Electro-Voice STEREO POWERED MIXER PSX1000, Service Manual, Page: 11 / 89

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continuously! The protect-LED lights.
- Repeat the test using a test signal of f = 14 Hz. The power amplifier has to stay in operation.
5.8 HIGH FREQUENCY PROTECTION CIRCUIT TEST:
Caution: Operate the power amplifier under all circumstances without load resistors connected. Apply to one
power amplifier channel at the time a sine burst of f = 80 kHz (40 ms ON, 960 ms OFF) with +20 dBu. The
protection circuit has to respond and the power amplifier tries to re-activate continuously. The PROTECT-LED
blinks rhythmically. Repeat the test with
f = 50 kHz . The power amplifier has to stay in operation.
6. Level
All level controls within the signal path fully open.
Input U(E) Output U(A) remarks
MIC Mono -60 dBu INSERT Mono 0 dBu Gain max.
LINE Mono -54 dBu SPEAKER L&R 44.7 V EQ Bypass
INSERT RETURN Mono -14 dBu SPEAKER L&R 44.7 V
MIC Stereo -60 dBu MAIN INSERTS +4 dBu
LINE Stereo L/Mono -34 dBu MAIN OUTPUT L&R +6 dBu
LINE Stereo R -34 dBu MAIN OUTPUT R +6 dBu
STEREO RET. L/Mono -24 dBu EQ OUTPUT L&R +2 dBu EQ ON
STEREO RET. R -24 dBu EQ OUTPUT R +2 dBu EQ ON
2 TRACK RET. -24 dBu MONO OUTPUT 0 dBu
LINE Mono -44 dBu REC. SEND 0 dBu
2 TRACK RET. -20 dBu AUX3 SEND -12 dBu
LINE Mono -60 dBu AUX1 SEND +20 dBu
LINE Mono -60 dBu AUX2 SEND +20 dBu
LINE Mono -60 dBu AUX3 SEND +5 dBu AUX3 PRE
LINE Mono -60 dBu AUX3 SEND +15 dBu AUX3 POST
LINE Stereo L/Mono -44 dBu AUX3 SEND +0 dBu AUX3 PRE
LINE Stereo L/Mono -44 dBu AUX3 SEND +8 dBu AUX3 POST
LINE Stereo L/Mono -44 dBu AUX1 SEND +13 dBu FX1 off
LINE Stereo L/Mono -44 dBu AUX2 SEND +13 dBu FX2 off
LINE Mono -44 dBu PHONES L&R +8 dBu PFL CHANNEL engaged
LINE Stereo L/Mono -24 dBu PHONES L&R +8 dBu PFL CHANNEL engaged
LINE Stereo L/Mono -24 dBu PHONES L&R +18 dBu PFL MASTER engaged
LINE Stereo L/Mono -34 dBu PHONES L&R +11 dBu PFL AUX3 engaged /AUX3 PRE
POWER AMP INPUT L&R + 6 dBu SPEAKER L&R 44.7 V no distortion
7. Amplitudes and non-linearity
•
measurement of the power amplifier with an 8 _ load resistor, one channel driven.
•
MBW = 80 kHz,
•
DIM 30: 3.15 kHz, 15 kHz
•
SMPTE: 60 Hz, 7 kHz, 4:1
input output THD+N
@ 1 kHz THD+N
@ 10 kHz DIM 30 SMPTE remarks
MIC Mono/Stereo EQ OUTPUT L&R <0.005 % <0.02 % <0.01 % <0.01 % U(A) = 16dBu
LINE Mono EQ OUTPUT L&R <0.005 % < 0.02 % < 0.01 % < 0.01 % U(A) = 10 dBu
LINE STEREO EQ OUTPUT L&R <0.005 % < 0.02 % < 0.01 % < 0.01 % U(A) = 10 dBu
POWER AMP IN SPEAKER OUT L&R < 0.03 % < 0.1 % < 0.01 % < 0.01 % Pab = 250W
8. Frequency response