Alto AMX-80, Руководство по обслуживанию, Страница: 12 / 20

7. AMX-80 TEST PROCEDURE
1. Test instruments:
1). AP ( Audio precision )
2).Dual track oscilloscope
3. Volt meter
2. Instrument setting:
1). AP output : 0dBu 1Khz SINE wave, Load out 40
ȍ
Bal-Float or Load out 600
ȍ
BNC-Unbal.
2). AP input : Load 100K
ȍ
BNC-Unbal or Load 100K
ȍ
Bal-Float BW
Κ
22Hz~22KHz. Fltr
Κ
A-Weighting(1207)
3. Visual Check:
1). Check the AMX-80 surface; and be sure no friction of all pots.
4. Functions Test:
1). Set all knob to 0 position, TRIM to minimum , and MAIN MIX LEVEL to middle position.
2). Set AP output to -30 dBu, connecting unbalanced input to LINE IN 1, unbalanced output
to MAIN OUTPUT, then the output LEVEL should be -45dBu(±3dBu)
Set TRIM to maximum, output LEVEL should be 0dBu(±3dBu)
(After test set TRIM back to minimum)
3). Set AP output to +15dBu, connecting unbalanced input to LINE IN 1, unbalanced output to
MAIN OUTPUT, then the output LEVEL should be 0dBu(±3dBu) THD+N<0.005%.
Rotate CH LEVEL to maximum, output LEVEL should be +15dBu (±3dBu)
THD+N<0.005%.
(After test set CH LEVEL back to middle position)
Rotate MAIN MIX LEVEL to maximum, the output LEVEL should be +15dBu (±3dBu)
THD+N<0.008%.
(After test set MAIN MIX LEVEL back to middle position, and CH LEVEL to minimum.)
4). Set AP input to 0dBu, connecting unbalanced input with LINE2/3~LINE4/5, unbalanced
output to MAIN OUTPUT, then the output LEVEL should be 0dBu (±3dBu) THD+N<0.005%.
Rotate CH LEVEL to maximum, the output should be +15dBu (±3dBu) THD+N<0.005%.
(After test set CH LEVEL back to middle position)
5). Set AP input to 0dBu, connecting balanced input to MIC1, and the unbalanced output to
MAIN OUTPUT, then the level should be 0 dBu (±3dBu), THD+N<0.005%. (After test set CH
LEVEL back to middle position)
Set the MAIN MIX LEVEL knob to maximum, the output level should be +15dBu (±3dBu),
THD+N<0.008%. (After test set MAIN MIX LEVEL back to middle position. And set the CH
LEVEL to minimum. )
6). Set AP input to +15dBu, connecting unbalanced input to LINE IN1, and the unbalanced
output to PHONES, the output level should be 0dBu(±3dBu) THD+N<0.01%.
Rotate the CH LEVEL to maximum, output level should be +15dBu (±3dBu),
THD+N<0.006%.( After test set the knob to central position )
Set the MAIN MIX LEVEL to maximum, the output level should be+15dBu (±3dBu),
THD+N<0.01%.( After test set the knob to central position)
- 9 -