CE Series Service Manual
Rev. D
WARNING: Many of the following checks are done by connecting a resistive load to the output of the
amplifier. Use caution and follow check-out procedures carefully to ensure correct results. These
tests require a resistive load capable of over 2000 W continuous into as low as 2 ohms.
WARNING: The CE-Series is capable of drawing in excess of 30 Amperes of current from 120VAC
mains when loaded to 2 ohms per channel and with both channels driven by a 1 kHz sine wave.
For tests numbered 10-15 the main module should be placed back into the chassis if at all possible.
Otherwise, the heatsinks will become very warm, causing the amplifier to thermally protect itself. It is
also possible under high-power bench testing to trip the front panel circuit breaker. Also, with the
module removed from the chassis, test #14, Fan Operation, will not be able to be performed.
Make sure the sensitivity switch is set to 26 dB. Note:
Operation with a sine wave into a low-impedance load
will cause the circuit breaker to trip after 10 to 20 sec-
onds.
AC Mains of 120 VAC, 60-Hz
8-Ohm Load: Minimum voltage is 46.9 Vrms (275W)
with <0.5% THD for the CE 1000 and 56.6 Vrms (400W)
with <0.5% THD for the CE 2000.
4-Ohm Load: Minimum voltage is 42.4 Vrms (450W)
with <0.5% THD for the CE 1000, and 51.3 Vrms (660W)
with <0.5% THD for the CE 2000.
2-Ohm Load: Minimum voltage is 33.4 Vrms (560W)
with <0.5% THD for the CE 1000, and 44.1 Vrms (975W)
with <0.5% THD for the CE 2000.
You may need to adjust your variac back up to nominal
line voltage during these tests. Place the sensitivity
switch in the 26-dB position. Use a 60-Hz/7-kHz (stan-
dard SMPTE IM signal) input signal summed in a 4:1
ratio. Set the 60-Hz portion for 33.9 Vrms at the output
of the channel under test for the CE 1000, or 40.8 Vrms
at the output of the channel under test for the CE 2000.
This is your 0-dB reference. Measure the I.M. distor-
tion. Check in -5 dB (power) steps until -35 dB is
reached. Readings should be less than 0.1% at each
level.
10. 1-kHz Power + THD 1-kHz Sine Wave
Various Loads
11. Intermodulation I.M. Signal Source
Distortion (I.M.D.) 8-ohm Load
Type of Test Input Signal and Comments
or Adjustment Load Parameters
Maintenance 2-7
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