I read that the MI254 has a “feature” that automatically shuts off the amp if no signal is received in 30 minutes. This seems like a stupid feature, especially when you use it for its intended purpose of driving surround speakers. The only way to turn this off is if you connect it to a preamp with a trigger input; but then that will turn off the meters, unless you use a Mcintosh preamp, or modify the trigger cable in some way — at least that’s what the other owner said.
Does anyone know more about this?
I guess the auto power-off feature was included as this amp could double as a multi-zone amplifier.
I connected the MI254 power control trigger with the Marantz SR6014 "DC OUT" and it seems to work just fine. The amp turns on/off with the receiver, the auto power-off feature was defeated, and the meter lights works normally.
I've heard about the meter lights/trigger issue as well. McIntosh power control triggers also control meter lights when used in conjunction with McIntosh preamp/processors. This is useful for dark theater rooms with amps on an open rack as the meter lights can be distracting.
It is possible to do a workaround by using a 3.5mm stereo aux cable as opposed to a standard (mono) trigger cable.
Fully inserting the stereo jack into the trigger input = Auto power-off DISABLED, Meter Lights ON
Inserting the stereo jack only halfway (one conductor exposed) = Auto power-off DISABLED, Meter Lights OFF
The green McIntosh logo lights can't be turned off, however.