10 Khz Square Wave Response; Odep Limiting; Odep Limiting Wave Form; Crosstalk - Crown Macro-Tech MA-2402 Service Manual

130445-1 Rev. A

5.3.8 10 kHz Square Wave Response

Spec: No overshoot, ringing, or oscillations. Slew rate
17 - 25 V/µS into 8 ohm load.
Procedure: Load the channel under test to 8 ohms. In-
ject a 10 kHz square wave to obtain 35 volts zero-to-
peak at the output. Observe the wave form. It must not
include overshoot (<23mV), ringing, or any type of os-
cillation. Rise time should be between 17 and 25 volts
per microsecond. See Figure 5.3 for typical 10 kHz
square wave response.

5.3.9 Crosstalk

Spec: 60 dB below 8 ohm rated power at 20 kHz, 85
dB below 8 ohm rated power at 1 kHz and below.
Initial Conditions: Per standard. Terminate input of chan-
nel not driven with 600 ohms.
Procedure: Load each channel to 8 ohms. Inject a 20
kHz sine wave into Channel 1 and increase the level to
63 VAC at the output. Measure less than 63 millivolts
AC at the output of Channel 2. Inject a 1 kHz sine wave
into Channel 1 and increase the level to 63 VAC at the
output. Measure less than 3.6 millivolts AC at the output
of Channel 2.Repeat for Channel 2 by driving channel
2 and terminating Channel 1. Measure less than 63 mil-
livolts at the output of Channel 1 at 20 kHz, and 3.6
millivolts at 1 kHz.

5.3.10 Output Power

North America:
Spec at 8 Ohm Stereo: >= 520W at 0.1% THD.
Spec at 4 Ohm Stereo: >= 800W at 0.1% THD.
.
Spec at 2 Ohm Stereo: >= 1050W at 0.1% THD.
Figure 5.3 10 kHz square wave response
©2000 Crown International, Inc.
International:
Spec at 8 Ohm Stereo: >= 512W at 0.1% THD.
Spec at 4 Ohm Stereo: >= 742W at 0.1% THD.
Spec at 2 Ohm Stereo: >= 924W at 0.1% THD.
Procedure:
North America: Load each channel to 8 ohms. Inject a
1 kHz sine wave and measure at least 64.50 VAC at the
output of each channel. Load each channel to 4 ohms.
Inject a 1 kHz sine wave and measure at least 56.57
VAC. Load each channel to 2 ohms. Inject a 1 kHz sine
wave and measure at least 45.82 VAC. All power mea-
surements must be at less than 0.1% THD.
International: Load each channel to 8 ohms. Inject a 1
kHz sine wave and measure at least 64.0 VAC at the
output of each channel. Load each channel to 4 ohms.
Inject a 1 kHz sine wave and measure at least 54.5
VAC. Load each channel to 2 ohms. Inject a 1 kHz sine
wave and measure at least 43.0 VAC. All power mea-
surements must be at less than 0.1% THD.

5.3.11 ODEP Limiting

Spec: Clean limiting into a resistive load (see Figure
5.4).
Procedure: Load each channel to 4 ohms. Inject a 50
Hz sine wave into each channel and increase the level
for 20 VAC at the output. Stuff a rag into the fan to pre-
vent the fan from turning. Observe the wave form on an
oscilloscope. After about 1 minute ODEP limiting will
occur (see Figure 5.4). Once limiting occurs the wave
form will collapse at a rapid rate. Make sure both chan-
nels limit. Remove the load and signal, remove the rag
from the fan, and allow the amp to cool.
Figure 5.4 ODEP limiting wave form
MA-2402 Service Manual
Maintenance 5-3