Cap2100: Phono Board Detection And Gain Test; Listening For Noise; Pops And Whistles Check; Ca2100: Rs-232 Function Test - Classe Audio Delta Series Service Manual

CAP2100: Phono board detection and gain test

Plug in two phono test circuits and make sure they are detected by the unit (the display will show "phono"
instead of "Line 1". (If one of the test circuits is not detected then there will be an error message). In the menu
got to "system setup" and select the "phono gain" option. When you select HIGH gain the LED on the plug-
in jig should light up (there will be 6Vdc on pin 5 of J102 and J301 relative to ground). When you select
LOW gain the LED on the plug-in jig should go off (the voltage on pin 5 will go to zero).

Listening for noise

These tests will require some ear-training. If in doubt, compare your noise level with a "reference" unit or ask
a "reference technician.
For a CA2100
Insert 50-ohm terminators into the XLR inputs of the amplifier and listen closely to all the outputs with a 4-ohm
speaker (with the amplifier ON). The noise floor should be barely audible when the speaker almost touches
your ear. If you hear anything it should be very low-level white noise (no power related artifacts like hum or
buzz). Repeat the same test in single-ended mode (power-down, switch the input selection, insert 25 ohm
terminators into the RCA inputs of the amplifier, and power back up).
Repeat both tests without input terminators. There will be more noise but make sure it is not power-related
hum or buzz and at about the same level in all channels.
For a CAP2100
Be sure that your RS-232 cable is unplug from the unit during the noise/pop test.
Connect a 4 ohms speaker to the unit. Turn on the unit. Put volume to 40dB. Press MUTE button. You
shouldn't hear anything or just a little volume chip noise (a kind of tic tic tic...). If you think is too much, try
with a B&W speaker. Listen to the noise from about 1 foot from the speaker, if you still can hear something,
change the volume chip of the related channel. Repeat the test but, by pressing another line selection
(exemple: Line 1 to Balanced). After, redo the test for the other channel.

Pops and whistles check

Connect a B&W speaker to one output. Power-up the unit from cold (caps fully discharged) and verify that the
speakers don't pop during the power-up sequence. Power-down and listen for pops and/or whistling sounds
(like caps discharging) on the speaker. Repeat the test with a "warm" start (don't discharge the caps). After,
redo the test with the other output channel.

CA2100: RS-232 function test

Connect an RS-232 cable from the serial port of a computer to the amplifier. Start DCI (Delta Classé
Interface) on the computer. As soon as you power up the unit, the DCI window will display the state of the
unit. As soon as this communication is established, you can check some circuits with the software. Use the
following commands:
Click on FAC to see the factory data.
Click on SDP to check the AC power. Make sure that all the readings are reasonable (e.g. current at
zero while in standby) and stable, and that there are no error messages.
Click on LPI to see the programmable limit data. If a control module does not communicate with the
front panel then you will see an error here.
Click on PWR to start (or stop) the amplifier.
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