One of my client's 1100's took out an amp channel of a Lexicon 125 watt mono amp at the end of last year and is now shutting down an additional channel that we utilized. After the amp resets, the speaker plays fine for several days, then shuts down the amp channel again. Any ideas?
Thanks for any advice.
Thanks for any advice.
I’m sorry to report that your description of the problem does not point to anything immediate…no ‘aha’ moment here!
Does the amplifier’s shut-down occur only during loud music, or seemingly at random, or is there any pattern to when it shuts down? Do both speakers sound identical before the shut-down? Does the amplifier channel driving the ‘bad’ speaker run warmer than the other channel? Are there any warning signs before the amp shuts down, like a reduction in volume or crackling noises?
Assuming that you have already examined the innards of the interface for any obvious burnt parts, or signs of arcing around the transformer, board, or high voltage wiring, the first step in troubleshooting would be to measure the DC resistance of the speaker, and compare it to the measurement of the good speaker. Furthermore, since the speaker is bi-amp/bi-wire capable, you can separate the woofer and ESL circuits by placing the switch in the biamp position. You can then make separate measurements of the woofer and ESL’s resistance from the corresponding binding posts. You may measure a few tenths of an ohm difference between two ‘good’ speakers, but much more than that is probably a sign of trouble. When you make the measurements, make sure the HF balance switch is in the same position on both speakers.
Also check for signs of DC voltage on the output of the amplifier. Even though you have changed to a different amp channel, there could be DC being fed from the preamp or source component.
That’s all I can think of for now, lacking any further info. Do write again when you’ve had a chance to investigate some of the items above.
Does the amplifier’s shut-down occur only during loud music, or seemingly at random, or is there any pattern to when it shuts down? Do both speakers sound identical before the shut-down? Does the amplifier channel driving the ‘bad’ speaker run warmer than the other channel? Are there any warning signs before the amp shuts down, like a reduction in volume or crackling noises?
Assuming that you have already examined the innards of the interface for any obvious burnt parts, or signs of arcing around the transformer, board, or high voltage wiring, the first step in troubleshooting would be to measure the DC resistance of the speaker, and compare it to the measurement of the good speaker. Furthermore, since the speaker is bi-amp/bi-wire capable, you can separate the woofer and ESL circuits by placing the switch in the biamp position. You can then make separate measurements of the woofer and ESL’s resistance from the corresponding binding posts. You may measure a few tenths of an ohm difference between two ‘good’ speakers, but much more than that is probably a sign of trouble. When you make the measurements, make sure the HF balance switch is in the same position on both speakers.
Also check for signs of DC voltage on the output of the amplifier. Even though you have changed to a different amp channel, there could be DC being fed from the preamp or source component.
That’s all I can think of for now, lacking any further info. Do write again when you’ve had a chance to investigate some of the items above.
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