator may be lit for the following reasons only:
" Digital Input (DI) out of lock : LED on continuously
" Digital Input (DI) experiencing Bi-phase or Parity errors or or sample-slipping :
LED flashing.
4.5. Store Controls
The AD-2 has a large number of control parameters and to simplify and speed up its
operation a system of preset stores is provided, complemented by a menu system for
adjustment of any parameter individually.
The best way of using the AD-2 is to become familiar with the contents of the Factory
Preset stores and to select the one which is the best fit with your requirement. Then you
can customize it by changing just a few parameters.
The configuration can then be saved in one of the user stores for re-use.
The AD-2 stores are organised in two banks of two stores : There are ‘Factory Preset’
and ‘User’ banks in each of the ‘A-D Modes’ and ‘D-D Modes’ banks. The following
table shows the store system organisation: