User manual

AMP2-DA Instruction and Service Manual P/N 821505 Rev-B

1) Removal of the Top Cover

Remove the top cover screws (2 along upper front panel, 2 per each side, 3 along upper rear panel). The 919126 PCB is vertically

mounted to chassis bottom just behind the front panel mounted LED driver PCB (see photo below).

2) Adjustment Pot Locations and Functions

On the 919126 PCB(s) the P2 pot adjusts the left (Channel A) bargraph meter and the P3 pot adjusts the right (Channel B) bargraph

meter. See diagrams below.

3) “0” Fine Adjustment Setup

Connect a test signal of approximately 1 kHz of the amplitude desired to give a “0” indication on the bargraph. This signal should

be connected across the balanced inputs, and should be from a balanced source.

4) Fine Adjustment of the Bargraph “0” Level

Turning each pot clockwise increases the displayed level (sensitivity) of the associated bargraph meter. For example, to set

the zero level at +7 dBu (rather than the factory default setting of +4 dBu), adjust the appropriate DIP switch for gain closest

to that desired (see page 22 for Gain Calibration settings). Feed a +7 dBu signal (see step 3) into the analog input on the rear

panel (Item F, page 16), then turn the pots counter-clockwise as you visually monitor the associated bargraph meter on the front

panel until the desired display setting (“0”) is achieved for the increased input level. To zero the meters for a lower input level,

you would turn the pots clockwise to increase the displayed level for any decreased input level.

Note: For range setting, use the Meter Input Gain Calibration/Bargraph Display Mode DIP Switches

Level Meter Bargraph "0" (zero) Fine Adjustment

P2 pot adjusts the left bargraph meter.

P3 pot adjusts the right bargraph meter.

Turn pots clockwise to

increase the display level (sensitiv-

ity) in the associated bargraph meter

Section 3: Technical Information

R10

R12

IC5