dbx 3BX III, Руководство по обслуживанию

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Model 3BX III Service Manual
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7.4.6 High-Band Distortion
Repeat the steps in 7.4.5 using 10 kHz at –10 dBV (316 mV
rms).
7.5 Noise
7.5.1 Set the unit as in 7.4.1
7.5.2 Disconnect all sources from the 3BX III and connect 1 k-ohm
resistors from the input terminals to the input ground (RCA, or
phono [pin], plugs with 1 k resistor terminations are ideal).
7.5.3 Connect one channel output of the 3BX III to the input of the
rms-responding AC voltmeter.
7.5.4 Verify that the noise level is less than –85 dBV unweighted
or –90 dBV A-weighted. (0 dBV is 1 V rms.)
7.6 Muting Check
7.6.1 Set the unit as in 7.4.1
7.6.2 Connect the sine-wave oscillator, set to 100 Hz at 0 dBV (1 V
rms), to both inputs of the unit.
7.6.3 Connect the oscilloscope to the output of one channel of the
unit, with its front controls turned down. Set scope to 0.5 V/div
and 100 ms/div.
7.6.4 Power the unit up and down a few times to confirm that the
output-mute circuitry is working, as shown in Fig. 11.
7.6.5 Check the other channel, too.
Power on Figure 11 Power off