It's just that that specific channel was much quieter than the other 7. No matter what output from the processor was feeding it, its volume was lower. It was a very drastic difference. That channel had to be adjusted to +11 or so in the processor while all of the other channels were around -7 or -8 to get the same SPL.
I gather that was a problem in a few of the early amps. My early lab amp also developed that issue. It was caused by a defective relay switch in one of the channels which was easily fixed by substituting a properly functioning new switch. Subsequent batches of relays are fine.
The Audessey incompatibility is another matter. From what I understand the problem is caused by the way the Audessey software keeps raising gain to test frequency response. If the preamp volume is set too high to start with, the DSP in the a-1400 triggers a safety shutdown to keep the amp from allocating excessive voltage. It doesn't appear to be a problem with auto-equalization programs other than Audessey. A simple solution would be to run Audessey at a lower volume say 65db instead of 75db.
There should be an addendum in the manual regarding Audessey.
