My only current suggestion is to check your cabling, make sure they are not shorted anywhere. Try using different speaker cables (I have had cables that appear to be fine, but are damaged anyway causing shorts and risking damage to equipment). The JBL L65s and VOT Altecs are efficient speakers, but I cannot find any specifications or bench tests for them as my internet is quite unresponsive at the moment. It is possible that the JBLs and/or Altecs dip very low in impedance at higher levels and lower frequencies. If you have a subwoofer you should be sure the cross-over on the receiver is set to 80hz or higher with the speakers set to "small". I know setting such large speakers to "small" seems to defy logic, but it helps to protect the receiver from low impedance dangers brought on by otherwise very efficient speakers. I am assuming that you don't have a subwoofer, as it wouldn't be very logical with such large speakers that can produce large amounts of bass.
Did you have another receiver connected to these speakers before? If so, what was the make and model of that receiver and did you experiance similar troubles using it as with the H/K. The H/K seems like a very capable receiver, but those speakers, surprising as it may be, may be more than it can handle.
