Electro-Voice Precision P3000, Service Manual

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(100 ms ON, 900 ms OFF), applied to each channel at a time. The protection circuit has to react. The power
amplifier tries to re-start continuously while the PROTECT LED blinks with the same frequency.
Repeat the test with
f = 30 kHz and the limiter set to ON; the power amplifier should not switch off.
6. Level CHANNEL A&B:
• set the level control to its fully clockwise position.
• set the INPUT ROUTING switch to: DUAL / STEREO.
• HI-LOW-CUT switch is ON (as factory pre-set!).
• BRIDGED MODE: NORMAL
• LIMITER: SLOW (as factory pre-set!)
• THD < 0.1 %
6.1. NOMINAL LEVEL
Input U(E) Measuring point U(A) Load resistor Jumper on
86207/86211
CH. A/B 0 dBu SPEAKER A/B 69.3 V 4 Ohm select J11,J21
CH. A/B + 6 dBu SPEAKER A/B 69.3 V 4 Ohm select J12,J22
CH. A/B + 13 dBu SPEAKER A/B 69.3 V 4 Ohm select J13,J23
CH. A/B +1 dBu SPEAKER A/B 77.5 V 8 Ohm select J11,J21
CH. A/B -2 dBu SPEAKER A/B 54.8 V 2 Ohm select J11,J21
6.2. MAXIMUM INPUT LEVEL: U(E) = +21 dBu (9 Vrms)
7. INPUT-ROUTING switch
DUAL / STEREO (as factory pre-set!)
- channel A and B have to be driven separately.
PARALLEL / MONO
- channel A and B are paralleled at the input. Both channels can be driven using a common signal source.
8. Level BRIDGED MODE
• set the level control all the way to its fully clockwise position.
• HI-LOW-CUT switch is ON (as factory pre-set!).
• BRIDGED MODE: BRIDGED
• LIMITER: SLOW (as factory pre-set!)
• THD < 0.1 %
BRIDGED: Double the output voltage is presented at the BRIDGED OUT connector. It is mandatory to use the
CHANNEL A input connector. The CHANNEL B input connector is without function.
Input U(E) Measuring point U(A) Load resistor Remarks
CH. A 0 dBu BRIDGED OUT 109.5 V 4 ohms select J11,J21
CH. A 0 dBu BRIDGED OUT 138.5 V 8 ohms select J11,J21
9. GROUND LIFT switch
Test the functioning of the switch using an ohm-meter:
The circuit ground (at the input or the output connector) is measured versus the common ground of the enclosure
(contact at the ground terminal, located on the rear panel - or common ground of the mains cord).
10. Amplitude - Non-Linearity
• testing with load resistor 8 ohms, dual mode
• MDW = 80 kHz
• input sensitivity = 0 dBu
• power amplifier's condition as shipped from the factory
Measurement at nominal voltage
U(A) = 63.2 V
at nominal voltage
U(A) = 20 V
Remarks
THD+N ( f = 1 kHz )
< 0.005 % < 0.005 %
THD+N ( f = 10 kHz) < 0.02 % < 0.01 %
IMD-SMPTE < 0.01 % < 0.01 % 60 Hz, 7 kHz
DIM 30
< 0.007 % < 0.005 % 3.15 kHz, 15 kHz