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G) Mic Amp Test
Push Mic/Line switch, S201, in. Adjust volume control, P201, fully clockwise. Adjust for
20V P/P at pin 1 of J204. The input level to the board should be 5.6mV (+/– 300uV).
Adjust oscillator for 5.6mV and verify that voltage at pin 1 of U202 is equal to 150mV P/P
(+/– 20mV).
H) Mic Amp Frequency Response Test
Adjust for 20V P/P at 400Hz at pin 1 of P204. Adjust frequency to 20kHz and verify 20V
P/P (+/– 1V) at pin 1 of J204. Adjust frequency to 20Hz and verify 14V P/P (+/– 2V) at Pin
1 of J204.
I)
Signal Indicator Test
Set oscillator frequency to 400Hz, S201 to "Mic" position (In). Adjust oscillator level for
300mV P/P on pin 1 of U202. Verify that signal LED, D201 is on. Turn off oscillator and
verify that signal indicator turns off.
J) Peak Indicator Test
Set oscillator frequency to 400Hz, S201 to "Mic" position (In), and Volume control, P201 fully
clockwise. Adjust oscillator level for 20V P/P on pin 1 of P204. Verify that Peak LED,
D203, as well as signal LED, D201 are on. Turn volume control down and verify that Peak
indicator turns off.
Amp Assembly Trouble-shooting
EON Power15 and EON15P-1/230
A) Initial Setup
The easiest way to drive the EON Power15 Main Board is to connect it to a known good
EON Power15 Input Board. Interconnect both boards using a 7-pin cable assembly. Place
the input board in "Line" mode (S201 out). Advance volume control on input board, P201,
fully clockwise. Attach power transformer to J1. If at all uncertain about bias adjustment
being correct, adjust bias control, VR1, fully counter clockwise. Connect the low frequency
output to a 4 ohm load and the high frequency output to a 8 ohm load. Connect Porta-One
generator output A to input board's XLR connector. Generator output A should be turned off.
B) Main Test Loop
Monitor +15V supply while slowly advancing Variac, that is powering primary of power
transformer. Watch the input watt meter, the input volt meter, and the voltmeter on the
+15V supply. Verify the following:
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