Offset Calibration - powersoft IpalMod Service Manual

IPALMOD | SERVICE MANUAL
Audio Tests
Connect a function generator to the inputs (CN11.
By means of the DigiMod Mains DC Cable, connect a
Variac to the CN4 Connector, and slowly increase the
voltage to 100 VAC.
Generate a 8/32 Burst Signal @ 0.5 Vrms - 100Hz
Connect an oscilloscope to output 1 and confront the
resulting wave, repeat the operation with the remaining
channel.
In both cases the reading from the oscilloscope should
show an 8/32 Burst signal. (Fig. 27)
Once all these tests are carried out successfully, connect
a 1000W 8Ohm Load to the outputs and leave the unit on
for at least 10 minutes (per channel).
If the module passes all the tests, solder in place the
JP6 jumper highlighted on (Fig. 28)

8. Offset calibration

Switch the module on in AC.
Turn the potentiometer on the DPC interface board
completely clockwise.
Plug a Function Generator into the input connector of
the DPC interface board. (Fig. 29)
Feed a stationary 100 Hz Sine Wave and calibrate the
output level in order to have 1 V
NO LOAD MUST BE CONNECTED DURING THE
CALIBRATION PROCEDURE!
Turn the indicated trimmer on the DSP board until the
highlighted D8 red LED turns off. (Fig. 30)
16
(0 dBV, 2.21 dBu).
rms
8/32 Burst
CN11
(Fig. 27)
(Fig. 28)
100 Hz Sine
(Fig. 29)
(Fig. 30)